Herb & supplement monograph

Fish Oil Drug Interactions, Uses, Effectiveness, Safety & More

Medically reviewed by ·Updated July 2026
What is this page for?

First and foremost: how Fish Oil interacts with medications. The heart of this page is the interaction list — every drug Fish Oil is known to interact with, and how serious each one is.

But these pages have grown well beyond that into a full monograph — what Fish Oil is, what people use it for and how strong the evidence is, its safety and side effects, and answers to the questions we’re asked most — written and reviewed by the clinical staff at HelloPharmacist. It’s educational information from our licensed clinical databases, not medical advice, and we don’t sell or endorse products. Our editorial policy

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Fish Oil Drug Interactions: The Bottom Line

From the HelloPharmacist Editorial Team · Updated July 2026

Based on the available evidence, the overall risk of a clinically significant Fish Oil drug interaction appears low for most people. None of the listed interactions are rated major, and the best-documented concerns mostly apply to a small group of closely monitored medicines.

Interactions deserving the most attention

The strongest human evidence involves the transplant drugs sirolimus, tacrolimus, and cyclosporine, where fish oil raised blood levels of these narrow-margin medicines, in one study enough that the sirolimus dose had to be reduced. Fish oil can also modestly lower blood pressure, so it may add to the effect of blood pressure medications. With warfarin and other blood thinners, the evidence conflicts: a few case reports suggest a bleeding risk, but studies have not shown a meaningful change in most people.

What the rest of the list means

A long interaction list does not mean every combination is harmful. Many entries are theoretical, based on possible effects on how the body absorbs fats or processes medications, and several predicted effects have not produced meaningful changes in people. Fish oil's mild effects on blood pressure and platelets tend to matter only when a medicine leaves little room for error.

Check your medications against Fish Oil

Based on HelloPharmacist’s Fish Oil interaction data and reviewed under our editorial standards.

Interaction report

Drugs that interact with Fish Oil

327 medications have a known interaction with Fish Oil, graded by severity. Select any drug for the full evidence-based detail.

2,830 drugs
AcebutololRhotral, Sectral
Moderate Antihypertensive Drugs

Theoretically, taking fish oil with antihypertensive drugs might increase the risk of hypotension.

Read the full Fish Oil + Acebutolol interaction Acebutolol drug page: uses, dosage & side effects
AcetazolamideAk-Zol, Diamox
Moderate Antihypertensive Drugs

Theoretically, taking fish oil with antihypertensive drugs might increase the risk of hypotension.

Read the full Fish Oil + Acetazolamide interaction Acetazolamide drug page: uses, dosage & side effects
AliskirenTekturna
Moderate Antihypertensive Drugs

Theoretically, taking fish oil with antihypertensive drugs might increase the risk of hypotension.

Read the full Fish Oil + Aliskiren interaction Aliskiren drug page: uses, dosage & side effects
AmbrisentanLetairis, Volibris
Moderate Antihypertensive Drugs

Theoretically, taking fish oil with antihypertensive drugs might increase the risk of hypotension.

Read the full Fish Oil + Ambrisentan interaction Ambrisentan drug page: uses, dosage & side effects
AmilorideAmilamont, Midamor
Moderate Antihypertensive Drugs

Theoretically, taking fish oil with antihypertensive drugs might increase the risk of hypotension.

Read the full Fish Oil + Amiloride interaction Amiloride drug page: uses, dosage & side effects
Amiloride, HydrochlorothiazideAmil-Co, Amilzide, Moduret 25, Moduretic
Moderate Antihypertensive Drugs

Theoretically, taking fish oil with antihypertensive drugs might increase the risk of hypotension.

Read the full Fish Oil + Amiloride, Hydrochlorothiazide interaction Amiloride, Hydrochlorothiazide drug page: uses, dosage & side effects
AmlodipineNorliqva
Moderate Antihypertensive Drugs

Theoretically, taking fish oil with antihypertensive drugs might increase the risk of hypotension.

Read the full Fish Oil + Amlodipine interaction Amlodipine drug page: uses, dosage & side effects
Amlodipine BenzoateKaterzia
Moderate Antihypertensive Drugs

Theoretically, taking fish oil with antihypertensive drugs might increase the risk of hypotension.

Read the full Fish Oil + Amlodipine Benzoate interaction Amlodipine Benzoate drug page: uses, dosage & side effects
Amlodipine BesilateIstin
Moderate Antihypertensive Drugs

Theoretically, taking fish oil with antihypertensive drugs might increase the risk of hypotension.

Read the full Fish Oil + Amlodipine Besilate interaction
Amlodipine BesylateNorvasc
Moderate Antihypertensive Drugs

Theoretically, taking fish oil with antihypertensive drugs might increase the risk of hypotension.

Read the full Fish Oil + Amlodipine Besylate interaction Amlodipine Besylate drug page: uses, dosage & side effects
Amlodipine Besylate, BenazeprilLotrel
Moderate Antihypertensive Drugs

Theoretically, taking fish oil with antihypertensive drugs might increase the risk of hypotension.

Read the full Fish Oil + Amlodipine Besylate, Benazepril interaction
Amlodipine, CelecoxibConsensi
Moderate Antihypertensive Drugs

Theoretically, taking fish oil with antihypertensive drugs might increase the risk of hypotension.

Read the full Fish Oil + Amlodipine, Celecoxib interaction
Ammonium ChlorideAmmonium Chloride
Moderate Antihypertensive Drugs

Theoretically, taking fish oil with antihypertensive drugs might increase the risk of hypotension.

Read the full Fish Oil + Ammonium Chloride interaction
AprocitentanTryvio
Moderate Antihypertensive Drugs

Theoretically, taking fish oil with antihypertensive drugs might increase the risk of hypotension.

Read the full Fish Oil + Aprocitentan interaction Aprocitentan drug page: uses, dosage & side effects
AtenololAtenix, Tenormin
Moderate Antihypertensive Drugs

Theoretically, taking fish oil with antihypertensive drugs might increase the risk of hypotension.

Read the full Fish Oil + Atenolol interaction Atenolol drug page: uses, dosage & side effects
Atenolol, ChlortalidoneAtenixCo, Tenoret 50, Totaretic
Moderate Antihypertensive Drugs

Theoretically, taking fish oil with antihypertensive drugs might increase the risk of hypotension.

Read the full Fish Oil + Atenolol, Chlortalidone interaction
Atenolol, ChlorthalidoneTenoretic
Moderate Antihypertensive Drugs

Theoretically, taking fish oil with antihypertensive drugs might increase the risk of hypotension.

Read the full Fish Oil + Atenolol, Chlorthalidone interaction
AzilsartanEdarbi
Moderate Antihypertensive Drugs

Theoretically, taking fish oil with antihypertensive drugs might increase the risk of hypotension.

Read the full Fish Oil + Azilsartan interaction Azilsartan drug page: uses, dosage & side effects
Azilsartan, ChlorthalidoneEdarbyclor
Moderate Antihypertensive Drugs

Theoretically, taking fish oil with antihypertensive drugs might increase the risk of hypotension.

Read the full Fish Oil + Azilsartan, Chlorthalidone interaction
BenazeprilLotensin
Moderate Antihypertensive Drugs

Theoretically, taking fish oil with antihypertensive drugs might increase the risk of hypotension.

Read the full Fish Oil + Benazepril interaction Benazepril drug page: uses, dosage & side effects
Benazepril, HydrochlorothiazideLotensin HCT
Moderate Antihypertensive Drugs

Theoretically, taking fish oil with antihypertensive drugs might increase the risk of hypotension.

Read the full Fish Oil + Benazepril, Hydrochlorothiazide interaction
BendroflumethiazideAprinox, Naturetin, Neo-NaClex
Moderate Antihypertensive Drugs

Theoretically, taking fish oil with antihypertensive drugs might increase the risk of hypotension.

Read the full Fish Oil + Bendroflumethiazide interaction
Bendroflumethiazide, NadololCorzide
Moderate Antihypertensive Drugs

Theoretically, taking fish oil with antihypertensive drugs might increase the risk of hypotension.

Read the full Fish Oil + Bendroflumethiazide, Nadolol interaction
Bendroflumethiazide, Rauwolfia SerpentinaRauzide
Moderate Antihypertensive Drugs

Theoretically, taking fish oil with antihypertensive drugs might increase the risk of hypotension.

Read the full Fish Oil + Bendroflumethiazide, Rauwolfia Serpentina interaction
BenzthiazideExna
Moderate Antihypertensive Drugs

Theoretically, taking fish oil with antihypertensive drugs might increase the risk of hypotension.

Read the full Fish Oil + Benzthiazide interaction
BetaxololBetoptic, Kerlone
Moderate Antihypertensive Drugs

Theoretically, taking fish oil with antihypertensive drugs might increase the risk of hypotension.

Read the full Fish Oil + Betaxolol interaction Betaxolol drug page: uses, dosage & side effects
Birth Control PillsBirth control pills
Moderate Contraceptive Drugs

Theoretically, taking fish oil with contraceptive drugs might decrease the triglyceride-lowering effects of fish oil.

Read the full Fish Oil + Birth Control Pills interaction
BisoprololZebeta
Moderate Antihypertensive Drugs

Theoretically, taking fish oil with antihypertensive drugs might increase the risk of hypotension.

Read the full Fish Oil + Bisoprolol interaction Bisoprolol drug page: uses, dosage & side effects
Bisoprolol, HydrochlorothiazideZiac
Moderate Antihypertensive Drugs

Theoretically, taking fish oil with antihypertensive drugs might increase the risk of hypotension.

Read the full Fish Oil + Bisoprolol, Hydrochlorothiazide interaction
BosentanTracleer
Moderate Antihypertensive Drugs

Theoretically, taking fish oil with antihypertensive drugs might increase the risk of hypotension.

Read the full Fish Oil + Bosentan interaction Bosentan drug page: uses, dosage & side effects
Read The List Like a Pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

  • Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
  • Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
  • Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
  • No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

  • Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
  • Probable. Interaction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • Possible. Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists
  • Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

  • Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
  • Each drug listed above links to the full report for that exact Fish Oil combination — clinical detail, likelihood, evidence level, and citations.
  • Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.
The big picture

The kinds of drugs Fish Oil affects

Every type of medication (drug category) Fish Oil is known to interact with. Open any category for the detail — or search your exact drug in the checker above.

All 9 drug categories Fish Oil interacts with
Antihypertensive DrugsContraceptive DrugsCyclosporine (neoral, Sandimmune)Orlistat (xenical, Alli)Sirolimus (rapamune)Tacrolimus (prograf)Anticoagulant/antiplatelet DrugsPlatinum AgentsWarfarin (coumadin)
Antihypertensive Drugs

Theoretically, taking fish oil with antihypertensive drugs might increase the risk of hypotension.
Clinical evidence indicates that fish oils can modestly lower blood pressure and might have additive effects in patients treated with antihypertensives.

Likelihood Probable Evidence B
Contraceptive Drugs

Theoretically, taking fish oil with contraceptive drugs might decrease the triglyceride-lowering effects of fish oil.
There is some evidence that contraceptive drugs might interfere with the triglyceride lowering effects of fish oils.

Likelihood Probable Evidence B
Cyclosporine (Neoral, Sandimmune)

Taking fish oil with cyclosporine might increase levels and adverse effects of cyclosporine.
In kidney transplant recipients on a general immunosuppressive regimen, taking omega-3 fatty acids daily seems to increase peak blood levels of cyclosporine when compared with placebo. This increase was as much as 20% after one month. However, the area under the curve was not significantly affected.

Likelihood Probable Evidence B
Orlistat (Xenical, Alli)

Theoretically, taking fish oil with orlistat might decrease the absorption of fish oil fatty acids.
Orlistat binds lipase in the gastrointestinal tract and reduces fat absorption. Theoretically, taking fish oil with orlistat might decrease absorption of fish oil fatty acids. To avoid this potential interaction, recommend separating administration of orlistat and fish oil by at least 2 hours.

