Evening Primrose Oil 500 mg Ingredients & Drug Interactions
by Solgar
What is this page for?
First and foremost: checking Evening Primrose Oil 500 mg against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.
Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy
Evening Primrose Oil 500 mg is a dietary supplement by Solgar with 6 active ingredients. Its ingredients are commonly taken for heart health, healthy cooking fat, skin moisturizing.Based on those ingredients, 308 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Evening Primrose Oil, Oleic Acid. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.
Check Your Meds Against Evening Primrose Oil 500 mg by Solgar
Ask about any prescription or over-the-counter medication and we check it for interactions with Evening Primrose Oil 500 mg by Solgar — and tell you which ingredient is responsible.
AI summaries are generated from our interaction database for education only — always confirm with your pharmacist. How we use AI
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HelloPharmacist Scorecard of Evening Primrose Oil 500 mg by Solgar
Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.
What’s inside
Full disclosure
This softgel contains 500 mg of evening primrose oil — a plant oil rich in fatty acids including gamma-linolenic acid, linoleic acid, oleic acid, and palmitic acid. Evening primrose oil is the active ingredient; the softgel shell is made from gelatin and vegetable glycerin.
Does it work?
Not established
Evening primrose oil's track record in clinical trials is mixed. The evidence rates it as likely ineffective for breast pain (mastalgia) and possibly ineffective for asthma.
For attention deficit-hyperactivity disorder (ADHD), acne, and several other uses, we don't have enough reliable evidence to know whether it works. Oleic acid — one of the fatty acids in the product — is rated possibly effective for high cholesterol and coronary heart disease, but the amount in evening primrose oil hasn't been clearly studied for these outcomes.
How safe is it?
Well-documented data
Evening primrose oil is generally well tolerated in the short term, though quality evidence on long-term safety is limited. Common side effects from oral use include stomach pain, bloating, diarrhea, indigestion, gas, nausea, and vomiting.
A small number of users have reported headache, dizziness, skin rash, or acne. The safety data advises against use during pregnancy unless your doctor directs you otherwise.
For breastfeeding, the data rates it as possibly safe, but discuss it with your doctor or pharmacist given the limited information available.
Meds to double-check
Moderate interaction found
Before taking this product, double-check with your doctor or pharmacist if you're on blood thinners (anticoagulants or antiplatelet drugs), lithium, phenothiazines (antipsychotics), or lopinavir/ritonavir (Kaletra). Also mention any medications your liver processes through the CYP2C9 enzyme — evening primrose oil may raise their levels.
These are Moderate to Minor severity interactions and warrant a conversation with your healthcare provider.
The bottom line
Scorecard at a glanceFully disclosed formula with no established evidence rating for its marketed use. Moderate medication interactions have been identified, and safety information is well characterized.
If you take blood thinners, lithium, antipsychotic medications, or HIV protease inhibitors, check with your doctor or pharmacist before starting this product — the interactions are real and could affect how your medicines work. For everyone else without those medications, the main consideration is that it's not well studied long-term and hasn't proven effective for most conditions people try it for.
A conversation with your own pharmacist about whether it fits your needs is worth having.
Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI
Assessment coverage: 2 of 6 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Feb 26, 2020.
This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed
General information
Key facts about Evening Primrose Oil 500 mg, straight from the product label.
| Brand | Solgar |
|---|---|
| Barcode (UPC) | 033984010406 |
| Net contents | 30 Softgel(s) |
| Market status | On market |
| Date entered into DSLD | Feb 26, 2020 |
| DSLD ID | 214020 |
| Product type | Fat/fatty Acid |
| Supplement form | Softgel Capsule |
| Dietary claims / uses | Nutrient, All Other, Structure/Function |
| Intended target group(s) | Adult Female (18 - 50 Years), Gluten Free, Dairy Free, Sugar Free |
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.
Supplement Facts
The label details for Evening Primrose Oil 500 mg by Solgar, sourced from the NIH Dietary Supplement Label Database.
Supplement Facts
| Ingredient | Amount | % DV |
|---|---|---|
| Calories | 5 Calorie(s) | -- |
| Gamma-Linolenic Acid | 50 mg | -- |
| Linoleic Acid | 365 mg | -- |
| Oleic Acid | 20 mg | -- |
| Palmitic Acid | 30 mg | -- |
| Other Fatty Acids | 35 mg | -- |
| Evening Primrose Oil | 500 mg | -- |
Other ingredients: Gelatin, Vegetable Glycerin
Tap any ingredient to jump to its full detail below.
