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Dietary supplement

Evening Primrose Oil 1,300 mg Ingredients & Drug Interactions

by Ron Teeguarden Nutraceuticals

Softgel Capsule Category: Fat/fatty Acid
Most serious interaction: Moderate
The interaction bottom line Most serious interaction: Moderate

Evening Primrose Oil 1,300 mg is a dietary supplement by Ron Teeguarden Nutraceuticals with 1 active ingredient. Its ingredients are commonly taken for eczema and skin health, pms symptoms, breast pain (mastalgia).Based on those ingredients, 309 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Evening Primrose seed Oil. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

HelloPharmacist Scorecard of Evening Primrose Oil 1,300 mg by Ron Teeguarden Nutraceuticals

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

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 4 of its 4 active ingredients.
  • “Evening Primrose seed Oil” is listed as a grouped ingredient — the label gives one combined amount (1,300 mg) without saying how much of each component you get.

This softgel contains 1,300 mg of evening primrose oil and its component fatty acids. The four active ingredients are oleic acid, palmitic acid, cis-linoleic acid, and gamma-linoleic acid — the same fats naturally present in evening primrose seed oil.

The capsule itself is made from gelatin, glycerin, and water.

Does it work?

Couldn't assess
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
Not assessable

We hold no graded evidence for this product's ingredients for its stated purpose.

Why this rating?
  • The label markets this product for: Evening Primrose Oil supplement.
  • We looked for evidence on: Atopic dermatitis (eczema), Mastalgia, Menopausal symptoms, Premenstrual syndrome (PMS), Skin health, Hormonal balance — and 1 related terms.
  • Our graded evidence for these ingredients doesn't cover that particular purpose.

Oleic acid, one of the main components in this product, is rated possibly effective for high cholesterol (hypercholesterolemia) and coronary heart disease. The other fatty acids in evening primrose oil — cis-linoleic acid and gamma-linoleic acid — have no effectiveness data on file in our records.

We don't hold information on palmitic acid's effectiveness either.

The evidence, ingredient by ingredient Evening Primrose 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 well tolerated and considered safe when consumed in normal dietary amounts. However, concentrated supplements of oleic acid (and by extension, evening primrose oil supplements) haven't been well studied in pregnancy or while breastfeeding.

The safety data available covers only food-level doses, not supplement-level concentrations. If you're pregnant, nursing, or planning to become pregnant, talk with your doctor or pharmacist before taking this product.

Side effects, ingredient by ingredient Evening Primrose 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 any antidiabetes drug (medication that lowers blood sugar), double-check with your doctor or pharmacist before adding this supplement — oleic acid may increase how strongly these drugs work and could lower your blood sugar more than intended.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with no assessable stated purpose. Moderate medication interactions have been identified, and some safety-information gaps remain.

Evening primrose oil may help with cholesterol and heart health based on its oleic acid content, though the evidence is preliminary. The main caution is if you take diabetes medications — this product might strengthen their blood-sugar-lowering effect.

If you're pregnant or breastfeeding, check with your doctor or pharmacist first, since supplement-level doses haven't been studied in those situations. Run your medications through the checker on this page before you start.

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

Assessment coverage: 1 of 4 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Jul 25, 2024.

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 1,300 mg, straight from the product label.

Brand Ron Teeguarden Nutraceuticals
Net contents 60 Softgel(s)
Market status On market
Date entered into DSLD Jul 25, 2024
DSLD ID 316674
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, Dairy Free, Sugar 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 1,300 mg by Ron Teeguarden Nutraceuticals, 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:
1 Softgel Capsule(s)
Maximum serving Sizes:
1 Softgel Capsule(s)
Servings per container
60
IngredientAmount% DV
Calories12 Calorie(s)--
Oleic Acid70 mg--
Total Fat1.5 Gram(s)2%
Palmitic Acid78 mg--
Evening Primrose seed Oil1300 mg--
cis-Linoleic acid925 mg--
gamma-Linoleic acid117 mg--

Other ingredients: Gelatin, Glycerin, Water

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.
Formulation

Contains no sugar, salt, dairy, yeast, wheat, gluten, corn, soy, preservatives, artificial colors or flavors.