Likelihood Probable Evidence D
Sirolimus (Rapamune)

Taking fish oil with sirolimus might increase levels and adverse effects of sirolimus.
Pharmacokinetic research shows that omega-3 fatty acids increase exposure to sirolimus in kidney transplant patients on a calcineurin inhibitor-free immunosuppressive regimen. A 25% dose reduction in sirolimus was required to keep patients within the expected trough-concentration window. Researchers hypothesize that this may be due to inhibition of cytochrome P450 3A4 (CYP3A4) by fish oil, although this has not been confirmed in clinical research.

Likelihood Probable Evidence B
Tacrolimus (Prograf)

Taking fish oil with tacrolimus might increase levels and adverse effects of tacrolimus.
In a small group of patients, taking fish oil 2.6 grams (Omacor) daily for 4 weeks increased the 8-hour area under the curve of tacrolimus by 25% when compared with baseline. Peak levels were increased by approximately 22%. Researchers hypothesize that this may be due either to an increase in bioavailability or to inhibition of cytochrome P450 3A4 (CYP3A4) by fish oil, although this has not been confirmed in clinical research.

Likelihood Probable Evidence B
Anticoagulant/Antiplatelet Drugs

Fish oil may have antiplatelet effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs. However, evidence is conflicting.
While fish oil may not be a potent inhibitor of platelet function, high doses of fish oil might have antiplatelet effects. Theoretically, concomitant use of fish oil with anticoagulant or antiplatelet drugs may increase the risk of bleeding. However, the most rigorous research shows that short-term doses of fish oil 10 grams daily or long-term doses of 1.5 grams daily for up to 52 weeks does not increase the risk of bleeding or affect coagulation parameters in chronically ill and vulnerable patients. Other controlled research shows that fish oil does not affect platelet function or increase the risk of bleeding. Some research even suggests that perioperative fish oil use decreases bleeding risk. Some research suggests fish oil does not have additive antiplatelet effects when combined with aspirin, but other clinical evidence suggests that adding fish oil to low-dose aspirin treatment increases antiplatelet effects in patients who are aspirin-resistant. Also, some clinical research seems to show that fish oil has additive antiplatelet effects when used with aspirin and clopidogrel compared to aspirin and clopidogrel alone.

Likelihood Unlikely Evidence B
Platinum Agents

Theoretically, taking fish oil with platinum agents can cause resistance to platinum agents, potentially decreasing their effectiveness.
Platinum-induced fatty acids (PIFAs) are fatty acids secreted from human and mouse stem cells when exposed to platinum-based chemotherapy. Animal research suggests that PIFAs cause resistance to chemotherapy by stimulating lysophospholipid production in the spleen, which interferes with the DNA damage caused by certain chemotherapy drugs. One PIFA, known as 16:4(n-3), has been found in both raw fish and some commercially available fish oil products. Mackerel and herring have high PIFA concentrations, while salmon and tuna have low PIFA concentrations. Levels of PIFA in commercial fish oil products ranged from 0.2- 5.7 microMol. Animal research shows that PIFA-containing fish oil products cause resistance to cisplatin, fluorouracil, irinotecan, and oxaliplatin. It is unclear if all commercially available fish oil products contain PIFAs. Additionally, it is argued that levels of PIFA found in some fish oil products are too low to be of clinical concern. Furthermore, a lack of chemotherapy resistance in countries with high fish intake, such as Greenland, Japan, and Norway, suggest that this interaction may not be clinically significant.

Likelihood Unlikely Evidence D
Warfarin (Coumadin)

Fish oil may have antiplatelet effects and might increase the risk of bleeding if used with warfarin.
Fish oil has antiplatelet effects at high doses. Case reports show elevated INR in patients taking warfarin and fish oil 1-2 grams daily. However, some clinical research shows that taking fish oil 3-6 grams daily does not significantly increase INR in patients taking warfarin.

Likelihood Unlikely Evidence B
Monograph

Fish Oil: Uses, Safety & Side Effects

Medically reviewed by · Reviewed July 2026 ·
The bottom line

Fish oil provides omega-3 fatty acids (EPA and DHA) that are best known for lowering high triglyceride levels. The evidence for other heart and health benefits is mixed, and it is generally well tolerated. Talk with your pharmacist or doctor before starting it, especially if you take blood thinners or have a fish allergy.

Fish Oil
Part used
Oil from fatty fish (such as mackerel, salmon, sardines, and anchovies)
Common forms
Softgel capsules, liquid, gummies, and fortified foods
People commonly use it for
  • High triglycerides
  • Heart health
  • Joint pain and inflammation
  • Brain and eye health
  • Dry eyes

Popular and traditional uses — not proof it works. See “Uses & effectiveness” below for the evidence.

Safety at a glance
OverallLikely safe

Fish oil is generally well tolerated for most adults at typical supplement doses.

PregnancyLikely Safe

When used orally and appropriately. Intake of fish oil during pregnancy does not appear to adversely affect the fetus or nursing infant. One large cli...

Read the full pregnancy detail
BreastfeedingLikely Safe

When used orally and appropriately. Intake of fish oil during pregnancy does not appear to adversely affect the fetus or nursing infant. One large cli...

Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center). Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Jump to a section

Overview

Fish oil is a dietary supplement made from the tissues of oily fish such as mackerel, salmon, sardines, herring, and anchovies. It is a rich source of omega-3 fatty acids, mainly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).

Omega-3 fatty acids are considered important for normal body function, including the heart, brain, and eyes. Because many people do not eat enough fatty fish, fish oil supplements are a popular way to add these fats to the diet.

Fish oil comes in capsules, liquids, gummies, and is sometimes added to fortified foods. There are also prescription versions of purified omega-3s used to treat very high triglyceride levels.

How it works

The active parts of fish oil are the omega-3 fatty acids EPA and DHA. The body uses these fats to build cell membranes and to make signaling molecules that help control inflammation.

Omega-3s are thought to lower triglycerides by reducing how much fat the liver makes and releases into the blood. They may also have mild effects on blood vessel function, heart rhythm, and the way platelets clump together.

Many of the proposed effects on inflammation come from laboratory and animal studies. While these mechanisms are biologically reasonable, they do not always translate into clear benefits in people.

Effectiveness

Does Fish Oil work?

Here’s what the research actually shows for each use — graded by Natural Medicines and reviewed by .

Evidence overview · 128 uses evaluated
1 Effective 10 Possibly effective 18 Leans ineffective 99 Insufficient evidence
How to read these evidence grades

Natural Medicines’ 7-point scale. We show each rating’s label word-for-word.

1EffectiveStrong, consistent evidence it works.
2Likely EffectiveGood evidence, though not yet conclusive.
3Possibly EffectiveSome evidence suggests a benefit.
4Possibly IneffectiveSome evidence it may not help.
5Likely IneffectiveFairly strong evidence it doesn’t help.
6IneffectiveStrong evidence it doesn’t work.
7Insufficient Reliable Evidence to RateToo little research to say either way.
Effective Hypertriglyceridemia
Rating & evidence shown verbatim from Natural Medicines

Oral prescription fish oil products reduce triglyceride levels in patients with hypertriglyceridemia, especially in severe cases. Oral fish oil supplements may reduce triglyceride levels when used in very high doses of up to 12 capsules per dose.

Possibly Effective Angioplasty
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil seems to prevent restenosis when started at least 3 weeks before percutaneous transluminal coronary angioplasty (PTCA).

Possibly Effective Cachexia
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil in doses of 7.5-8.1 grams daily seems to slow weight loss in patients with cachexia. Lower doses might not be effective.

Possibly Effective Cyclosporine-induced nephrotoxicity
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil seems to prevent cyclosporine-induced nephrotoxicity.

Possibly Effective Dysmenorrhea
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil seems to reduce symptoms of dysmenorrhea.

Possibly Effective Gastroenteritis-associated nausea and vomiting
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil during pregnancy seems to be beneficial for preventing gastroenteritis in early childhood. It is unclear if oral fish oil is beneficial for gastroenteritis prevention or treatment in children or adults.

Possibly Effective Heart failure
Rating & evidence shown verbatim from Natural Medicines

Dietary fish oil seems to prevent heart failure. Also, oral fish oil seems to prevent further hospitalization, and possibly mortality, in patients with heart failure.

Possibly Effective HIV/AIDS-related dyslipidemia
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil seems to reduce triglyceride levels in patients with this condition. It is unclear if oral fish oil reduces levels of low-density lipoprotein (LDL) cholesterol in these patients.

Possibly Effective IgA nephropathy
Rating & evidence shown verbatim from Natural Medicines

When used for 2-4 years, oral fish oil seems to slow the rate of renal function loss in high-risk patients. It is unclear if oral fish oil slows renal function loss when used for shorter time periods or in low-risk patients.

Possibly Effective Nonalcoholic fatty liver disease (NAFLD)
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil seems to reduce liver steatosis in adults and children with NAFLD.

Possibly Effective Rheumatoid arthritis (RA)
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil seems to reduce pain and stiffness in patients with RA; however, oral fish oil does not seem to be beneficial for RA prevention when used alone.

Possibly Ineffective Age-related macular degeneration (AMD)
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil does not seem to prevent the incidence or progression of AMD. However, eating fish regularly might help to reduce the risk of AMD.

Possibly Ineffective Angina
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil does not seem to improve cardiovascular outcomes in patients with angina.

Possibly Ineffective Atherosclerosis
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil does not seem to attenuate atherosclerosis progression.

Possibly Ineffective Atopic dermatitis (eczema)
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil does not seem to treat or prevent atopic dermatitis.

Possibly Ineffective Atrial fibrillation
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil does not seem to reduce the risk of new or recurrent atrial fibrillation. Some clinical research suggests that high-dose fish oil may actually increase the risk for new atrial fibrillation.

Possibly Ineffective Bronchopulmonary dysplasia
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil does not seem to prevent bronchopulmonary dysplasia in preterm infants.

Possibly Ineffective Cerebrovascular disease
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil does not seem to prevent cerebrovascular disease.

Possibly Ineffective Cognitive function
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil does not seem to improve cognitive function in most people.

Possibly Ineffective Helicobacter pylori
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil does not seem to aid in the Helicobacter pylori eradication.

Possibly Ineffective Mastalgia
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil does not seem to reduce chronic breast pain.

Possibly Ineffective Multiple sclerosis (MS)
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil does not seem to improve symptoms in patients with MS.

Possibly Ineffective Osteoarthritis
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil does not seem to improve pain or function in patients with osteoarthritis. However, oral fish oil might be beneficial for osteoarthritis-related joint pain in overweight patients.

Possibly Ineffective Pre-eclampsia
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil does not seem to reduce the risk of pre-eclampsia.

Possibly Ineffective Pregnancy-induced hypertension
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil does not seem to reduce the risk for hypertension during pregnancy.

Possibly Ineffective Psychosis
Rating & evidence shown verbatim from Natural Medicines

Most research shows that oral fish oil is not beneficial for the treatment or prevention of psychosis.

Possibly Ineffective Unstable angina
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil does not seem to prevent unstable angina.

Possibly Ineffective Ventricular arrhythmias
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil does not seem to prevent ventricular arrhythmias or prevent mortality in patients with a history of ventricular arrhythmias.

Likely Ineffective Diabetes
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil does not improve glycemic control or prevent cardiovascular outcomes in patients with type 2 diabetes. However, oral fish oil may lower triglyceride levels in patients with type 2 diabetes.

Also studied for 99 conditions — evidence insufficient to rate
Insufficient Reliable Evidence To Rate Acute respiratory distress syndrome (ARDS)
Rating & evidence shown verbatim from Natural Medicines

It is unclear if enteral fish oil is beneficial in patients with ARDS.

Insufficient Reliable Evidence To Rate Age-related cognitive decline
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil prevents age-related cognitive decline.

Insufficient Reliable Evidence To Rate Allergic rhinitis (hay fever)
Rating & evidence shown verbatim from Natural Medicines

It is unclear if taking oral fish oil during pregnancy prevents allergic rhinitis in the child.

Insufficient Reliable Evidence To Rate Alzheimer disease
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial for preventing Alzheimer disease or for improving cognition in those with this condition.