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Formula
Evening Primrose Oil is one of the richest sources of the unsaturated fatty acid Gamma Linolenic Acid (GLA), which is essential for women's nutrition.
Source of GLA
Formulation
This formulation provides premium quality primrose oil, cold pressed without the use of chemical solvents.
Cold pressed
Gluten, wheat & dairy free
Free of: Gluten, wheat, dairy, soy, yeast, sugar, sodium, artificial flavor, sweetener, preservatives and color.
FDA Disclaimer Statement
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.
General Statements
For more information, call toll-free 1-877-SOLGAR 4 www.solgar.com
Solgar since 1947
Brand IP Statement(s)
2009 Solgar, Inc.
FDA Statement of Identity
Dietary Supplement
Suggested/Recommended/Usage/Directions
Suggested Use: As a dietary supplement for adults, take one (1) to three (3) softgels daily, preferably at mealtimes, or as directed by a healthcare practitioner.
Precautions
If you are pregnant, nursing, taking any medication or have a medical condition, please consult your healthcare practitioner before taking any dietary supplement.
Keep out of reach of children.
Do not use if outer bottle seal is missing, torn or damaged in any way.
Storage
Store in a cool, dry place.
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
Evening Primrose Oil 500 mg by Solgar label
The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.
Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.
View the full label (PDF)The Ingredients in Evening Primrose Oil 500 mg by Solgar
These are the 6 active ingredients this product is made of. Select any to open its full monograph.
Serving size1 Softgel(s) Dosage formSoftgel Capsule Amounts shown are per serving.
Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.
Gamma-Linolenic Acid
Linoleic Acid
Oleic Acid
Interacts with86 drugs
Oleic acid is a heart-healthy monounsaturated fat found mainly in olive oil, canola oil, avocados, and nuts. As part of a Mediterranean-style diet, it...
Oleic Acid monograph & interactionsPalmitic Acid
Other Fatty Acids
Evening Primrose Oil
Interacts with233 drugs
Evening primrose oil is a seed oil rich in gamma-linolenic acid (GLA), an omega-6 fatty acid, that is popularly used for skin conditions, PMS, and bre...
Evening Primrose Oil monograph & interactionsOther (inactive) ingredients: Gelatin, Vegetable Glycerin. These complete the product’s ingredient list but are not active constituents.
Evening Primrose Oil 500 mg by Solgar Drug Interactions
HelloPharmacist Interaction Report
Solgar's Evening Primrose Oil 500 mg contains two ingredients with documented drug interactions: oleic acid and evening primrose oil itself.
The most serious concern is a Moderate-severity interaction with blood thinners (anticoagulant/antiplatelet drugs) — evening primrose oil may increase bleeding risk by reducing how quickly blood clots form.
Read the full breakdown — every affected drug type, severity by severity
Evening primrose oil also interacts moderately with lithium (a mood stabilizer), where it may lower lithium levels and reduce its effectiveness. There's a similar Moderate concern with phenothiazines (antipsychotic medications), which theoretically could increase seizure risk.
The HIV protease inhibitor lopinavir/ritonavir (Kaletra) may see increased levels in your blood if combined with this supplement. Additionally, evening primrose oil may increase the levels of drugs processed by a liver enzyme called CYP2C9 — a Minor interaction affecting a broader range of medications.
We could not check three other fatty acid ingredients in this product: gamma-linolenic acid, linoleic acid, and palmitic acid. Altogether, these interactions span 308 individual medications.
Use the medication checker on this page to see if any of your prescriptions are affected.
Check your own medications below · Editorial policy · How we use AI
Want to check YOUR meds against Evening Primrose Oil 500 mg?
Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.
Go to the checkerIngredients driving the most interactions
Individual Drug Interactions
The ingredients in Evening Primrose Oil 500 mg interact with 308 drugs. Click any drug to see the details.
