Evening Primrose Ingredients & Drug Interactions
by Nature's Way
What is this page for?
First and foremost: checking Evening Primrose 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 is a dietary supplement by Nature's Way with 2 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 by Nature's Way
Ask about any prescription or over-the-counter medication and we check it for interactions with Evening Primrose by Nature's Way — 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 by Nature's Way
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
Partial disclosure
Evening Primrose by Nature's Way is a softgel capsule with 6 active ingredients, all fatty acids and related compounds from evening primrose oil. The product contains gamma-linolenic acid, omega-6 fatty acids, monounsaturated fat, linoleic acid, oleic acid, and polyunsaturated fat — a blend of the natural fats that make up the oil itself.
The capsules also contain gelatin, glycerin, and purified water as inactive ingredients (the capsule shell and preservatives).
Does it work?
Moderate evidence
The omega-6 fatty acids in this product are rated possibly ineffective for hyperlipidemia (high cholesterol), cardiovascular disease, child development, and multiple sclerosis based on the evidence we hold. Oleic acid, another ingredient here, is rated possibly effective for high cholesterol and coronary heart disease.
Overall, the supplement evidence for evening primrose oil in these areas is mixed and modest.
How safe is it?
Well-documented data
Omega-6 fatty acids from food are generally well tolerated, but the safety of concentrated supplements like evening primrose oil is not well established. The research notes that very high omega-6 intake, especially when omega-3 intake is low, may carry risks — higher ratios of omega-6 to omega-3 are thought to increase cardiovascular risk, and some studies link high omega-6 levels to cancer risk and mood symptoms, though the role remains unclear.
For pregnancy and breastfeeding, omega-6 fatty acids from this product are rated possibly unsafe, so talk with your doctor before taking it if you're pregnant or nursing. Oleic acid safety in pregnancy is not well studied at supplement doses, though food amounts are considered safe.
Meds to double-check
Moderate interaction found
If you take antidiabetes drugs (blood sugar medications), talk with your doctor or pharmacist before adding this product — oleic acid may increase how much they lower your blood sugar. No other medication interactions are documented for the ingredients we could check, but that doesn't guarantee none exist with your specific medications.
The bottom line
Scorecard at a glancePartially disclosed formula with some supporting evidence behind its ingredients' uses. Moderate medication interactions have been identified, and safety information is well characterized.
If you're looking at evening primrose oil for cholesterol or heart health, the evidence is modest. If you take diabetes medications, check with your doctor or pharmacist first — oleic acid may boost their effects.
Omega-6 supplements aren't as well studied as food sources, and the balance with omega-3 matters; discuss this product with your own healthcare provider before starting, especially if you're pregnant, nursing, or managing blood sugar or heart health.
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 Apr 22, 2021.
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, straight from the product label.
| Brand | Nature's Way |
|---|---|
| Barcode (UPC) | 033674154168 |
| Net contents | 100 Softgel(s) |
| Market status | On market |
| Date entered into DSLD | Apr 22, 2021 |
| DSLD ID | 243080 |
| Product type | Fat/fatty Acid |
| Supplement form | Softgel Capsule |
| Dietary claims / uses | Nutrient, All Other |
| Intended target group(s) | Adult (18 - 50 Years) |
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 by Nature's Way, sourced from the NIH Dietary Supplement Label Database.
Supplement Facts
| Ingredient | Amount | % DV |
|---|---|---|
| Calories | 5 Calorie(s) | -- |
| Total Fat | 0.5 Gram(s) | 1% |
| Trans Fat | 0 Gram(s) | -- |
| Cholesterol | 0 mg | -- |
| Gamma-Linolenic Acid | 45 mg | -- |
| Omega-6 Fatty Acids | 385 mg | -- |
| Monounsaturated Fat | 0 Gram(s) | -- |
| Saturated Fat | 0 Gram(s) | -- |
| Linoleic Acid | 340 mg | -- |
| Oleic Acid | 30 mg | -- |
| Polyunsaturated Fat | 0 Gram(s) | -- |
| Evening Primrose Oil | 500 mg | -- |
Other ingredients: Gelatin, Glycerin, purified Water
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
Nature's Way Evening Primrose Oil is the highest quality oil-guaranteed to contain 45 mg gamma-linolenic acid (GLA) per serving.
Cold-pressed oil 500 mg per softgel with 45 mg Gamma-Linolenic Acid (GLA)
Formulation
Cold-pressed and unrefined
No chemical solvents, starch, or artificial colors
Precautions
Keep out of reach of children.
Safety sealed with inner seal. Do not use if seal is broken or missing.
If you are pregnant, nursing, or taking any medications, consult a healthcare professional before use.
Storage
Store in a cool, dry place.