Insufficient Reliable Evidence To Rate Antiphospholipid syndrome-associated miscarriage
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil prevents miscarriage in patients with antiphospholipid syndrome.

Insufficient Reliable Evidence To Rate Antipsychotic-induced metabolic side effects
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial for metabolic side effects related to the use of olanzapine.

Insufficient Reliable Evidence To Rate Asthma
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil prevents or treats asthma.

Insufficient Reliable Evidence To Rate Athletic performance
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil improves athletic performance.

Insufficient Reliable Evidence To Rate Atopic disease
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil does not seem to reduce the odds of a child developing atopic disease when taken during pregnancy.

Insufficient Reliable Evidence To Rate Attention deficit-hyperactivity disorder (ADHD)
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial in children or adults with ADHD.

Insufficient Reliable Evidence To Rate Autism spectrum disorder
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial in prevention or treatment of children or adults with autism spectrum disorder.

Insufficient Reliable Evidence To Rate Autoimmune thyroiditis
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial for autoimmune thyroiditis prevention.

Insufficient Reliable Evidence To Rate Bipolar disorder
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil may be beneficial for symptoms of depression in patients with bipolar disorder. However, taking fish oil does not seem to prevent mood relapses or improve symptoms of mania in these patients.

Insufficient Reliable Evidence To Rate Borderline personality disorder
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial for borderline personality disorder.

Insufficient Reliable Evidence To Rate Burns
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil has only been evaluated in combination with other ingredients; its effect when used alone is unclear.

Insufficient Reliable Evidence To Rate Canker sores
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial for preventing or treating canker sores.

Insufficient Reliable Evidence To Rate Cardiovascular disease (CVD)
Rating & evidence shown verbatim from Natural Medicines

The effect of fish oil on cardiovascular health is controversial. Oral fish oil in doses of up to 4 grams daily does not seem to be beneficial for primary or secondary prevention of CVD. It is unclear whether dietary fish oil or a higher daily dose is beneficial for prevention of CVD.

Insufficient Reliable Evidence To Rate Cataracts
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil prevents the development of cataracts.

Insufficient Reliable Evidence To Rate Chemotherapy-induced peripheral neuropathy
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial for the prevention of peripheral neuropathy in patients receiving chemotherapy.

Insufficient Reliable Evidence To Rate Chronic kidney disease (CKD)
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral or dietary fish oil is beneficial in patients with CKD or for CKD prevention.

Insufficient Reliable Evidence To Rate Chronic obstructive pulmonary disease (COPD)
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial in patients with COPD or for COPD prevention.

Insufficient Reliable Evidence To Rate Cirrhosis
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial in patients with cirrhosis.

Insufficient Reliable Evidence To Rate Cognitive impairment
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil prevents or treats cognitive impairment.

Insufficient Reliable Evidence To Rate Colorectal cancer
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil prevents or treats colorectal cancer.

Insufficient Reliable Evidence To Rate Contrast induced nephropathy
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial for preventing contrast induced nephropathy.

Insufficient Reliable Evidence To Rate Coronary artery bypass graft (CABG) surgery
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial following CABG surgery.

Insufficient Reliable Evidence To Rate Coronavirus disease 2019 (COVID-19)
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial for reducing symptoms in patients hospitalized with COVID-19.

Insufficient Reliable Evidence To Rate Crohn disease
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial for reducing the risk of Crohn disease or the risk for relapse in patients with Crohn disease who are in remission; the available evidence is conflicting.

Insufficient Reliable Evidence To Rate Cyclosporine-induced hypertension
Rating & evidence shown verbatim from Natural Medicines

Small clinical studies suggest that oral fish oil may prevent or modestly improve symptoms in patients with cyclosporine-induced hypertension.

Insufficient Reliable Evidence To Rate Cystic fibrosis
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial in patients with cystic fibrosis.

Insufficient Reliable Evidence To Rate Dementia
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil, as supplements or in the diet, reduces the risk of dementia; the available research is conflicting.

Insufficient Reliable Evidence To Rate Developmental coordination disorder (DCD)
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil has only been evaluated in combination with other ingredients; its effect when used alone is unclear.

Insufficient Reliable Evidence To Rate Diabetic nephropathy
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial in patients with diabetic nephropathy.

Insufficient Reliable Evidence To Rate Diabetic neuropathy
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial for the treatment or prevention of neuropathy in patients with type 1 diabetes.

Insufficient Reliable Evidence To Rate Diabetic retinopathy
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial in patients with diabetic retinopathy.

Insufficient Reliable Evidence To Rate Dry eye
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil does not seem to reduce the risk of developing dry eye. It is unclear if oral fish oil is beneficial in patients with existing dry eye.

Insufficient Reliable Evidence To Rate Dyslexia
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial in patients with dyslexia.

Insufficient Reliable Evidence To Rate Dyslipidemia
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial in patients with dyslipidemia.

Insufficient Reliable Evidence To Rate Endometrial cancer
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil reduces the risk for endometrial cancer.

Insufficient Reliable Evidence To Rate Endometriosis
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial in patients with endometriosis.

Insufficient Reliable Evidence To Rate Epilepsy
Rating & evidence shown verbatim from Natural Medicines

Some clinical research suggests that oral omega-3 fatty acids may modestly reduce seizure frequency in patients with epilepsy. However, it is unclear if oral fish oil itself is beneficial in patients with epilepsy.

Insufficient Reliable Evidence To Rate Exercise-induced muscle soreness
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil reduces the severity of exercise-induced muscle soreness.

Insufficient Reliable Evidence To Rate Food allergies
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial in patients with food allergies.

Insufficient Reliable Evidence To Rate Frailty
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial for preventing frailty.

Insufficient Reliable Evidence To Rate Gingivitis
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial in patients with gingivitis.

Insufficient Reliable Evidence To Rate Glaucoma
Rating & evidence shown verbatim from Natural Medicines

Although there has been interest in using oral fish oil for glaucoma, there is insufficient reliable information about the clinical effects of fish oil for this condition.

Insufficient Reliable Evidence To Rate Heart transplant
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial in patients after a heart transplant.

Insufficient Reliable Evidence To Rate Hemodialysis graft dysfunction
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial in patients with hemodialysis graft dysfunction.

Insufficient Reliable Evidence To Rate HIV/AIDS
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial for HIV.

Insufficient Reliable Evidence To Rate Impaired glucose tolerance (prediabetes)
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial for impaired glucose tolerance.

Insufficient Reliable Evidence To Rate Infant development
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil, taken during pregnancy or by the infant, is beneficial for improving vision or cognitive development in infants.

Insufficient Reliable Evidence To Rate Insomnia
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial for insomnia.

Insufficient Reliable Evidence To Rate Intrauterine growth restriction (IUGR)
Rating & evidence shown verbatim from Natural Medicines

Although there has been interest in using oral fish oil for prevention of IUGR, there is insufficient reliable information about the clinical effects of fish oil for this condition.

Insufficient Reliable Evidence To Rate Joint pain
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil has only been evaluated in combination with other ingredients; its effects when used alone are unclear.

Insufficient Reliable Evidence To Rate Kidney failure
Rating & evidence shown verbatim from Natural Medicines

Small clinical studies in patients with kidney failure suggest that oral fish oil may modestly improve some blood lipid and inflammatory marker levels.

Insufficient Reliable Evidence To Rate Kidney stones (nephrolithiasis)
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial for preventing kidney stones.

Insufficient Reliable Evidence To Rate Kidney transplant-related bone loss
Rating & evidence shown verbatim from Natural Medicines

Clinical research suggests that oral fish oil does not improve bone mineral density following a kidney transplant.

Insufficient Reliable Evidence To Rate Lung cancer
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil can improve nutritional status in patients with lung cancer.

Insufficient Reliable Evidence To Rate Lyme disease
Rating & evidence shown verbatim from Natural Medicines

Although there has been interest in using oral fish oil for Lyme disease, there is insufficient reliable information about the clinical effects of fish oil for this condition.

Insufficient Reliable Evidence To Rate Male infertility
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial for male infertility.

Insufficient Reliable Evidence To Rate Melanoma
Rating & evidence shown verbatim from Natural Medicines

It is unclear if there is a link between fish oil intake and the incidence of melanoma.

Insufficient Reliable Evidence To Rate Menopausal symptoms
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial for menopausal symptoms.

Insufficient Reliable Evidence To Rate Migraine headache
Rating & evidence shown verbatim from Natural Medicines

It is unclear if supplemental fish oil is beneficial for reducing the frequency or severity of migraine headaches. However, dietary fish oil may reduce the frequency and duration of migraine headaches.

Insufficient Reliable Evidence To Rate Muscle strength
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial for improving muscle strength in young adults.

Insufficient Reliable Evidence To Rate Obesity
Rating & evidence shown verbatim from Natural Medicines

Most clinical research shows that fish oil supplements do not improve weight loss; however, dietary fish intake might be beneficial for obesity. Clinical research also shows that taking fish oil during pregnancy does not seem to prevent overweight or obesity in the infant. It is unclear if fish oil is beneficial for improving cardiometabolic risk factors in overweight or obese children.

Insufficient Reliable Evidence To Rate Oral mucositis
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial for oral mucositis.

Insufficient Reliable Evidence To Rate Osteoporosis
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil has predominantly been evaluated in combination with other ingredients; its effect when used alone is unclear.

Insufficient Reliable Evidence To Rate Parkinson disease
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial for the treatment or prevention of Parkinson disease.

Insufficient Reliable Evidence To Rate Periodontitis
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial for periodontitis.

Insufficient Reliable Evidence To Rate Peripheral arterial disease (PAD)
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial for PAD.

Insufficient Reliable Evidence To Rate Phenylketonuria (PKU)
Rating & evidence shown verbatim from Natural Medicines

Small clinical studies suggest that oral fish oil may modestly improve symptoms in patients with PKU.

Insufficient Reliable Evidence To Rate Pneumonia
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial for pneumonia.

Insufficient Reliable Evidence To Rate Polycystic ovary syndrome (PCOS)
Rating & evidence shown verbatim from Natural Medicines

Most small clinical studies suggest that oral fish oil is not beneficial for weight loss or glucose homeostasis in patients with PCOS.

Insufficient Reliable Evidence To Rate Polymyalgia rheumatica
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial for polymyalgia rheumatica prevention.

Insufficient Reliable Evidence To Rate Post-traumatic stress disorder (PTSD)
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial for PTSD.

Insufficient Reliable Evidence To Rate Postmenopausal conditions
Rating & evidence shown verbatim from Natural Medicines

Most research shows that oral fish oil is beneficial for improving triglyceride levels after menopause. More research is needed to determine the optimal dose and duration.

Insufficient Reliable Evidence To Rate Postoperative fistula
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil has only been evaluated in combination with other ingredients; its effect when used alone is unclear.

Insufficient Reliable Evidence To Rate Postoperative infection
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil has only been evaluated in combination with other ingredients; its effect when used alone is unclear.

Insufficient Reliable Evidence To Rate Postoperative recovery
Rating & evidence shown verbatim from Natural Medicines

Oral fish oil has only been evaluated in combination with other ingredients; its effect when used alone is unclear.

Insufficient Reliable Evidence To Rate Postpartum depression
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial for postpartum depression.

Insufficient Reliable Evidence To Rate Prematurity
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial for improving the development of premature infants.

Insufficient Reliable Evidence To Rate Pressure ulcers
Rating & evidence shown verbatim from Natural Medicines

It is unclear if enteral or topical fish oil is beneficial in patients with pressure ulcers.

Insufficient Reliable Evidence To Rate Preterm labor
Rating & evidence shown verbatim from Natural Medicines

Research on the use of oral fish oil for the prevention of preterm labor is conflicting; however, there may be benefit of oral fish oil in patients with low baseline omega-3 status.

Insufficient Reliable Evidence To Rate Prostate cancer
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial for improving quality of life in patients with prostate cancer undergoing a prostatectomy.

Insufficient Reliable Evidence To Rate Pruritus
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial in patients with pruritus.