2 of the 6 ingredients in Evening Primrose Oil 500 mg interact with drugs. Each result below shows which ingredient is responsible. Evening Primrose Oil Oleic Acid
AbciximabReoPro
How Abciximab interacts with Evening Primrose Oil 500 mg — through 1 ingredient. Tap an ingredient for the detail:
Evening Primrose OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Evening Primrose Oil + Abciximab interactionAbrocitinibCibinqo
How Abrocitinib interacts with Evening Primrose Oil 500 mg — through 1 ingredient. Tap an ingredient for the detail:
Evening Primrose OilCytochrome P450 2c9 (cyp2c9) Substrates, Anticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose may increase the levels and clinical effects of CYP2C9 substrates.
Read the full Evening Primrose Oil + Abrocitinib interactionAcarboseGlucobay, Prandase, Precose
How Acarbose interacts with Evening Primrose Oil 500 mg — through 1 ingredient. Tap an ingredient for the detail:
Oleic AcidAntidiabetes Drugs Moderate
Interaction Summary
Theoretically, oleic acid might increase the effects of antidiabetes drugs.
Read the full Oleic Acid + Acarbose interactionAcenocoumarolSintrom
How Acenocoumarol interacts with Evening Primrose Oil 500 mg — through 1 ingredient. Tap an ingredient for the detail:
Evening Primrose OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Evening Primrose Oil + Acenocoumarol interactionAcepromazineAtravet
How Acepromazine interacts with Evening Primrose Oil 500 mg — through 1 ingredient. Tap an ingredient for the detail:
Evening Primrose OilPhenothiazines Moderate
Interaction Summary
Theoretically, taking evening primrose oil with phenothiazines might increase the risk of convulsions.
Read the full Evening Primrose Oil + Acepromazine interactionAcetaminophen, AspirinGemnisyn
How Acetaminophen, Aspirin interacts with Evening Primrose Oil 500 mg — through 1 ingredient. Tap an ingredient for the detail:
Evening Primrose OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Evening Primrose Oil + Acetaminophen, Aspirin interactionAcetaminophen, Aspirin, CaffeineExcedrin, Excedrin Extra Strength, Excedrin Migraine
How Acetaminophen, Aspirin, Caffeine interacts with Evening Primrose Oil 500 mg — through 1 ingredient. Tap an ingredient for the detail:
Evening Primrose OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Evening Primrose Oil + Acetaminophen, Aspirin, Caffeine interactionAcetaminophen, IbuprofenCombogesic
How Acetaminophen, Ibuprofen interacts with Evening Primrose Oil 500 mg — through 1 ingredient. Tap an ingredient for the detail:
Evening Primrose OilCytochrome P450 2c9 (cyp2c9) Substrates, Anticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose may increase the levels and clinical effects of CYP2C9 substrates.
Read the full Evening Primrose Oil + Acetaminophen, Ibuprofen interactionAcetohexamideDymelor
How Acetohexamide interacts with Evening Primrose Oil 500 mg — through 1 ingredient. Tap an ingredient for the detail:
Oleic AcidAntidiabetes Drugs Moderate
Interaction Summary
Theoretically, oleic acid might increase the effects of antidiabetes drugs.
Read the full Oleic Acid + Acetohexamide interactionAcetylsalicylic AcidEntrophen
How Acetylsalicylic Acid interacts with Evening Primrose Oil 500 mg — through 1 ingredient. Tap an ingredient for the detail:
Evening Primrose OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Evening Primrose Oil + Acetylsalicylic Acid interactionAlbiglutideTanzeum
How Albiglutide interacts with Evening Primrose Oil 500 mg — through 1 ingredient. Tap an ingredient for the detail:
Oleic AcidAntidiabetes Drugs Moderate
Interaction Summary
Theoretically, oleic acid might increase the effects of antidiabetes drugs.
Read the full Oleic Acid + Albiglutide interactionAlogliptinNesina
How Alogliptin interacts with Evening Primrose Oil 500 mg — through 1 ingredient. Tap an ingredient for the detail:
Oleic AcidAntidiabetes Drugs Moderate
Interaction Summary
Theoretically, oleic acid might increase the effects of antidiabetes drugs.