Hexane free

Suggested/Recommended/Usage/Directions

Suggested use: As a dietary supplement, adults take one (1) softgel capsule, two (2) or three (3) times daily with meals, or as directed by a health care professional.

Storage

Store in a cool, dry place and away from direct light.

Precautions

Keep out of reach of children.

FDA Statement of Identity

Dietary Supplement

Seals/Symbols

Quality and potency guaranteed

Formula

Our Evening Primrose Oil 1,300 mg is 100% pure cold expeller pressed and hexane free. It is derived from the seeds of the Evening Primrose, a high source of Gamma-Linolenic Acid.

See for yourself

Evening Primrose Oil 1,300 mg by Ron Teeguarden Nutraceuticals label

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

What’s inside

The Ingredients in Evening Primrose Oil 1,300 mg by Ron Teeguarden Nutraceuticals

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size1 Softgel Capsule(s) Dosage formSoftgel Capsule Servings per container60 Amounts shown are per serving.

Evening Primrose seed Oil

Interacts with
234 drugs
1300 mg per serving

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 seed Oil monograph & interactions
  • › Oleic Acid
  • › Palmitic Acid
  • › Cis-Linoleic acid
  • › Gamma-Linoleic acid

Other (inactive) ingredients: Gelatin, Glycerin, Water. These complete the product’s ingredient list but are not active constituents.

Interaction report

Evening Primrose Oil 1,300 mg by Ron Teeguarden Nutraceuticals Drug Interactions

Want to check YOUR meds against Evening Primrose Oil 1,300 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 checker
309Drugs
234 Moderate 75 Minor

Ingredients driving the most interactions

Each ingredient & the kinds of drugs it affects

For each ingredient in Evening Primrose Oil 1,300 mg 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.

Evening Primrose seed Oil5 drug types · 234 drugs

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.

Likelihood Possible Evidence D
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.

Likelihood Possible Evidence D
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.

Likelihood Possible Evidence D
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.

Likelihood Possible Evidence D
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.

Likelihood Possible Evidence D
The maker

Brand information

Manufacturer and brand details for Evening Primrose Oil 1,300 mg, from the product label.

Ron Teeguarden Nutraceuticals

See all Ron Teeguarden Nutraceuticals products
Name
Ron Teeguarden Nutraceuticals
Pharmacist Counseling Corner

Evening Primrose Oil 1,300 mg by Ron Teeguarden Nutraceuticals: Common Questions

Does Evening Primrose Oil 1,300 mg by Ron Teeguarden Nutraceuticals interact with any medications?
Yes. Based on its ingredients, Evening Primrose Oil 1,300 mg has a known interaction with 309 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 1,300 mg contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism 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 actually help with cholesterol or heart health?
Its main active ingredient, oleic acid, is rated possibly effective for high cholesterol and coronary heart disease based on available research. That means there's some promising evidence, but more study is needed to be certain. The other fatty acids in the oil don't have effectiveness data in our records.
Is this safe to take while pregnant or breastfeeding?
Food-level amounts of oleic acid are considered safe during pregnancy and lactation, but this product is a concentrated supplement, and we don't have good safety data for supplement doses in those situations. Talk with your doctor or pharmacist about whether it's right for you.
What exactly is in this product?
It's 1,300 mg of evening primrose oil — a blend of fatty acids including oleic acid, palmitic acid, cis-linoleic acid, and gamma-linoleic acid — packaged in a softgel capsule made from gelatin, glycerin, and water.
Can I take this if I'm on diabetes medication?
The oleic acid in this oil may increase the effect of antidiabetes drugs, potentially lowering your blood sugar more than intended. Check with your doctor or pharmacist about your specific medication before starting, and they can tell you whether you need to monitor your blood sugar more closely.
Are there any side effects I should know about?
We don't have adverse effect data on file for this product. If you experience any unusual symptoms after starting it, stop and talk with your doctor or pharmacist.