Insufficient Reliable Evidence To Rate Psoriasis
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral or topical fish oil is beneficial for the treatment or prevention of psoriasis. Intravenous fish oil seems to reduce symptoms in patients with acute, extended guttate psoriasis or chronic plaque psoriasis.

Insufficient Reliable Evidence To Rate Raynaud syndrome
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial in patients with this condition.

Insufficient Reliable Evidence To Rate Salicylate intolerance
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial in patients with salicylate intolerance.

Insufficient Reliable Evidence To Rate Sarcopenia
Rating & evidence shown verbatim from Natural Medicines

There is conflicting evidence as to whether oral fish oil improves muscle strength in adults with sarcopenia.

Insufficient Reliable Evidence To Rate Schizophrenia
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial in patients with schizophrenia.

Insufficient Reliable Evidence To Rate Sepsis
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial in patients with sepsis.

Insufficient Reliable Evidence To Rate Sickle cell disease
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial in patients with sickle cell disease.

Insufficient Reliable Evidence To Rate Stroke
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial in the secondary prevention of stroke or for improving recovery from a stroke. Oral supplemental fish oil does not seem to be beneficial in the primary prevention of stroke.

Insufficient Reliable Evidence To Rate Systemic lupus erythematosus (SLE)
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial for the treatment or prevention of SLE.

Insufficient Reliable Evidence To Rate Tinnitus
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial in the prevention of tinnitus.

Insufficient Reliable Evidence To Rate Ulcerative colitis
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial in patients with ulcerative colitis.

Insufficient Reliable Evidence To Rate Upper respiratory tract infection (URTI)
Rating & evidence shown verbatim from Natural Medicines

It is unclear if oral fish oil is beneficial for URTI prevention or treatment.

Insufficient Reliable Evidence To Rate Venous thromboembolism (VTE)
Rating & evidence shown verbatim from Natural Medicines

It is unclear if dietary fish or omega-3 fatty acids are beneficial in VTE prevention.

Insufficient Reliable Evidence To Rate Vitamin D deficiency
Rating & evidence shown verbatim from Natural Medicines

It is unclear if fish oil is beneficial for vitamin D deficiency.

Source & disclaimer. Effectiveness ratings and evidence summaries are provided by Natural Medicines (Therapeutic Research Center) and shown as licensed. Where Natural Medicines hasn’t rated a use, HelloPharmacist’s pharmacists may add their own reviewed rating and evidence (each such entry is labeled). This is educational information, not medical advice — talk with your pharmacist or doctor before starting, stopping, or changing a supplement.

Safety & precautions

Fish oil is generally considered safe for most adults when taken at typical supplement doses. People who should be more cautious include those with a fish or shellfish allergy, those with bleeding disorders, and anyone scheduled for surgery, since high doses may affect bleeding.

If you take blood-thinning medicines or have a medical condition, check with your pharmacist or doctor before starting fish oil. Choose products that are tested for purity, since some fish can contain contaminants like mercury (high-quality supplements usually remove these).

For pregnancy and breastfeeding, omega-3s are often recommended as part of a healthy diet, and DHA is important for fetal development. However, supplement use should be guided by your doctor, and you should avoid fish high in mercury. Because product strengths vary, use only under professional guidance during these times.

Side effects

The most common side effects are mild and digestive, such as a fishy aftertaste, fishy breath or burps, nausea, loose stools, and heartburn. Taking it with food or using enteric-coated products may reduce these effects.

At higher doses, fish oil may slightly increase the risk of bleeding or bruising. Some research has linked very high omega-3 intake to a small increased chance of a heart rhythm problem called atrial fibrillation. Serious allergic reactions are rare but possible in people allergic to fish.

Fish Oil: Reported Adverse Effects

Documented safety reports on Fish Oil from the evidence-graded Natural Medicines (TRC Healthcare) database, shown word-for-word from the licensed record.

Orally and parenterally, fish oil is generally well-tolerated. Topically, no adverse effects have been reported. However, a thorough evaluation of safety outcomes has not been conducted.

Most Common Adverse Effects:

Orally: Abdominal pain, bad breath, fishy aftertaste, heartburn, increased low-density lipoprotein (LDL) cholesterol levels, loose stools, nausea, and rash.

Serious Adverse Effects (Rare):

Orally: Atrial fibrillation. When taken in doses of 3 grams or more daily, there are rare reports of increased risk of bleeding and stroke, as well as immune suppression.

Reports by condition
Allergic rhinitis (hay fever) Immunologic

A case of anaphylaxis following ingestion of a fish oil capsule has been reported for a female patient with a history of allergy to crab. The patient was treated successfully with epinephrine, but had several recurrences of stridor over the next 2 days.

There is also some evidence that fish oil in doses greater than 3 grams per day might adversely affect immune function. Fish oil appears to suppress T- and B-cell function and to reduce the production of cytokines, which might be detrimental to elderly people and people with suppressed immune function such as patients with human immunodeficiency virus (HIV) infection.

  1. Kmet A, Unger J, Jahangir K, Kolber MR. Fish-oil capsule ingestion: a case of recurrent anaphylaxis. Can Fam Physician 2012;58(7):e379-81.
  2. FDA. Center for Food Safety and Applied Nutrition. Letter regarding dietary supplement health claim for omega-3 fatty acids and coronary heart disease. Available at: http://www.fda.gov/ohrms/dockets/dockets/95s0316/95s-0316-Rpt0272-38-Appendix-D-Reference
  3. Kelley DS, Rudolph IL. Effect of individual fatty acids of omega-6 and omega-3 type on human immune status and role of eicosanoids. Nutrition 2000;16:143-5.
  4. Meydani SN, Dinarello CA. Influence of dietary fatty acids on cytokine production and its clinical implications. Nutr Clin Pract 1993;8:65-72.
Anemia Hematologic

Orally, 3 grams or greater of omega-3 fatty acids daily may inhibit platelet aggregation and increase the risk of bleeding; however, there is little evidence of statistically significant bleeding risk at lower doses. Very large intakes of fish oil or omega-3 fatty acids (more than 46 grams per day) may increase the risk of ischemic or hemorrhagic (bleeding) stroke.

A case of hemolytic anemia has been reported for an infant with short bowel syndrome who developed liver disease from total parenteral nutrition (TPN) and was switched to a specific TPN with fish oil (Omegaven, Fresenius-Kabi, Graz, Austria) instead. After stopping the fish oil-TPN, the anemia was reversed suggesting that parenteral fish oil might cause hemolytic anemia.

  1. FDA. Center for Food Safety and Applied Nutrition. Letter regarding dietary supplement health claim for omega-3 fatty acids and coronary heart disease. Available at: http://www.fda.gov/ohrms/dockets/dockets/95s0316/95s-0316-Rpt0272-38-Appendix-D-Reference
  2. Pedersen HS, Mulvad G, Seidelin KN, et al. N-3 fatty acids as a risk factor for haemorrhagic stroke. Lancet 1999;353:812-3.
  3. Knapp, H. R. Dietary fatty acids in human thrombosis and hemostasis. Am J Clin Nutr 1997;65(5 Suppl):1687S-1698S.
  4. Archer, S. L., Green, D., Chamberlain, M., Dyer, A. R., and Liu, K. Association of dietary fish and n-3 fatty acid intake with hemostatic factors in the coronary artery risk development in young adults (CARDIA) study. Arterioscler Thromb.Vasc.Biol 1998;1
  5. Weksler, B. B. Omega 3 fatty acids have multiple antithrombotic effects. World Rev Nutr Diet 1994;76:47-50.
  6. McNamara RK, Strawn JR, Tallman MJ, et al. Effects of fish oil monotherapy on depression and prefrontal neurochemistry in adolescents at high risk for bipolar I disorder: A 12-week placebo-controlled proton magnetic resonance spectroscopy trial. J Child A
  7. Caicoya M. Fish consumption and stroke: a community case-control study in Asturias, Spain. Neuroepidemiology 2002;21:107-14.
  8. Kromann, N. and Green, A. Epidemiological studies in the Upernavik district, Greenland. Incidence of some chronic diseases 1950-1974. Acta Med Scand 1980;208(5):401-406.
  9. Mallah, H. S., Brown, M. R., Rossi, T. M., and Block, R. C. Parenteral fish oil-associated burr cell anemia. J Pediatr 2010;156(2):324-326.
Anorexia Gastrointestinal

Orally, most adverse effects of omega-3 fatty acids are gastrointestinal in nature. Gastrointestinal upset is common with the use of fish oil supplements, occurring in up to 5% of patients in clinical trials, with nausea in up to 1.5% of patients. Diarrhea and loose stools may also occur, with potentially severe diarrhea at very high doses. There have also been reports of increased burping, acid reflux, heartburn, indigestion, abdominal bloating, abdominal or gastrointestinal pain or discomfort, anorexia, flatulence, constipation, nausea and vomiting, steatorrhea, fishy hiccups, metallic taste, and a fishy breath odor and aftertaste. Also, some preliminary evidence suggests that increased serum levels of omega-3 fatty acids, especially DHA, might increase the risk for atrophic gastritis.

Gastrointestinal side effects may be minimized if fish oils are taken with meals and if doses are started low and gradually increased. Taking supplements with meals or freezing them seems to help decrease these side effects for some patients. Enteric coated fish products might also help reduce side effects.

