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Dietary supplement

Evening Primrose Oil Ingredients & Drug Interactions

by Barlean's

Evening Primrose Oil label
See full label image
Softgel Capsule Category: Fat/fatty Acid
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 30, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Evening Primrose Oil 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

The interaction bottom line Most serious interaction: Moderate

Evening Primrose Oil is a dietary supplement by Barlean's with 3 active ingredients. Its ingredients are commonly taken for heart health, healthy cooking fat, skin moisturizing.Based on those ingredients, 86 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Oleic Acid. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Evening Primrose Oil by Barlean's

Ask about any prescription or over-the-counter medication and we check it for interactions with Evening Primrose Oil by Barlean's — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
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HelloPharmacist Scorecard of Evening Primrose Oil by Barlean's

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.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 30, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 5 of its 5 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

Barlean's Evening Primrose Oil is a softgel containing five active ingredients: polyunsaturated fat, monounsaturated fat, gamma-linolenic acid, linoleic acid, and oleic acid. These are all fatty acids naturally present in evening primrose seed oil.

The product also contains organic evening primrose oil itself as an inactive ingredient and a softgel capsule shell.

Does it work?

Moderate evidence
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed

This product doesn't appear to be marketed for a specific use, so we graded Oleic Acid's overall clinical evidence instead.

Moderate

Some clinical evidence supports Oleic Acid for:

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.
  • Since the label doesn't commit to one use, we graded the ingredient's overall clinical evidence instead.
  • On file: Coronary heart disease (CHD) — rated "Possibly Effective" (Natural Medicines).
  • On file: Hypercholesterolemia — rated "Possibly Effective" (Natural Medicines).

The evidence we hold covers only oleic acid, one of the five actives. Oleic acid is rated possibly effective for high cholesterol (hypercholesterolemia) and coronary heart disease (CHD).

We don't have effectiveness ratings on file for the other four ingredients in this product, so we can't speak to what the full evening primrose oil formula may do beyond what oleic acid alone is shown to support.

The evidence, ingredient by ingredient Oleic Acid

How safe is it?

Some data gaps
Safety Information · database check
Some gaps

Safety data exists for these ingredients, but with some important gaps.

Why this rating?
  • We hold adverse-effect (side-effect) data for 0 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Oleic acid from food sources — like olive oil — is generally recognized as safe in normal amounts. However, the safety data for concentrated oleic acid supplements during pregnancy and breastfeeding is limited.

If you're pregnant, nursing, or planning pregnancy, talk with your doctor or pharmacist about whether this product is right for you. We don't have adverse effects listed for oleic acid in our data.

Side effects, ingredient by ingredient Oleic Acid

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Oleic Acid.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: diabetes medications.
  • For scale: 86 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

If you take antidiabetes drugs (blood sugar medications), this product deserves a conversation with your doctor or pharmacist — oleic acid may increase their effect. For the other four active ingredients in this product, we hold no interaction data, so we can't flag any drug types to watch for them.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with some supporting evidence behind its ingredients' uses. Moderate medication interactions have been identified, and some safety-information gaps remain.

If you're looking to support cholesterol levels or heart health, the oleic acid in this product has some research behind it. But if you take antidiabetes medication, check with your doctor or pharmacist first — oleic acid may strengthen how well those drugs work.

Anyone pregnant or nursing should discuss this supplement with their healthcare provider before starting.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 1 of 5 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Mar 24, 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

At a glance

General information

Key facts about Evening Primrose Oil, straight from the product label.

Brand Barlean's
Barcode (UPC) 705875100175
Net contents 60 Softgel(s)
Market status On market
Date entered into DSLD Mar 24, 2020
DSLD ID 215550
Product type Fat/fatty Acid
Supplement form Softgel Capsule
Dietary claims / uses Nutrient, All Other
Intended target group(s) Adult (18 - 50 Years), Gluten Free
From the label
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 by Barlean's, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
2 Softgel(s)
Maximum serving Sizes:
2 Softgel(s)
Servings per container
30
UPC/BARCODE
705875100175
IngredientAmount% DV
Calories25 Calorie(s)--
Total Fat2.5 Gram(s)3%
Polyunsaturated Fat1.5 Gram(s)--
Monounsaturated Fat1 Gram(s)--
Gamma-Linolenic Acid234 mg--
Linoleic Acid1846 mg--
Oleic Acid130 mg--

Other ingredients: organic Evening Primrose Oil, Softgel

Tap any ingredient to jump to its full detail below.