Read the full Oleic Acid + Alogliptin interactionAlogliptin, MetforminKazano
How Alogliptin, Metformin interacts with Evening Primrose Oil 500 mg — through 1 ingredient. Tap an ingredient for the detail:
Oleic AcidAntidiabetes Drugs Moderate
Interaction Summary
Theoretically, oleic acid might increase the effects of antidiabetes drugs.
Read the full Oleic Acid + Alogliptin, Metformin interactionAlogliptin, PioglitazoneOseni
How Alogliptin, Pioglitazone interacts with Evening Primrose Oil 500 mg — through 1 ingredient. Tap an ingredient for the detail:
Oleic AcidAntidiabetes Drugs Moderate
Interaction Summary
Theoretically, oleic acid might increase the effects of antidiabetes drugs.
Read the full Oleic Acid + Alogliptin, Pioglitazone interactionAlteplase, TpaActilyse, Activase
How Alteplase, Tpa interacts with Evening Primrose Oil 500 mg — through 1 ingredient. Tap an ingredient for the detail:
Evening Primrose OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Evening Primrose Oil + Alteplase, Tpa interactionAluminum Hydroxide, Aspirin, Codeine Phosphate, Magnesium HydroxideAscriptin Codeine #2
How Aluminum Hydroxide, Aspirin, Codeine Phosphate, Magnesium Hydroxide interacts with Evening Primrose Oil 500 mg — through 1 ingredient. Tap an ingredient for the detail:
Evening Primrose OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Evening Primrose Oil + Aluminum Hydroxide, Aspirin, Codeine Phosphate, Magnesium Hydroxide interactionAluminum Hydroxide, Aspirin, Magnesium HydroxideAscriptin
How Aluminum Hydroxide, Aspirin, Magnesium Hydroxide interacts with Evening Primrose Oil 500 mg — through 1 ingredient. Tap an ingredient for the detail:
Evening Primrose OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Evening Primrose Oil + Aluminum Hydroxide, Aspirin, Magnesium Hydroxide interactionAmitriptyline, PerphenazineEtrafon, Etrafon-A, Etrafon-Forte, Triavil
How Amitriptyline, Perphenazine interacts with Evening Primrose Oil 500 mg — through 1 ingredient. Tap an ingredient for the detail:
Evening Primrose OilCytochrome P450 2c9 (cyp2c9) Substrates, Phenothiazines Moderate
Interaction Summary
Theoretically, evening primrose may increase the levels and clinical effects of CYP2C9 substrates.
Read the full Evening Primrose Oil + Amitriptyline, Perphenazine interactionAnacaulase-bcdbNexoBrid
How Anacaulase-bcdb interacts with Evening Primrose Oil 500 mg — through 1 ingredient. Tap an ingredient for the detail:
Evening Primrose OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Evening Primrose Oil + Anacaulase-bcdb interactionAnagrelideAgrylin
How Anagrelide interacts with Evening Primrose Oil 500 mg — through 1 ingredient. Tap an ingredient for the detail:
Evening Primrose OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Evening Primrose Oil + Anagrelide interactionAnisindioneMiradon
How Anisindione interacts with Evening Primrose Oil 500 mg — through 1 ingredient. Tap an ingredient for the detail:
Evening Primrose OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Evening Primrose Oil + Anisindione interactionAntidiabetes, Dipeptidyl Peptidase-4 (dpp-iv) InhibitorGlyxambi
How Antidiabetes, Dipeptidyl Peptidase-4 (dpp-iv) Inhibitor interacts with Evening Primrose Oil 500 mg — through 1 ingredient. Tap an ingredient for the detail:
Oleic AcidAntidiabetes Drugs Moderate
Interaction Summary
Theoretically, oleic acid might increase the effects of antidiabetes drugs.