  1. Wang C, Chung M, Lichtenstein A, et al. Effects of omega-3 fatty acids on cardiovascular disease. Evid Rep Technol Assess (Summ) 2004 Mar;(94):1-8.
  2. Maclean, C. H., Mojica, W. A., Morton, S. C., Pencharz, J., Hasenfeld, Garland R., Tu, W., Newberry, S. J., Jungvig, L. K., Grossman, J., Khanna, P., Rhodes, S., and Shekelle, P. Effects of omega-3 fatty acids on lipids and glycemic control in type II di
  3. Reisman, J., Schachter, H. M., Dales, R. E., Tran, K., Kourad, K., Barnes, D., Sampson, M., Morrison, A., Gaboury, I., and Blackman, J. Treating asthma with omega-3 fatty acids: where is the evidence? A systematic review. BMC.Complement Altern Med 2006;6
  4. Lim, A. K., Manley, K. J., Roberts, M. A., and Fraenkel, M. B. Fish oil for kidney transplant recipients. Cochrane Database Syst Rev 2007;(2):CD005282.
  5. Freund-Levi, Y., Basun, H., Cederholm, T., Faxen-Irving, G., Garlind, A., Grut, M., Vedin, I., Palmblad, J., Wahlund, L. O., and Eriksdotter-Jonhagen, M. Omega-3 supplementation in mild to moderate Alzheimer's disease: effects on neuropsychiatric symptom
  6. Turnbull, T., Cullen-Drill, M., and Smaldone, A. Efficacy of omega-3 fatty acid supplementation on improvement of bipolar symptoms: a systematic review. Arch Psychiatr.Nurs 2008;22(5):305-311.
  7. Turner, D., Shah, P. S., Steinhart, A. H., Zlotkin, S., and Griffiths, A. M. Maintenance of remission in inflammatory bowel disease using omega-3 fatty acids (fish oil): a systematic review and meta-analyses. Inflamm.Bowel.Dis. 2011;17(1):336-345.
  8. Mills, S. C., von Roon, A. C., Tekkis, P. P., and Orchard, T. R. Crohn's disease. Clin.Evid.(Online.) 2011;2011
  9. Martinez-Victoria, E. and Yago, M. D. Omega 3 polyunsaturated fatty acids and body weight. Br.J.Nutr. 2012;107 Suppl 2:S107-S116.
  10. Schachter, HM, Reisman, J, Tran, K, Dales, B, Kourad, K, Barnes, D, Sampson, M, Morrison, A, Gaboury, I, and Blackman, J. Health effects of omega-3 fatty acids on asthma. Evid.Rep.Technol.Assess.(Summ.) 2004;(91):1-7.
  11. Lev-Tzion R, Griffiths AM, Leder O, Turner D. Omega 3 fatty acids (fish oil) for maintenance of remission in Crohn's disease. Cochrane Database Syst Rev 2014;2:CD006320.
  12. Nigam A1, Talajic M, Roy D, Nattel S, Lambert J, Nozza A, Jones P, Ramprasath VR, O'Hara G, Kopecky S, Brophy JM, Tardif JC; AFFORD Investigators. Fish oil for the reduction of atrial fibrillation recurrence, inflammation, and oxidative stress. J Am Coll
  13. Nicholls SJ, Lincoff AM, Garcia M, et al. Effect of high-dose omega-3 fatty acids vs corn oil on major adverse cardiovascular events in patients at high cardiovascular risk: The STRENGTH randomized clinical trial. JAMA. 2020e2022258.
  14. Riddell JK, Malin AJ, Flora D, McCague H, Till C. Association of water fluoride and urinary fluoride concentrations with attention deficit hyperactivity disorder in Canadian youth. Environ Int. 2019;133(Pt B):105190.
  15. Elsadek AE, Maksoud YHA, Suliman HA, et al. Omega-3 supplementation in children with ADHD and intractable epilepsy. J Clin Neurosci 2021;94:237-243.
  16. Wang HF, Liu WC, Zailani H, et al. A 12-week randomized double-blind clinical trial of eicosapentaenoic acid intervention in episodic migraine. Brain Behav Immun 2024;118:459-467.
  17. Anon. Dietary supplementation with n-3 polyunsaturated fatty acids and vitamin E after myocardial infarction: results of the GISSI-Prevenzione trial. Gruppo Italiano per lo Studio della Soprawivenza nell'Infarto miocardico. Lancet 1999;354:447-55.
  18. Gissi-HF Investigators; Tavazzi L, Maggioni AP, Marchioli R, et al. Effect of n-3 polyunsaturated fatty acids in patients with chronic heart failure (the GISSI-HF trial): a randomised, double-blind, placebo-controlled trial. Lancet 2008;372:1223-30.
  19. Amminger, G. P., Berger, G. E., Schafer, M. R., Klier, C., Friedrich, M. H., and Feucht, M. Omega-3 fatty acids supplementation in children with autism: a double-blind randomized, placebo-controlled pilot study. Biol.Psychiatry 2-15-2007;61(4):551-553.
  20. Bowden, R. G., Wilson, R. L., Gentile, M., Ounpraseuth, S., Moore, P., and Leutholtz, B. C. Effects of omega-3 fatty acid supplementation on vascular access thrombosis in polytetrafluorethylene grafts. J Ren Nutr 2007;17(2):126-131.
  21. Freeman, M. P., Davis, M., Sinha, P., Wisner, K. L., Hibbeln, J. R., and Gelenberg, A. J. Omega-3 fatty acids and supportive psychotherapy for perinatal depression: a randomized placebo-controlled study. J.Affect.Disord. 2008;110(1-2):142-148.
  22. van de Rest, O., Geleijnse, J. M., Kok, F. J., van Staveren, W. A., Dullemeijer, C., Olderikkert, M. G., Beekman, A. T., and de Groot, C. P. Effect of fish oil on cognitive performance in older subjects: a randomized, controlled trial. Neurology 8-5-2008
  23. Lucas, M., Asselin, G., Merette, C., Poulin, M. J., and Dodin, S. Ethyl-eicosapentaenoic acid for the treatment of psychological distress and depressive symptoms in middle-aged women: a double-blind, placebo-controlled, randomized clinical trial. Am.J.Cl
  24. van de Rest, O., Geleijnse, J. M., Kok, F. J., van Staveren, W. A., Olderikkert, M. G., Beekman, A. T., and de Groot, L. C. Effect of fish oil supplementation on quality of life in a general population of older Dutch subjects: a randomized, double-blind,
  25. Harper, M., Thom, E., Klebanoff, M. A., Thorp, J., Jr., Sorokin, Y., Varner, M. W., Wapner, R. J., Caritis, S. N., Iams, J. D., Carpenter, M. W., Peaceman, A. M., Mercer, B. M., Sciscione, A., Rouse, D. J., Ramin, S. M., and Anderson, G. D. Omega-3 fatty
  26. Bahadori, B., Uitz, E., Thonhofer, R., Trummer, M., Pestemer-Lach, I., McCarty, M., and Krejs, G. J. omega-3 Fatty acids infusions as adjuvant therapy in rheumatoid arthritis. JPEN J Parenter.Enteral Nutr 2010;34(2):151-155.
  27. Salomon, P., Kornbluth, A. A., and Janowitz, H. D. Treatment of ulcerative colitis with fish oil n--3-omega-fatty acid: an open trial. J Clin Gastroenterol 1990;12(2):157-161.
  28. van der Meij, B. S., van Bokhorst-de van der Schueren MA, Langius, J. A., Brouwer, I. A., and van Leeuwen, P. A. n-3 PUFAs in cancer, surgery, and critical care: a systematic review on clinical effects, incorporation, and washout of oral or enteral compa
  29. Delgado-Lista, J., Perez-Martinez, P., Lopez-Miranda, J., and Perez-Jimenez, F. Long chain omega-3 fatty acids and cardiovascular disease: a systematic review. Br.J.Nutr. 2012;107 Suppl 2:S201-S213.
  30. Appel, L. J., Miller, E. R., III, Seidler, A. J., and Whelton, P. K. Does supplementation of diet with 'fish oil' reduce blood pressure? A meta-analysis of controlled clinical trials. Arch Intern Med 6-28-1993;153(12):1429-1438.
  31. Contacos, C., Barter, P. J., and Sullivan, D. R. Effect of pravastatin and omega-3 fatty acids on plasma lipids and lipoproteins in patients with combined hyperlipidemia. Arterioscler.Thromb. 1993;13(12):1755-1762.
  32. Deutch B, Jorgensen EB, and Hansen JC. Menstrual discomfort in Danish women reduced by dietary supplements of omega-3 PUFA and B12 (fish oil or seal oil capsules). Nutr Res 2000;20(5):621-631.
  33. Kuenzel U and Bertsch S. Clinical experiences with a standardized commercial fish oil product containing 33.5% omega-3 fatty acids - field trial with 3958 hyperlipemic patients in general practitioner practice. In: Chandra RK. Health Effects of Fish and F
  34. Suradom C, Suttajit S, Oon-Arom A, Maneeton B, Srisurapanont M. Omega-3 polyunsaturated fatty acid (n-3 PUFA) supplementation for prevention and treatment of perinatal depression: a systematic review and meta-analysis of randomized-controlled trials. Nord
  35. Moussa H, Robitaille K, Pelletier JF, et al. Effects of concentrated long-chain omega-3 polyunsaturated fatty acid supplementation on quality of life after radical prostatectomy: A phase II randomized placebo-controlled trial (RCT-EPA). Nutrients 2023;15(
  36. Belluzzi A, Brignola C, Campieri M, et al. Effect of an enteric-coated fish-oil preparation on relapses in Crohn's disease. N Engl J Med 1996;334:1557-60.
  37. Su KP, Huang SY, Chiu CC, Shen WW. Omega-3 fatty acids in major depressive disorder. A preliminary double-blind, placebo-controlled trial. Eur Neuropsychopharmacol 2003;13:267-71..
  38. Schachter, H. M., Kourad, K., Merali, Z., Lumb, A., Tran, K., and Miguelez, M. Effects of omega-3 fatty acids on mental health. Evid.Rep.Technol.Assess.(Summ.) 2005;(116):1-11.
  39. Buydens-Branch, Branchey, M., and Hibbeln, J. R. Low plasma levels of docosahexaenoic acid are associated with an increased relapse vulnerability in substance abusers. Am J Addict. 2009;18(1):73-80.
  40. Oliver, C. and Jahnke, N. Omega-3 fatty acids for cystic fibrosis. Cochrane.Database.Syst.Rev. 2011;(8):CD002201.
  41. Cabre, E., Manosa, M., and Gassull, M. A. Omega-3 fatty acids and inflammatory bowel diseases - a systematic review. Br.J.Nutr. 2012;107 Suppl 2:S240-S252.
  42. Sydenham E, Dangour AD Lim WS. Omega 3 fatty acid for the prevention of cognitive decline and dementia. Cochrane Database Syst Rev. 2012;6:CD005379.
  43. Oliveira JM, Rondó PH, Yudkin JS, Souza JM, Pereira TN, Catalani AW, Picone CM, Segurado AA. Effects of fish oil on lipid profile and other metabolic outcomes in HIV-infected patients on antiretroviral therapy: a randomized placebo-controlled trial. Int J
  44. Raitt MH, Connor WE, Morris C, et al. Fish oil supplementation and risk of ventricular tachycardia and ventricular fibrillation in patients with implantable defibrillators: a randomized controlled trial. JAMA 2005;293:2884-91.
  45. Lucas M, Asselin G, Merette C, et al. Effects of ethyl-eicosapentaenoic acid omega-3 fatty acid supplementation on hot flashes and quality of life among middle-aged women: a double-blind, placebo-controlled, randomized clinical trial. Menopause 2009;16:3
  46. Glaum, M., Metzelthin, E., Junker, S., Luley, C., and Klor, H. U. [Comparative effect of oral fat loads with saturated, omega-6 and omega- 3 fatty acids before and after fish oil capsule therapy in healthy probands]. Klin.Wochenschr 1990;68 Suppl 22:103-
  47. Henderson, W. R., Jr., Astley, S. J., McCready, M. M., Kushmerick, P., Casey, S., Becker, J. W., and Ramsey, B. W. Oral absorption of omega-3 fatty acids in patients with cystic fibrosis who have pancreatic insufficiency and in healthy control subjects.
  48. Holland S, Silberstein SD, Freitag F, et al. Evidence-based guideline update: NSAIDs and other complementary treatments for episodic migraine prevention in adults: Report of the Quality Standards Subcommittee of the American Academy of Neurology and the A
  49. Caniato, R. N., Alvarenga, M. E., and Garcia-Alcaraz, M. A. Effect of omega-3 fatty acids on the lipid profile of patients taking clozapine. Aust N Z J Psychiatry 2006;40(8):691-697.
  50. Ng, R. C., Hirata, C. K., Yeung, W., Haller, E., and Finley, P. R. Pharmacologic treatment for postpartum depression: a systematic review. Pharmacotherapy 2010;30(9):928-941.
  51. Satokar VV, Derraik JGB, Harwood M, et al. Fish oil supplementation during pregnancy and postpartum in mothers with overweight and obesity to improve body composition and metabolic health during infancy: A double-blind randomized controlled trial. Am J Cl
  52. Cobiac, L., Nestel, P. J., Wing, L. M., and Howe, P. R. A low-sodium diet supplemented with fish oil lowers blood pressure in the elderly. J Hypertens. 1992;10(1):87-92.
  53. Maresta A, Balduccelli M, Varani E, et al. Prevention of postcoronary angioplasty restenosis by omega-3 fatty acids: main results of the Esapent for Prevention of Restenosis Italian Study (ESPRIT). Am Heart J 143:E5.
  54. Armaganijan L, Lopes RD, Healey JS, et al. Do omega-3 fatty acids prevent atrial fibrillation after open heart surgery? A meta-analysis of randomized controlled trials. Clinics (Sao Paulo) 2011;66:1923-8.
  55. Persson, C., Glimelius, B., Ronnelid, J., and Nygren, P. Impact of fish oil and melatonin on cachexia in patients with advanced gastrointestinal cancer: a randomized pilot study. Nutrition 2005;21(2):170-178.
  56. Lawrence, R. and Sorrell, T. Eicosapentaenoic acid in cystic fibrosis: evidence of a pathogenetic role for leukotriene B4. Lancet 8-21-1993;342(8869):465-469.
  57. Tur, J. A., Bibiloni, M. M., Sureda, A., and Pons, A. Dietary sources of omega 3 fatty acids: public health risks and benefits. Br.J.Nutr. 2012;107 Suppl 2:S23-S52.
  58. Loeschke, K., Ueberschaer, B., Pietsch, A., Gruber, E., Ewe, K., Wiebecke, B., Heldwein, W., and Lorenz, R. n-3 fatty acids only delay early relapse of ulcerative colitis in remission. Dig.Dis.Sci. 1996;41(10):2087-2094.
  59. Souied EH, Delcourt C, Querques G, Bassols A, Merle B, Zourdani A, Smith T, Benlian P; Nutritional AMD Treatment 2 Study Group. Oral docosahexaenoic acid in the prevention of exudative age-related macular degeneration: the Nutritional AMD Treatment 2 stud
  60. Ito Y, Suzuki K, Imai H, et al. Effects of polyunsaturated fatty acids on atrophic gastritis in a Japanese population. Cancer Lett 2001;163:171-8.
  61. Harris WS. Fish oil supplementation: evidence for health benefits. Cleve Clin J Med 2004;71:208-10, 212, 215-8 passim.
  62. Belluzzi A, Brignola C, Campieri M, et al. Effects of new fish oil derivative on fatty acid phospholipid-membrane pattern in a group of Crohn's disease patients. Dig Dis Sci 1994;39:2589-94.
Asthma Pulmonary/Respiratory

Orally, fish oil has been reported to cause nasopharyngitis and upper respiratory tract infections in 3.3% of patients in one clinical trial. Exacerbation of asthma and apnea have been reported for patients using fish oil.