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

Not sure if Evening Primrose Oil 1,300 mg is safe with your meds?

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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 1,300 mg label
Sources

Sources & How We Checked

Evening Primrose Oil 1,300 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.

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 34 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 →

Evening Primrose 33 references
  1. Shaw D, Leon C, Kolev S, Murray V. Traditional remedies and food supplements: a 5-year toxicological study (1991-1995). Drug Saf 1997;17:342-56.
  2. Laivuori H, Hovatta O, Viinikka L, et al. Dietary supplementation with primrose oil or fish oil does not change urinary excretion of prostacyclin and thromboxane metabolites in pre-eclamptic women. Prostaglandins Leukot Essent Fatty Acids 1993;49:691-4. PubMed
  3. Dove D, Johnson P. Oral evening primrose oil: its effect on length of pregnancy and selected intrapartum outcomes in low-risk nulliparous women (abstract). J Nurse Midwifery 1999;44:320-4. PubMed
  4. Guivernau M, Meza N, Barja P, Roman O. Clinical and experimental study on the long-term effect of dietary gamma-linolenic acid on plasma lipids, platelet aggregation, thromboxane formation, and prostacyclin production. Prostaglandins Leukot Essent Fatty A PubMed
  5. Cant A, Shay J, Horrobin DF. The effect of maternal supplementation with linoleic and gamma- linolenic acids on the fat composition and content of human milk: a placebo-controlled trial. J Nutr Sci Vitaminol (Tokyo) 1991;37:573-9. PubMed
  6. Keen H, Payan J, Allawi J, et al. Treatment of diabetic neuropathy with gamma-linolenic acid. The gamma-Linolenic Acid Multicenter Trial Group. Diabetes Care 1993;16:8-15.
  7. Blommers J, de Lange-De Klerk ES, Kuik DJ, et al. Evening primrose oil and fish oil for severe chronic mastalgia: a randomized, double-blind, controlled trial. Am J Obstet Gynecol 2002;187:1389-94.. DOI
  8. Cheung KL. Management of cyclical mastalgia in oriental women: pioneer experience of using gamolenic acid (Efamast) in Asia. Aust N Z J Surg 1999;69:492-4..
  9. Das UN. The lipids that matter from infant nutrition to insulin resistance. Prostaglandins Leukot Essent Fatty Acids 2002;67:1-12. PubMed
  10. Wedig KE, Whitsett JA. Down the primrose path: petechiae in a neonate exposed to herbal remedy for parturition. J Pediatr 2008;152:140, 140.e1. PubMed
  11. Ty-Torredes KA. The effect of oral evening primrose oil on bishop score and cervical length amongst term gravidas. Am J Obstet Gynecol. 2006;195(6 Suppl 1):S30.
  12. Moodley J and Norman RJ. Attempts at dietary alteration of prostaglandin pathways in the management of pre-eclampsia. Prostaglandins Leukot Essent Fatty Acids 1989;37(3):145-147. PubMed
  13. Tong M. [Treatment of hyperlipemia with evening primrose oil capsules]. Zhong Xi Yi Jie He Za Zhi. 1988;8:469-71, 452-3.
  14. Holman CP and Bell AF. A trial of evening primrose oil in the treatment of chronic schizophrenia. J Orhtomolecular Psych 1983;12:302-304.
  15. Vaddadi KS. The use of gamma-linolenic acid and linoleic acid to differentiate between temporal lobe epilepsy and schizophrenia. Prostaglandins Med 1981;6(4):375-379. PubMed
  16. Zou L, Harkey MR, and Henderson GL. Effects of herbal components on cDNA-expressed cytochrome P450 enzyme catalytic activity. Life Sci 8-16-2002;71(13):1579-1589. PubMed