Brand IP Statement(s)
Copyright 2020 Distributed by Nature's Way Brands, LLC
General Statements
Please recycle
Nature's Way since 1969
FDA Statement of Identity
Dietary Supplement
Suggested/Recommended/Usage/Directions
Recommendation: Adults swallow 1 softgel 3 to 6 times daily.
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
Evening Primrose by Nature's Way 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 by Nature's Way
These are the 2 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.
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 & interactionsEvening 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 & interactions- › Gamma-Linolenic Acid
- › Omega-6 Fatty Acids
- › Linoleic Acid
Other (inactive) ingredients: Gelatin, Glycerin, Purified Water. These complete the product’s ingredient list but are not active constituents.
Evening Primrose by Nature's Way Drug Interactions
HelloPharmacist Interaction Report
Evening Primrose by Nature's Way may interact with medications through its oleic acid and omega-6 fatty acids content.
The most serious documented interaction is with antidiabetes drugs (blood sugar medications): oleic acid may increase their effects, potentially lowering your blood sugar more than intended.
Read the full breakdown — every affected drug type, severity by severity
Omega-6 fatty acids have no interactions documented in our data. However, we could not check gamma-linolenic acid, monounsaturated fat, linoleic acid, or polyunsaturated fat — we hold no interaction data for these ingredients.
Altogether, these interactions span 86 individual medications. Before you start this product, run your exact blood sugar medications through the checker below if you take any, and talk with your doctor or pharmacist about whether the timing or dose of your diabetes drugs might need adjusting.
Check your own medications below · Editorial policy · How we use AI
Want to check YOUR meds against Evening Primrose?
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 interact with 308 drugs. Click any drug to see the details.
2 of the 2 ingredients in Evening Primrose interact with drugs. Each result below shows which ingredient is responsible. Evening Primrose Oil Oleic Acid
AbciximabReoPro
How Abciximab interacts with Evening Primrose — 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 — 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 — 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 — 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 — 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 — 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 — 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 — 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 — 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 — 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 — 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 — 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 — 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 — 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 — 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 — 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 — 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 — 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 — 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 — 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 — 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 — 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 — 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 — 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 — 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 — 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 — 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 — 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 — 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 — 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 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, from the product label.
Nature's Way
See all Nature's Way products- Name
- Nature's Way Brands, LLC
- City
- Green Bay
- State
- WI
- ZipCode
- 54311
- Phone Number
- 1-800-962-8873
- Web Address
- naturesway.com
Evening Primrose by Nature's Way: Common Questions
Does Evening Primrose by Nature's Way interact with any medications?
How can one product interact with so many drugs?
Where does this information come from?
Can I take evening primrose oil if I'm pregnant or breastfeeding?
Will this help with high cholesterol or heart disease?
What's the difference between the omega-6 in this product and omega-6 from my regular diet?
Are there any side effects I should know about?
What's gamma-linolenic acid, and why is it in here?
I take diabetes medication — is this product safe for me?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Not sure if Evening Primrose 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’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 → Herb & supplement monographOmega-6 Fatty Acids
Omega-6 fatty acids are essential fats your body needs but cannot make on its own, and most people get plenty from everyday foods like vegetable oils, nuts, and seeds. Supplements such as ev...
Read the full Omega-6 Fatty Acids monograph →Sources & How We Checked
Evening Primrose'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 72 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.
Omega-6 Fatty Acids 20 references
- Godley PA. Essential fatty acid consumption and risk of breast cancer. Breast Cancer Res Treat 1995;35:91-5. PubMed
- Newcomer LM, King IB, Wicklund KG, Stanford JL. The association of fatty acids with prostate cancer risk. Prostate 2001;47:262-8. DOI
- Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrate. Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. Washington, DC: National Academy Press, 2005. Available at: http://www.nap.edu/books/03 DOI
- Colter, A. L., Cutler, C., and Meckling, K. A. Fatty acid status and behavioural symptoms of attention deficit hyperactivity disorder in adolescents: a case-control study. Nutr J 2008;7:8. PubMed
- Yamada, T., Strong, J. P., Ishii, T., Ueno, T., Koyama, M., Wagayama, H., Shimizu, A., Sakai, T., Malcom, G. T., and Guzman, M. A. Atherosclerosis and omega-3 fatty acids in the populations of a fishing village and a farming village in Japan. Atheroscler
- Conklin, S. M., Manuck, S. B., Yao, J. K., Flory, J. D., Hibbeln, J. R., and Muldoon, M. F. High omega-6 and low omega-3 fatty acids are associated with depressive symptoms and neuroticism. Psychosom.Med. 2007;69(9):932-934.
- Richardson, A. J., Cyhlarova, E., and Ross, M. A. Omega-3 and omega-6 fatty acid concentrations in red blood cell membranes relate to schizotypal traits in healthy adults. Prostaglandins Leukot.Essent.Fatty Acids 2003;69(6):461-466. PubMed
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