  1. Davidson, M. H., Stein, E. A., Bays, H. E., Maki, K. C., Doyle, R. T., Shalwitz, R. A., Ballantyne, C. M., and Ginsberg, H. N. Efficacy and tolerability of adding prescription omega-3 fatty acids 4 g/d to simvastatin 40 mg/d in hypertriglyceridemic patie
  2. Hawthorne AB, Daneshmend TK, Hawkey CJ, et al. Treatment of ulcerative colitis with fish oil supplementation: a prospective 12 month randomised controlled trial. Gut 1992;33:922-8.
  3. Turner, D., Shah, P. S., Steinhart, A. H., Zlotkin, S., and Griffiths, A. M. Maintenance of remission in inflammatory bowel disease using omega-3 fatty acids (fish oil): a systematic review and meta-analyses. Inflamm.Bowel.Dis. 2011;17(1):336-345.
  4. Oliver, C. and Jahnke, N. Omega-3 fatty acids for cystic fibrosis. Cochrane.Database.Syst.Rev. 2011;(8):CD002201.
  5. Lawrence, R. and Sorrell, T. Eicosapentaenoic acid in cystic fibrosis: evidence of a pathogenetic role for leukotriene B4. Lancet 8-21-1993;342(8869):465-469.
Atherosclerosis Cardiovascular

Orally, fish oil supplements in doses of 3-10 grams daily can cause a dose-dependent increase in low-density lipoprotein (LDL) cholesterol levels in some people by increasing the size of LDL particles. Therefore, LDL levels should be monitored in people who take fish oil supplements. But fish oil doesn't seem to cause development of atherosclerosis, despite earlier concerns that polyunsaturated fatty acids, such as omega-3 fatty acids, might increase the oxidation of LDL.

There is concern that fish oil supplements may be associated with an increased risk for atrial fibrillation (AF). In one large clinical study (the STRENGTH trial), taking a prescription fish oil product (Epanova) 4 grams daily for up to 5 years was associated with an increased risk for AF, with a number needed to harm of 114 when compared with a corn oil control. The patients in this study were considered to be at high risk for future cardiovascular disease (CVD). Also, one large population study in adults without CVD suggests that regular use of fish oil supplements is associated with a modestly higher risk of both atrial fibrillation and stroke when compared with non-use of fish oil supplements.

In a secondary analysis of the Omega-3 fatty acids in Elderly patients with Myocardial Infarction (OMEMI) trial, adults aged 70-82 years with recent myocardial infarction supplementing with 1.8 grams daily of n-3 PUFA (EPA/DHA) for 24 months had a 90% increased risk of developing AF or micro-AF, which is characterized by short, AF-like activity lasting less than 30 seconds. Changes in serum EPA levels seem to mediate this risk, with higher serum EPA levels predictive of an increased risk of AF and intermediate serum EPA levels predictive of an increased risk of micro-AF.

Meta-analyses of randomized controlled trials show that taking omega-3 fatty acid supplements increases the incidence rate ratio for AF by up to 37% when compared with placebo, with an increased incidence rate associated with doses of more than 1 gram daily. One study in these analyses used eicosapentaenoic acid (EPA) alone as purified icosapent ethyl.

In 2023, the Pharmacovigilance Risk Assessment Committee (PRAC) of the European Medicines Agency issued a public statement on the use of omega-3-acid ethyl esters, concluding that exposure to omega-3-acid ethyl esters for the treatment of hypertriglyceridemia is associated with a dose-dependent increased risk of AF in patients with established cardiovascular disease or risk factors for cardiovascular disease when compared with placebo. The highest risk of AF is associated with a dose of 4 grams daily. If AF occurs, treatment should be permanently discontinued.

  1. Montori VM, Farmer A, Wollan PC, Dinneen SF. Fish oil supplementation in type 2 diabetes: a quantitative systemic review (abstract). Diabetes Care 2000;23:1407-15.
  2. Adler A, Holub BJ. Effect of garlic and fish-oil supplementation on serum lipid and lipoprotein concentrations in hypercholesterolemic men. Am J Clin Nutr 1997;65:445-50.
  3. Dewailly E, Blanchet C, Lemieux S, et al. n-3 Fatty acids and cardiovascular disease risk factors among the Inuit of Nunavik. Am J Clin Nutr 2001;74:464-73.
  4. Lacaille B, Julien P, Deshaies Y, et al. Responses of plasma lipoproteins and sex hormones to the consumption of lean fish incorporated in a prudent-type diet in normolipidemic men. J Am Coll Nutr 2000;19:745-53.
  5. McKenney JM, Sica D. Prescription omega-3 fatty acids for the treatment of hypertriglyceridemia. Am J Health-Syst Pharm 2007;64:595-605.
  6. Malinowski JM, Metka K. Elevation of low-density lipoprotein cholesterol concentration with over-the-counter fish oil supplementation. Ann Pharmacother 2007;41:1296-300.
  7. Sanders, T. A., Gleason, K., Griffin, B., and Miller, G. J. Influence of an algal triacylglycerol containing docosahexaenoic acid (22 : 6n-3) and docosapentaenoic acid (22 : 5n-6) on cardiovascular risk factors in healthy men and women. Br J Nutr 2006;95
  8. Caniato, R. N., Alvarenga, M. E., and Garcia-Alcaraz, M. A. Effect of omega-3 fatty acids on the lipid profile of patients taking clozapine. Aust N Z J Psychiatry 2006;40(8):691-697.
  9. Suzukawa M, Abbey M, Howe PR, Nestel PJ. Effects of fish oil fatty acids on low density lipoprotein size, oxidizability, and uptake by macrophages. J Lipid Res 1995;36:473-84..
  10. Allard JP, Kurian R, Aghdassi E, Muggli R, et al. Lipid peroxidation during n-3 fatty acid and vitamin E supplementation in humans. Lipids 1997;32:535-41..
  11. Higdon JV, Liu J, Du S, et al. Supplementation of postmenopausal women with fish oil rich in eicosapentaenoic acid and docosahexaenoic acid is not associated with greater in vivo lipid peroxidation compared with oils rich in oleate and linoleate as asses
  12. de Deckere EAM, Korver O, Verschuren PM, Katan MB. Health aspects of fish and n-3 polyunsaturated fatty acids from plant and marine origin. Eur J Clin Nutr 1998;52:749-53.
  13. Sorensen NS, Marckmann P, Hoy CE, et al. Effect of fish-oil-enriched margarine on plasma lipids, low-density-lipoprotein particle composition, size, and susceptibility to oxidation. Am J Clin Nutr 1998;68:235-41.
  14. Higgins S, McCarthy SN, Corridan BM, et al. Measurement of free cholesterol, cholesteryl esters and cholesteryl linoleate hydroperoxide in copper-oxidised low density lipoprotein in healthy volunteers supplemented with a low dose of n-3 polyunsaturated f
  15. Higdon JV, Du SH, Lee YS, et al. Supplementation of postmenopausal women with fish oil does not increase overall oxidation of LDL ex vivo compared to dietary oils rich in oleate and linoleate. J Lipid Res 2001;42:407-18.
  16. Nicholls SJ, Lincoff AM, Garcia M, et al. Effect of high-dose omega-3 fatty acids vs corn oil on major adverse cardiovascular events in patients at high cardiovascular risk: The STRENGTH randomized clinical trial. JAMA. 2020e2022258.
  17. Chen G, Qian ZM, Zhang J, et al. Regular use of fish oil supplements and course of cardiovascular diseases: prospective cohort study. BMJ Med 2024;3(1):e000451.
  18. Myhre PL, Berge T, Kalstad AA, et al. Omega-3 fatty acid supplements and risk of atrial fibrillation and 'micro-atrial fibrillation': A secondary analysis from the OMEMI trial. Clin Nutr 2023;42(9):1657-1660.
  19. Lombardi M, Carbone S, Del Buono MG, et al. Omega-3 fatty acids supplementation and risk of atrial fibrillation: an updated meta-analysis of randomized controlled trials. Eur Heart J Cardiovasc Pharmacother 2021;7(4):e69-e70.
  20. Gencer B, Djousse L, Al-Ramady OT, Cook NR, Manson JE, Albert CM. Effect of long-term marine ɷ-3 fatty acids supplementation on the risk of atrial fibrillation in randomized controlled trials of cardiovascular outcomes: A systematic review and meta-a
  21. Khan SU, Lone AN, Khan MS, et al. Effect of omega-3 fatty acids on cardiovascular outcomes: A systematic review and meta-analysis. EClinicalMedicine 2021;38:100997.
  22. European Medicines Agency. Meeting highlights from the Pharmacovigilance Risk Assessment Committee (PRAC) 25-28 September 2023. September 29, 2023. Available at: https://www.ema.europa.eu/en/news/meeting-highlights-pharmacovigilance-risk-assessment-commit
Breast cancer Oncologic

There is some concern that high fish intake may increase the risk for certain types of cancer. One large epidemiological study has found that dietary intake of fish oil from fatty fish twice a week or more is associated with a 16% increased risk of breast cancer when compared with eating fatty fish less than twice weekly. Additionally, an analysis of the NIH-AARP Diet and Health Study, a prospective cohort study in over 491,000 older adults, has found that total intake of fish is associated with increased melanoma risk over a median follow-up of 15.5 years. When the lowest and highest quintiles of intake are compared, there is a 22% increase in the risk for malignant melanoma and a 28% increase in the risk for melanoma in situ. In sub-group analyses, all melanoma incidence is positively associated with tuna intake or non-fried fish intake, but malignant melanoma incidence is inversely associated with fried fish intake. It was suggested that the positive associations could be due to contaminants in fish such as polychlorinated biphenyls, dioxins, arsenic, and mercury.

  1. Liu Z, Luo Y, Ren J, et al. Association between fish oil supplementation and cancer risk according to fatty fish consumption: A large prospective population-based cohort study using UK Biobank. Int J Cancer 2022;150(4):562-571.
  2. Li Y, Liao LM, Sinha R, et al. Fish intake and risk of melanoma in the NIH-AARP diet and health study. Cancer Causes Control. 2022;33(7):921-8.
Cluster headache Neurologic/CNS

Orally, fish oil may cause headache, dizziness, and inability to sleep. Also, restlessness and formication have been reported in less than 1% of studied cases of patients taking fish oil.