Read the full Oleic Acid + Antidiabetes, Dipeptidyl Peptidase-4 (dpp-iv) Inhibitor interactionAntithrombin IiiThrombate III
How Antithrombin Iii interacts with Evening Primrose Oil 500 mg — through 1 ingredient. Tap an ingredient for the detail:
Evening Primrose OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Evening Primrose Oil + Antithrombin Iii interactionApixabanEliquis
How Apixaban interacts with Evening Primrose Oil 500 mg — through 1 ingredient. Tap an ingredient for the detail:
Evening Primrose OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Evening Primrose Oil + Apixaban interactionArgatrobanArgatroban
How Argatroban interacts with Evening Primrose Oil 500 mg — through 1 ingredient. Tap an ingredient for the detail:
Evening Primrose OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Evening Primrose Oil + Argatroban interactionAspirinAngettes 75, ASA, Asaphen, Aspirin, Caprin, Cartia +8 more
How Aspirin interacts with Evening Primrose Oil 500 mg — through 1 ingredient. Tap an ingredient for the detail:
Evening Primrose OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Evening Primrose Oil + Aspirin interactionAspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium HydroxideAscriptin Codeine #3
How Aspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium Hydroxide interacts with Evening Primrose Oil 500 mg — through 1 ingredient. Tap an ingredient for the detail:
Evening Primrose OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Evening Primrose Oil + Aspirin, Aluminum Hydroxide, Codeine Phosphate, Magnesium Hydroxide interactionAspirin, ButalbitalAxotal
How Aspirin, Butalbital interacts with Evening Primrose Oil 500 mg — through 1 ingredient. Tap an ingredient for the detail:
Evening Primrose OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Evening Primrose Oil + Aspirin, Butalbital interactionAspirin, Butalbital, CaffeineFiorinal
How Aspirin, Butalbital, Caffeine interacts with Evening Primrose Oil 500 mg — through 1 ingredient. Tap an ingredient for the detail:
Evening Primrose OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Evening Primrose Oil + Aspirin, Butalbital, Caffeine interactionAspirin, Butalbital, Caffeine, Codeine PhosphateFiorinal w/ Codeine
How Aspirin, Butalbital, Caffeine, Codeine Phosphate interacts with Evening Primrose Oil 500 mg — through 1 ingredient. Tap an ingredient for the detail:
Evening Primrose OilAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Read the full Evening Primrose Oil + Aspirin, Butalbital, Caffeine, Codeine Phosphate interactionEach ingredient & the kinds of drugs it affects
For each ingredient in Evening Primrose Oil 500 mg with known interactions, here are the types of medications they can affect. Open any type for the detail — or search your exact drug in the checker above.
Evening Primrose Oil
Anticoagulant/Antiplatelet Drugs
Theoretically, evening primrose oil may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Evening primrose oil contains gamma linolenic acid (GLA). There is preliminary clinical evidence that GLA can reduce platelet aggregation and prolong bleeding time.
Lithium
Theoretically, concomitant use of lithium with evening primrose oil might decrease lithium levels and effects.
In a case report, a patient on a stable dose of lithium for 10 years experienced a reduction in lithium levels after taking evening primrose oil 500 mg daily. Baseline levels were 0.69 mmol/L, which decreased to 0.37 mmol/L after 2 months and 0.23 mmol/L after 3 months of use. Lithium levels increased within 6 weeks of discontinuing evening primrose oil, to 0.73 mmol/L; no clinical effects were noted.
Lopinavir/Ritonavir (Kaletra)
Theoretically, evening primrose oil might increase the levels and effects of lopinavir.
In a case report, an HIV patient who took evening primrose oil (Efamol) along with lopinavir/ritonavir experienced an increase in serum levels of lopinavir to 15.2 mg/L. Six weeks after discontinuing evening primrose oil, levels of lopinavir returned to the normal range of 5-10 mg/L. When re-challenged with evening primrose oil for a week, the patient's lopinavir levels increased from 6.69 to 8.11 mg/L. It is suspected that evening primrose oil increases levels of lopinavir by inhibiting cytochrome P450 3A4 (CYP3A4), which metabolizes lopinavir. However, this effect has not been reported in other research.
Phenothiazines
Theoretically, taking evening primrose oil with phenothiazines might increase the risk of convulsions.
Evening primrose oil contains gamma-linolenic acid (GLA). There is some concern that taking supplements containing GLA might cause seizures, or lower the seizure threshold, when taken with phenothiazines. In one report, three patients with schizophrenia who had received phenothiazines developed EEG changes suggestive of temporal lobe epilepsy after starting treatment with GLA, although none experienced an actual seizure. In another report, two patients with schizophrenia who were stabilized on phenothiazines developed seizures when evening primrose oil 4 grams daily was added. One of these patients had a prior history of seizures. It is unclear whether evening primrose oil had any additive epileptogenic effects with the phenothiazines; there is no evidence that taking evening primrose oil alone causes seizures.