  17. Yoon, S., Lee, J., and Lee, S. The therapeutic effect of evening primrose oil in atopic dermatitis patients with dry scaly skin lesions is associated with the normalization of serum gamma-interferon levels. Skin Pharmacol Appl.Skin Physiol 2002;15(1):20- PubMed
  18. Bamford, J. T., Gibson, R. W., and Renier, C. M. Atopic eczema unresponsive to evening primrose oil (linoleic and gamma- linolenic acids). J Am.Acad.Dermatol. 1985;13(6):959-965.
  19. Preece PE, Hanslip JI Gilbert L. Evening primrose oil (Efamol) for mastalgia. In: Horrobin DF. Clinical Uses of Essential Fatty Acids . Montreal, Quebec: Eden;1982.
  20. Parveen, S. Sarwar G. Ali M. Channa G. A. Danazol versus oil of evening primrose in the treatment of mastalgia. Pakistan Journal of Surgery. 2007;23(1):10-13.
  21. Belch JJF, Shaw B, O'Dowd A, et al. Evening primrose oil (Efamol) as a treatment for cold-induced vasospasm (Raynaud's phenomenon). Prog Lipid Res 1986;25:335-40.
  22. Johnson, M., Ostlund, S., Fransson, G., Kadesjo, B., and Gillberg, C. Omega-3/omega-6 fatty acids for attention deficit hyperactivity disorder: a randomized placebo-controlled trial in children and adolescents. J.Atten.Disord. 2009;12(5):394-401. PubMed
  23. Farzaneh F, Fatehi S, Sohrabi MR, Alizadeh K. The effect of oral evening primrose oil on menopausal hot flashes: a randomized clinical trial. Arch Gynecol Obstet 2013;288(5):1075-9. PubMed
  24. Puri BK. The safety of evening primrose oil in epilepsy. Prostaglandins Leukotrienes Essential Fatty Acids 2007;77:101-3. PubMed
  25. Jalloh MA, Gregory PJ, Hein D, et al. Dietary supplement interactions with antiretrovirals: a systematic review. Int J STD AIDS. 2017 Jan;28(1):4-15. PubMed
  26. Osman M, Badawi E. Evening primrose oil reducing serum lithium concentration. Ther Adv Psychopharmacol. 2016 Oct;6(5):343-44. PubMed
  27. Kalati M, Kashanian M, Jahdi F, Naseri M, Haghani H, SHeikhansari N. Evening primrose oil and labour, is it effective? A randomized clinical trial. J Obstet Gynaecol. 2018 Feb 9:1-5.
  28. Sharif SN, Darsareh F. Impact of evening primrose oil consumption on psychological symptoms of postmenopausal women: a randomized double-blinded placebo-controlled clinical trial. Menopause. 2020;27(2):194-198. PubMed
  29. Shahraki AD, Mirhoseini S, Movahedi M, Hajihashemy M, Haghollahi F. Comparative Study of the Effect of Vaginal use of Primrose Oil with Misoprostol on Cervical Preparation of Prim Gravid Women: A Double-blind Clinical Trial. Adv Biomed Res 2023;12:78. PubMed
  30. Shahinfar S, Abedi P, Jahanfar S, Khajehpoor M, Chashmyazdan M. The effect of evening primrose oil on cervical ripening and birth outcomes: A systematic review and meta-analysis. Heliyon 2023;9(2):e13414. PubMed
  31. Mahmoodinasab M, Loripoor M, Vazirinejad R, Aminzadeh F. Effect of misoprostol with and without evening primrose (Oenothera biennis) on induction of missed abortion. Avicenna J Phytomed 2023;13(5):454-462.
  32. Hashemi H, Hasanpoor-Azghady SB, Farahani M, Amiri-Farahani L. Comparison of the effect of vaginal misoprostol and evening primrose oil capsule with misoprostol alone on the consequences of abortion in women with intrauterine fetal death: a randomized cli
  33. Ariana S, Amjadi N, Kazemi SN, Ahmadli Z. The Use of Evening Primrose Oil for Cervical Ripening in Low-Risk Women with Term Pregnancy: A Randomized Double-Blinded Controlled Trial. Complement Med Res 2024;31(3):215-221. PubMed

See these in context on the Evening Primrose 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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