  1. Maclean, C. H., Mojica, W. A., Morton, S. C., Pencharz, J., Hasenfeld, Garland R., Tu, W., Newberry, S. J., Jungvig, L. K., Grossman, J., Khanna, P., Rhodes, S., and Shekelle, P. Effects of omega-3 fatty acids on lipids and glycemic control in type II di
  2. Schachter, H. M., Kourad, K., Merali, Z., Lumb, A., Tran, K., and Miguelez, M. Effects of omega-3 fatty acids on mental health. Evid.Rep.Technol.Assess.(Summ.) 2005;(116):1-11.
  3. Oliveira JM, Rondó PH, Yudkin JS, Souza JM, Pereira TN, Catalani AW, Picone CM, Segurado AA. Effects of fish oil on lipid profile and other metabolic outcomes in HIV-infected patients on antiretroviral therapy: a randomized placebo-controlled trial. Int J
  4. Nicholls SJ, Lincoff AM, Garcia M, et al. Effect of high-dose omega-3 fatty acids vs corn oil on major adverse cardiovascular events in patients at high cardiovascular risk: The STRENGTH randomized clinical trial. JAMA. 2020e2022258.
  5. Suradom C, Suttajit S, Oon-Arom A, Maneeton B, Srisurapanont M. Omega-3 polyunsaturated fatty acid (n-3 PUFA) supplementation for prevention and treatment of perinatal depression: a systematic review and meta-analysis of randomized-controlled trials. Nord
  6. Kuenzel U and Bertsch S. Clinical experiences with a standardized commercial fish oil product containing 33.5% omega-3 fatty acids - field trial with 3958 hyperlipemic patients in general practitioner practice. In: Chandra RK. Health Effects of Fish and F
Myasthenia gravis Other

Fish oil can contribute to caloric intake and may cause weight gain if used long-term. One gram of fat or oil provides 9 kcal. Fish oil capsules containing 500 mg omega-3 fatty acids in 1 gram of oil would supply about 13.5 kcal per capsule. Fish oil supplements also contain cholesterol in amounts from 1-6 mg per gram of fish oil.

  1. Mahan LK, Escott-Stump S. Krause's Food, Nutrition, and Diet Therapy. 9th edition. W.B. Saunders Co., Philadelphia, PA, 1996.
  2. Yetiv JZ. Clinical applications of fish oils. JAMA 1988;260:665-70.
  3. Kastrup EK. Drug Facts and Comparisons. 1998 ed. St. Louis, MO: Facts and Comparisons, 1998.
Skin irritation Dermatologic

Orally, skin rashes, itching, and skin irritation have been reported.

A case of severe tissue inflammation and breast tissue necrosis has been reported for a female who injected fish oil from capsules subcutaneously for breast augmentation.

  1. Kuenzel U and Bertsch S. Clinical experiences with a standardized commercial fish oil product containing 33.5% omega-3 fatty acids - field trial with 3958 hyperlipemic patients in general practitioner practice. In: Chandra RK. Health Effects of Fish and F
  2. Sydenham E, Dangour AD Lim WS. Omega 3 fatty acid for the prevention of cognitive decline and dementia. Cochrane Database Syst Rev. 2012;6:CD005379.
  3. Schachter, HM, Reisman, J, Tran, K, Dales, B, Kourad, K, Barnes, D, Sampson, M, Morrison, A, Gaboury, I, and Blackman, J. Health effects of omega-3 fatty acids on asthma. Evid.Rep.Technol.Assess.(Summ.) 2004;(91):1-7.
  4. Souied EH, Delcourt C, Querques G, Bassols A, Merle B, Zourdani A, Smith T, Benlian P; Nutritional AMD Treatment 2 Study Group. Oral docosahexaenoic acid in the prevention of exudative age-related macular degeneration: the Nutritional AMD Treatment 2 stud
  5. Suradom C, Suttajit S, Oon-Arom A, Maneeton B, Srisurapanont M. Omega-3 polyunsaturated fatty acid (n-3 PUFA) supplementation for prevention and treatment of perinatal depression: a systematic review and meta-analysis of randomized-controlled trials. Nord
  6. Turk E, Karagulle E, Koksal H, Togan T, Erinanc OH, Dogru O, Moray G. Bilateral breast necrosis due to local injection of fish oil. Breast J 2013;19(2):196-8.
DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.

Adverse-effects data: Natural Medicines, Therapeutic Research Center

Dosing

There is no single standard dose of fish oil for everyone, and the right amount depends on why it is being used and the EPA/DHA content of the product. The amount of actual omega-3s (EPA plus DHA) matters more than the total fish oil amount on the label.

Follow the directions on the product label and check with your pharmacist or doctor to find a dose that is right for you. Higher, prescription-strength doses used for very high triglycerides should only be used under a doctor's supervision.

Pregnancy & Breastfeeding

Fish Oil & Pregnancy

Likely Safe

When used orally and appropriately. Intake of fish oil during pregnancy does not appear to adversely affect the fetus or nursing infant. One large clinical trial shows that intake of fish oil from the 24th week of gestation increases the odds of the child having overweight and having metabolic syndrome measurements at age 10 when compared with placebo. More research is needed to confirm these findings. The adequate intake level of omega-3 fatty acids during pregnancy is 1.4 grams daily; the adequate intake level during lactation is 1.3 grams daily. If possible, people who are trying to become pregnant, as well as those who are pregnant or lactating, should avoid swordfish, king mackerel, and tilefish (also called golden bass or golden snapper), as these may contain high levels of methylmercury. Pregnant individuals should also limit consumption of other fatty fish to 12 ounces, or about 3-4 servings, per week.

  1. Onwude JL, Lilford RJ, Hjartardottir H, et al. A randomised double blind placebo controlled trial of fish oil in high risk pregnancy. Br J Obstet Gynaecol 1995;102:95-100.
  2. Bulstra-Ramakers MT, Huisjes HJ, Visser GH. The effects of 3g eicosapentaenoic acid daily on recurrence of intrauterine growth retardation and pregnancy induced hypertension. Br J Obstet Gynaecol 1995;102:123-6.
  3. D'Almeida A, Carter JP, Anatol A, Prost C. Effects of a combination of evening primrose oil (gamma linolenic acid) and fish oil (eicosapentaenoic + docahexaenoic acid) versus magnesium, and versus placebo in preventing pre-eclampsia. Women Health 1992;19
  4. Olsen SF, Sorensen JD, Secher NJ, et al. Randomised controlled trial of effect of fish-oil supplementation on pregnancy duration. Lancet 1992;339:1003-7.
  5. Dunstan JA, Roper J, Mitoulas L, et al. The effect of supplementation with fish oil during pregnancy on breast milk immunoglobulin A, soluble CD14, cytokine levels and fatty acid composition. Clin Exp Allergy 2004;34:1237-42.
  6. Lauritzen L, Jorgensen MH, Mikkelsen TB, et al. Maternal fish oil supplementation in lactation: effect on visual acuity and n-3 fatty acid content of infant erythrocytes. Lipids 2004;39:195-206.
  7. Dunstan JA, Mori TA, Barden A et al. Fish oil supplementation in pregnancy modifies neonatal allergen-specific immune responses and clinical outcomes in infants at high risk of atopy: a randomized, controlled trial. J Allergy Clin Immunol 2003;112:1178-84
  8. Olsen SF, Secher NJ, Tabor A, et al. Randomised clinical trials of fish oil supplementation in high risk pregnancies. Fish Oil Trials In Pregnancy (FOTIP) Team. BJOG 2000;107:382-95.
  9. Stern AH. A review of the studies of the cardiovascular health effects of methylmercury with consideration of their suitability for risk assessment. Environ Res 2005;98:133-42.
  10. Lauritzen L, Hoppe C, Straarup EM, Michaelsen KF. Maternal fish oil supplementation in lactation and growth during the first 2.5 years of life. Pediatr Res 2005;58:235-42.
  11. Dunstan JA, Mori TA, Barden A, et al. Effects of n-3 polyunsaturated fatty acid supplementation in pregnancy on maternal and fetal erythrocyte fatty acid composition. Eur J Clin Nutr 2004;58:429-37.
  12. Dunstan JA, Simmer K, Dixon G, Prescott SL. Cognitive assessment at 2 1/2 years following fish oil supplementation in pregnancy: a randomized controlled trial. Arch Dis Child Fetal Neonatal Ed 2008;93(1):F45-50.
  13. Vinding RK, Stokholm J, Sevelsted A, et al. Fish oil supplementation in pregnancy increases gestational age, size for gestational age, and birth weight in infants: A randomized controlled trial. J Nutr. 2019;149(4):628-634.
  14. Satokar VV, Derraik JGB, Harwood M, et al. Fish oil supplementation during pregnancy and postpartum in mothers with overweight and obesity to improve body composition and metabolic health during infancy: A double-blind randomized controlled trial. Am J Cl
  15. Sarrafi S, Pourzeinali S, Shakouri SK, Farshbaf-Khalili A, Ostadrahimi A. The effectiveness of perinatal omega-3 supplements in neurodevelopment and physical growth of 9- and 12-month-old infants: A follow-up of a clinical trial. Curr Pediatr Rev 2024.
  16. Vinding RK, Sevelsted A, Horner D, et al. Fish oil supplementation during pregnancy, anthropometrics, and metabolic health at age ten: A randomized clinical trial. Am J Clin Nutr 2024;119(4):960-968.
  17. Briggs GG, Freeman RK, and Yaffe SJ. Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk 10th edition. Lippinscott Williamns & Wilkins. Vol 25. No. 4, December 2012.
Possibly Unsafe

When fish oil from dietary sources are consumed in large amounts. Fatty fish can contain significant amounts of toxins such as mercury, polychlorinated biphenyls (PCBs), dioxin, and dioxin-related compounds. If possible, people who are trying to become pregnant, as well as those who are pregnant or lactating, should avoid swordfish, king mackerel, and tilefish (also called golden bass or golden snapper), as these may contain high levels of methylmercury. Pregnant individuals should also limit consumption of other fatty fish to 12 ounces, or about 3-4 servings, per week.

  1. US Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Seafood. Mercury levels in seafood species. Available at: http://www.cfsan.fda.gov/~frf/sea-mehg.html.
  2. US Environmental Protection Agency. Fish Advisories web page. Available at: http://www.epa.gov/waterscience/fish.

Fish Oil & Breastfeeding

Likely Safe

When used orally and appropriately. Intake of fish oil during pregnancy does not appear to adversely affect the fetus or nursing infant. One large clinical trial shows that intake of fish oil from the 24th week of gestation increases the odds of the child having overweight and having metabolic syndrome measurements at age 10 when compared with placebo. More research is needed to confirm these findings. The adequate intake level of omega-3 fatty acids during pregnancy is 1.4 grams daily; the adequate intake level during lactation is 1.3 grams daily. If possible, people who are trying to become pregnant, as well as those who are pregnant or lactating, should avoid swordfish, king mackerel, and tilefish (also called golden bass or golden snapper), as these may contain high levels of methylmercury. Pregnant individuals should also limit consumption of other fatty fish to 12 ounces, or about 3-4 servings, per week.