Cytochrome P450 2C9 (Cyp2C9) Substrates
Theoretically, evening primrose may increase the levels and clinical effects of CYP2C9 substrates.
In vitro research shows that linoleic acid, a constituent of evening primrose oil, inhibits CYP2C9.
Oleic Acid
Antidiabetes Drugs
Theoretically, oleic acid might increase the effects of antidiabetes drugs. Preliminary clinical research in patients with type 2 diabetes taking oral hypoglycemic drugs shows that eating a diet rich in oleic acid from olive oil decreases fasting blood glucose levels when compared to eating a diet rich in linoleic acid from sunflower oil. It is unknown if taking oleic acid supplements would have this effect or if this change is clinically significant. Until more is known, use caution. Dose adjustment may be necessary. Some antidiabetes drugs include glimepiride (Amaryl), glyburide (DiaBeta, Glynase PresTab, Micronase), insulin, metformin (Glucophage), pioglitazone (Actos), rosiglitazone (Avandia), and others.
Brand information
Manufacturer and brand details for Evening Primrose Oil 500 mg, from the product label.
Solgar
See all Solgar products- Name
- Solgar, Inc.
- Street Address
- 500 Willow Tree Road
- City
- Leonia
- State
- NJ
- ZipCode
- 07605
- Phone Number
- 1-877-765-4274
- Web Address
- www.solgar.com
Evening Primrose Oil 500 mg by Solgar: Common Questions
Does Evening Primrose Oil 500 mg by Solgar interact with any medications?
How can one product interact with so many drugs?
Where does this information come from?
Can I take this if I'm pregnant?
What side effects should I watch for?
Does evening primrose oil actually work for anything?
Is this safe to use long-term?
Why does the interaction list have so many medications?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Not sure if Evening Primrose Oil 500 mg is safe with your meds?
Our pharmacists answer your medication & supplement questions — free.
Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.
The Full Monographs Behind Evening Primrose Oil 500 mg’s Ingredients
Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.
Oleic Acid
Interacts with 86 drugsOleic acid is a heart-healthy monounsaturated fat found mainly in olive oil, canola oil, avocados, and nuts. As part of a Mediterranean-style diet, it is widely viewed as a healthier replace...
Read the full Oleic Acid monograph → Herb & supplement monographEvening Primrose
Interacts with 233 drugsEvening primrose oil is a seed oil rich in gamma-linolenic acid (GLA), an omega-6 fatty acid, that is popularly used for skin conditions, PMS, and breast pain. The evidence behind most of th...
Read the full Evening Primrose monograph →Sources & How We Checked
Evening Primrose Oil 500 mg's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.
- NIH Dietary Supplement Label Database (DSLD) — The official product label on file for this supplement.
- Natural Medicines (Therapeutic Research Center) — Evidence-graded clinical reference behind the ingredient interaction data.
Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.
The 52 references behind this product’s interaction data
Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.
Oleic Acid 19 references
- Madigan C, Ryan M, Owens D, et al. Dietary unsaturated fatty acids in type 2 diabetes: higher levels of postprandial lipoprotein on a linoleic acid-rich sunflower oil diet compared with an oleic acid-rich olive oil diet. Diabetes Care 2000;23:1472-7. PubMed
- Gillingham, L. G., Gustafson, J. A., Han, S. Y., Jassal, D. S., and Jones, P. J. High-oleic rapeseed (canola) and flaxseed oils modulate serum lipids and inflammatory biomarkers in hypercholesterolaemic subjects. Br J Nutr 2011;105(3):417-427. PubMed
- Jones PJ, Senanayake VK, Pu S, Jenkins DJ, Connelly PW, Lamarche B, Couture P, Charest A, Baril-Gravel L, West SG, Liu X, Fleming JA, McCrea CE, Kris-Etherton PM. DHA-enriched high-oleic acid canola oil improves lipid profile and lowers predicted cardiova
- Cater, N. B., Heller, H. J., and Denke, M. A. Comparison of the effects of medium-chain triacylglycerols, palm oil, and high oleic acid sunflower oil on plasma triacylglycerol fatty acids and lipid and lipoprotein concentrations in humans. Am.J Clin.Nutr PubMed
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