Label statements
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

Barlean's Evening Primrose Oil: Nourish Your Body with GLA Evening Primrose Oil is revered as a source of Gamma-Linolenic Acid (GLA). GLA is created in the body from essential healthy fats like those found in flaxseed. In some people, however, GLA is not adequately produced. For those people, Barlean's Evening Primrose Oil offers a direct source.

Pure & Unrefined

Formulation

FreshTech Patented Softgel Technology

Product of U.S.A.

Gluten Free Non-GMO

General Statements

Learn more about a Pathway to a Better Life:

From our family to yours Barbara Barlean David Barlean Bruce Barlean

ESTD 1989 Barlean's Pathway To A Better Life

FDA Statement of Identity

Evening Primrose Oil Supplement

Brand IP Statement(s)

Patents: See www.barleans.com/patents

Suggested/Recommended/Usage/Directions

Suggested Use: 2 Softgels per day.

Storage

Keep bottle tightly closed. Store in a cool, dry place, out of reach of children.

Precautions

Store in a cool, dry place, out of reach of children.

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Evening Primrose Oil by Barlean's label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Evening Primrose Oil label

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)
What’s inside

The Ingredients in Evening Primrose Oil by Barlean's

These are the 3 active ingredients this product is made of. Select any to open its full monograph.

Serving size2 Softgel(s) Dosage formSoftgel Capsule Servings per container30 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

234 mg per serving

Linoleic Acid

1846 mg per serving

Oleic Acid

Interacts with
86 drugs
130 mg per serving

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 & interactions

Other (inactive) ingredients: Organic Evening Primrose Oil, Softgel. These complete the product’s ingredient list but are not active constituents.

Interaction report

Evening Primrose Oil by Barlean's Drug Interactions

Want to check YOUR meds against Evening Primrose Oil?

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 checker
86Drugs
86 Moderate

Ingredients driving the most interactions

Oleic Acid 86

Individual Drug Interactions

The ingredients in Evening Primrose Oil interact with 86 drugs. Click any drug to see the details.

1 of the 3 ingredients in Evening Primrose Oil interact with drugs. Each result below shows which ingredient is responsible. Oleic Acid

Each ingredient & the kinds of drugs it affects

For each ingredient in Evening Primrose Oil with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

Oleic Acid1 drug type · 86 drugs

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.

Likelihood Possible Evidence B
Oleic Acid full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Evening Primrose Oil, from the product label.

Barlean's

See all Barlean's products
Name
Barlean's
City
Ferndale
State
WA
ZipCode
98248
Phone Number
800-445-3529
Web Address
barleans.com
Pharmacist Counseling Corner

Evening Primrose Oil by Barlean's: Common Questions

Does Evening Primrose Oil by Barlean's interact with any medications?
Yes. Based on its ingredients, Evening Primrose Oil has a known interaction with 86 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Evening Primrose Oil contains 3 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Does evening primrose oil from Barlean's actually work?
We have effectiveness evidence only for oleic acid, one of the five active ingredients — it's rated possibly effective for high cholesterol and coronary heart disease. We don't have data on file for the other four ingredients, so we can't tell you whether the full formula works for other uses.
Can I take this if I'm pregnant or breastfeeding?
The safety data for concentrated evening primrose oil supplements during pregnancy and breastfeeding is limited. Talk with your doctor or pharmacist — they can advise you based on your individual situation.
What is oleic acid, and why is it in here?
Oleic acid is a fatty acid naturally found in evening primrose oil. Research suggests it may help with cholesterol and heart health, which is why it's a notable component of this supplement.
Will this product lower my blood sugar if I take diabetes medication?
Oleic acid in this product may increase how well antidiabetes drugs work, potentially lowering your blood sugar more than expected. If you take any diabetes medication, check with your doctor or pharmacist before starting — they may need to monitor your blood sugar more closely or adjust your dose.
Are there any fillers or other ingredients I should know about?
The inactive ingredients are organic evening primrose oil and the softgel capsule itself. The five active ingredients are the fatty acids that make up the oil.

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

Not sure if Evening Primrose Oil is safe with your meds?

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Ask a pharmacist

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.

Evening Primrose Oil label
Go deeper

The Full Monographs Behind Evening Primrose Oil’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Oleic Acid

Interacts with 86 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 is widely viewed as a healthier replace...

Read the full Oleic Acid monograph →
Sources

Sources & How We Checked

Evening Primrose Oil'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.

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 1 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 1 reference
  1. 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

See these in context on the Oleic Acid monograph →

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

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