  1. Onwude JL, Lilford RJ, Hjartardottir H, et al. A randomised double blind placebo controlled trial of fish oil in high risk pregnancy. Br J Obstet Gynaecol 1995;102:95-100.
  2. Bulstra-Ramakers MT, Huisjes HJ, Visser GH. The effects of 3g eicosapentaenoic acid daily on recurrence of intrauterine growth retardation and pregnancy induced hypertension. Br J Obstet Gynaecol 1995;102:123-6.
  3. D'Almeida A, Carter JP, Anatol A, Prost C. Effects of a combination of evening primrose oil (gamma linolenic acid) and fish oil (eicosapentaenoic + docahexaenoic acid) versus magnesium, and versus placebo in preventing pre-eclampsia. Women Health 1992;19
  4. Olsen SF, Sorensen JD, Secher NJ, et al. Randomised controlled trial of effect of fish-oil supplementation on pregnancy duration. Lancet 1992;339:1003-7.
  5. Dunstan JA, Roper J, Mitoulas L, et al. The effect of supplementation with fish oil during pregnancy on breast milk immunoglobulin A, soluble CD14, cytokine levels and fatty acid composition. Clin Exp Allergy 2004;34:1237-42.
  6. Lauritzen L, Jorgensen MH, Mikkelsen TB, et al. Maternal fish oil supplementation in lactation: effect on visual acuity and n-3 fatty acid content of infant erythrocytes. Lipids 2004;39:195-206.
  7. Dunstan JA, Mori TA, Barden A et al. Fish oil supplementation in pregnancy modifies neonatal allergen-specific immune responses and clinical outcomes in infants at high risk of atopy: a randomized, controlled trial. J Allergy Clin Immunol 2003;112:1178-84
  8. Olsen SF, Secher NJ, Tabor A, et al. Randomised clinical trials of fish oil supplementation in high risk pregnancies. Fish Oil Trials In Pregnancy (FOTIP) Team. BJOG 2000;107:382-95.
  9. Stern AH. A review of the studies of the cardiovascular health effects of methylmercury with consideration of their suitability for risk assessment. Environ Res 2005;98:133-42.
  10. Lauritzen L, Hoppe C, Straarup EM, Michaelsen KF. Maternal fish oil supplementation in lactation and growth during the first 2.5 years of life. Pediatr Res 2005;58:235-42.
  11. Dunstan JA, Mori TA, Barden A, et al. Effects of n-3 polyunsaturated fatty acid supplementation in pregnancy on maternal and fetal erythrocyte fatty acid composition. Eur J Clin Nutr 2004;58:429-37.
  12. Dunstan JA, Simmer K, Dixon G, Prescott SL. Cognitive assessment at 2 1/2 years following fish oil supplementation in pregnancy: a randomized controlled trial. Arch Dis Child Fetal Neonatal Ed 2008;93(1):F45-50.
  13. Vinding RK, Stokholm J, Sevelsted A, et al. Fish oil supplementation in pregnancy increases gestational age, size for gestational age, and birth weight in infants: A randomized controlled trial. J Nutr. 2019;149(4):628-634.
  14. Satokar VV, Derraik JGB, Harwood M, et al. Fish oil supplementation during pregnancy and postpartum in mothers with overweight and obesity to improve body composition and metabolic health during infancy: A double-blind randomized controlled trial. Am J Cl
  15. Sarrafi S, Pourzeinali S, Shakouri SK, Farshbaf-Khalili A, Ostadrahimi A. The effectiveness of perinatal omega-3 supplements in neurodevelopment and physical growth of 9- and 12-month-old infants: A follow-up of a clinical trial. Curr Pediatr Rev 2024.
  16. Vinding RK, Sevelsted A, Horner D, et al. Fish oil supplementation during pregnancy, anthropometrics, and metabolic health at age ten: A randomized clinical trial. Am J Clin Nutr 2024;119(4):960-968.
  17. Briggs GG, Freeman RK, and Yaffe SJ. Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk 10th edition. Lippinscott Williamns & Wilkins. Vol 25. No. 4, December 2012.
Possibly Unsafe

When fish oil from dietary sources are consumed in large amounts. Fatty fish can contain significant amounts of toxins such as mercury, polychlorinated biphenyls (PCBs), dioxin, and dioxin-related compounds. If possible, people who are trying to become pregnant, as well as those who are pregnant or lactating, should avoid swordfish, king mackerel, and tilefish (also called golden bass or golden snapper), as these may contain high levels of methylmercury. Pregnant individuals should also limit consumption of other fatty fish to 12 ounces, or about 3-4 servings, per week.

  1. US Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Seafood. Mercury levels in seafood species. Available at: http://www.cfsan.fda.gov/~frf/sea-mehg.html.
  2. US Environmental Protection Agency. Fish Advisories web page. Available at: http://www.epa.gov/waterscience/fish.
DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.

© 2026 Therapeutic Research Center

Pregnancy & lactation ratings: Natural Medicines, Therapeutic Research Center

References & further reading

The 157 references that drive our Fish Oil monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Prisco D, Paniccia R, Bandinelli B, et al. Effect of medium-term supplementation with a moderate dose of n-3 polyunsaturated fatty acids on blood pressure in mild hypertensive patients. Thromb Res 1998;1:105-12.
  2. Allard JP, Kurian R, Aghdassi E, Muggli R, et al. Lipid peroxidation during n-3 fatty acid and vitamin E supplementation in humans. Lipids 1997;32:535-41.. PubMed
  3. Toft I, Bonaa KH, Ingebretsen OC, et al. Effects of n-3 polyunsaturated fatty acids on glucose homeostasis and blood pressure in essential hypertension. A randomized, controlled trial. Ann Intern Med 1995;123:911-8.
  4. Onwude JL, Lilford RJ, Hjartardottir H, et al. A randomised double blind placebo controlled trial of fish oil in high risk pregnancy. Br J Obstet Gynaecol 1995;102:95-100. PubMed
  5. Bulstra-Ramakers MT, Huisjes HJ, Visser GH. The effects of 3g eicosapentaenoic acid daily on recurrence of intrauterine growth retardation and pregnancy induced hypertension. Br J Obstet Gynaecol 1995;102:123-6. PubMed
  6. Sacks FM, Hebert P, Appel LJ, et al. Short report: the effect of fish oil on blood pressure and high-density lipoprotein-cholesterol levels in phase I of the trials of hypertension prevention. J Hypertens 1994;12:209-13.
  7. Vandongen R, Mori TA, Burke V, et al. Effects on blood pressure of omega 3 fats in subjects at increased risk of cardiovascular disease. Hypertension 1993;22:371-9. PubMed
  8. Hawthorne AB, Daneshmend TK, Hawkey CJ, et al. Treatment of ulcerative colitis with fish oil supplementation: a prospective 12 month randomised controlled trial. Gut 1992;33:922-8. PubMed
  9. D'Almeida A, Carter JP, Anatol A, Prost C. Effects of a combination of evening primrose oil (gamma linolenic acid) and fish oil (eicosapentaenoic + docahexaenoic acid) versus magnesium, and versus placebo in preventing pre-eclampsia. Women Health 1992;19 PubMed
  10. FDA. Center for Food Safety and Applied Nutrition. Letter regarding dietary supplement health claim for omega-3 fatty acids and coronary heart disease. Available at: http://www.fda.gov/ohrms/dockets/dockets/95s0316/95s-0316-Rpt0272-38-Appendix-D-Reference
  11. Montori VM, Farmer A, Wollan PC, Dinneen SF. Fish oil supplementation in type 2 diabetes: a quantitative systemic review (abstract). Diabetes Care 2000;23:1407-15.
  12. Anon. Dietary supplementation with n-3 polyunsaturated fatty acids and vitamin E after myocardial infarction: results of the GISSI-Prevenzione trial. Gruppo Italiano per lo Studio della Soprawivenza nell'Infarto miocardico. Lancet 1999;354:447-55. DOI
  13. Adler A, Holub BJ. Effect of garlic and fish-oil supplementation on serum lipid and lipoprotein concentrations in hypercholesterolemic men. Am J Clin Nutr 1997;65:445-50. PubMed
  14. Higdon JV, Liu J, Du S, et al. Supplementation of postmenopausal women with fish oil rich in eicosapentaenoic acid and docosahexaenoic acid is not associated with greater in vivo lipid peroxidation compared with oils rich in oleate and linoleate as asses
  15. Kastrup EK. Drug Facts and Comparisons. 1998 ed. St. Louis, MO: Facts and Comparisons, 1998.
Keep reading

This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Brand directory

Brands that make products with Fish Oil

775 brands in our database make a supplement containing Fish Oil.

Product directory

Supplement products with Fish Oil

6,053 products in our database contain Fish Oil. Open any to see its full ingredient list and every drug interaction we check.

+Omega OmegaGuard by Shaklee Softgel Capsule 180 Softgel(s) View ingredients & interactions 1-TDC by Elite Science Softgel Capsule 90 Softgel(s) View ingredients & interactions 100% Platinum Fish Oil by MuscleTech Essential Series Softgel Capsule 100 softgel cap(s) View ingredients & interactions 13 Powerful Food Digestion Enzymes by Nature's Secret Softgel Capsule 60 Liquid Softgel(s) View ingredients & interactions 1300 mg Omega 3-6-9 Fish, Flax, Borage by Solgar Softgel Capsule 120 Softgel(s) View ingredients & interactions 180/120 Fish Oil 1000 mg by Esmond Natural Softgel Capsule 100 Softgel(s) View ingredients & interactions 2-in-1 Kidney & Liver Super Cleanse by Irwin Naturals Softgel Capsule 60 Liquid Soft-Gel(s) View ingredients & interactions 3-in-1 Complete Probiotic by Culturelle Capsule 30 Once daily capsule(s) View ingredients & interactions 3-in-1 Joint Formula by Irwin Naturals Softgel Capsule 90 Liquid Softgel(s) View ingredients & interactions 4Life Transfer Factor Plus RiteStart Men by 4Life Unknown 30 Packet(s) View ingredients & interactions 70% DHA Fish Oil Softgels 1,000 mg by Nootropics Depot Softgel Capsule 180 Softgel(s) View ingredients & interactions 70% DHA Fish Oil Softgels 1000 mg by Nootropics Depot Softgel Capsule 60 Softgel(s) View ingredients & interactions A+ Fish Oil Tutti Frutti Flavor by Health From The Sun Liquid 4 fl. Oz. · 118 mL View ingredients & interactions Ab Cuts by Corr-Jensen Softgel Capsule 120 Softgel(s) View ingredients & interactions Able Eyes by Carlson Softgel Capsule 90 Softgel(s) View ingredients & interactions Able Eyes by Carlson Softgel Capsule 60 Softgel(s) View ingredients & interactions Able Eyes by Carlson Softgel Capsule 180 Softgel(s) View ingredients & interactions Able Eyes by Carlson Softgel Capsule 30 Softgel(s) View ingredients & interactions Accelon Omega-3 Fish Oil Softgels by Nootropics Depot Softgel Capsule 90 Softgel(s) View ingredients & interactions ACES + Omega by Carlson Softgel Capsule 60 Softgel(s) View ingredients & interactions ACES + Omega by Carlson Softgel Capsule 180 Softgel(s) View ingredients & interactions ACES + Omega by Carlson Softgel Capsule 120 Softgel(s) View ingredients & interactions Active Multi Packs by MET-Rx Unknown 30 Day Supply Packet(s) View ingredients & interactions Active-Male Brain Awake MAX3 + Nitric Oxide Booster by Irwin Naturals Softgel Capsule 60 Liquid Soft-Gel(s) View ingredients & interactions
Pharmacist Counseling Corner

Fish Oil: Common Questions

What is Fish Oil used for, and does it work?
People use Fish Oil for many reasons, but the evidence varies by use. According to the Natural Medicines database, there is at least some clinical evidence supporting Fish Oil for Hypertriglyceridemia, Angioplasty, Cachexia and Cyclosporine-induced nephrotoxicity. For most other uses it has been studied for, the evidence is currently insufficient to rate. See the graded list on this page, and always confirm with your pharmacist or doctor.
Does Fish Oil interact with prescription medications?
Yes. We list 327 medications with a known interaction with Fish Oil. Use the checker above to see how Fish Oil interacts with a specific drug.
How are Fish Oil interactions rated?
Each interaction is graded major, moderate, or minor based on how clinically significant it is and the strength of the evidence behind it. Major interactions are the most serious and are best avoided, or used only under close professional supervision.
Is it safe to take Fish Oil with my medications?
It depends on the specific medication. Some combinations are fine, while others call for monitoring, timing changes, or should be avoided. Check your exact drug above and confirm with your pharmacist or doctor before starting, stopping, or changing anything.
Where does this Fish Oil interaction information come from?
Our interaction data is built on the Natural Medicines database — an evidence-graded reference for vitamins, herbs, and supplements — and is reviewed by licensed HelloPharmacist pharmacists, who may add clinical context.
What is Fish Oil used for?
Fish Oil is most commonly used to lower high triglyceride levels and support general heart health. People also take it for joint pain, dry eyes, and brain health, though the evidence for these uses is mixed or limited.
Is Fish Oil safe to take every day?
For most healthy adults, daily Fish Oil at typical supplement doses is generally well tolerated. If you have a fish allergy, a bleeding disorder, or take blood thinners, check with your pharmacist or doctor first.
Can I take Fish Oil during pregnancy or breastfeeding?
Omega-3s like DHA are important during pregnancy and breastfeeding, but supplement use should be guided by your doctor, and you should avoid fish high in mercury.
How can I avoid fishy burps?
Taking Fish Oil with meals, splitting the dose, keeping capsules in the freezer, or using enteric-coated products can help reduce fishy aftertaste and burping.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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