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📰Read the full Evening Primrose Oil evidence review on GMJ News →Complete clinical article, references and updates on news.gmj.ge. This page is the structured safety summary.⚠ PMS: meta-analysis NEGATIVE [2]
⚠ Mastalgia: UK license WITHDRAWN for lack of efficacy [2]
⚠ Eczema: Cochrane INCONCLUSIVE [2]
⚠ One of the biggest gaps between marketing and evidence in supplements [2]
ℹ️ Not obtained from food. Not applicable — this is not obtained from food in meaningful amounts; supplementation is the practical route.
🔬 Lab interpreter
ℹ️ No validated blood test. There is no established laboratory test to assess status or guide dosing for this ingredient. Clinical response and symptoms are the practical guide.
⚕ For professionals — confirm ranges against your local laboratory.
Clinical verdict
EPO is one of the most popular supplements with the LEAST supporting evidence. PMS: meta-analysis negative. Mastalgia: UK license withdrawn for lack of efficacy. Eczema: Cochrane inconclusive. The GLA→PGE1 biochemistry is real, but clinical translation has failed for most marketed uses. GLA may help diabetic neuropathy and RA [1] [2].
1 How much do I need?
👤 Adults: Specific dosage data under clinical review
👴 Elderly: Specific dosage data under clinical review
🤰 Pregnancy: See guidance
Generally safe early. Avoid third trimester (prostaglandin effects) [1].
👦 Pediatric: See guidance
Limited data. Used in some eczema trials in children [2].
🏃 Athletes: Standard dose
⚖️ Obesity: Standard dose
Fat-soluble compounds may require dose adjustment in obesity.
🩺 Renal: Consult specialist
Dose adjustment may be needed in renal impairment.
🌱 Vegan: Standard dose
How to take
🍽 Timing: TID with meals [1].
💊 With food: With food (fat enhances absorption) [1].
🚫 Avoid: Third trimester. Anticoagulants. Phenothiazines [1].
2 Which form?
| Form | Bioavailability | Vegan | Cost |
|---|---|---|---|
| ['Evening primrose oil capsules', 'common', '500–1,000 mg per capsule. 8–10% GLA [1].'] | Standard | Check label | |
| ['Borage oil', '', 'Higher GLA content (~24%) — alternative GLA source [1].'] | Standard | Check label |
3 Common questions
Does EPO help PMS? ▼
Despite massive popularity for PMS, the meta-analysis found NO convincing benefit [2]. Women who feel it helps may be experiencing placebo response or incidental variation in PMS severity.
Does EPO help breast pain? ▼
Most trials are negative. The UK Medicine Control Agency withdrew its license for mastalgia due to lack of efficacy [2].
Is there anything EPO IS good for? ▼
GLA (from any source) has the best evidence for diabetic neuropathy and possibly RA joint stiffness [1]. But EPO specifically for PMS, mastalgia, and eczema is not well-supported.
4 Clinical evidence
Strong
GLA → DGLA → PGE1 pathway: established biochemistry [1]. HIGH
Moderate
Diabetic neuropathy: some older trials positive for GLA (from EPO). Cochrane review of eczema: insufficient evidence [2]. Rheumatoid arthritis: modest evidence for GLA reducing morning stiffness/joint pain [1]. MODERATE
Insufficient
5 Safety, toxicity & adverse events
Absolute contraindications
✕ Seizure disorder — may lower seizure threshold, especially with phenothiazines
Relative
⚠ Anticoagulants/antiplatelets — bleeding risk
⚠ Discontinue before surgery
⚠ Pregnancy — conflicting data on labour effects
🚩 Red flags
● Patient spending money on EPO for PMS — evidence is negative [2]
● Anticoagulant patient [1]
6 Interactions
Drug interactions
Anticoagulants Moderate
Mechanism: GLA antiplatelet effects. [1]
Effect: Bleeding risk. [1]
Action: Monitor [1].
Supplement synergies
Omega-3 fish oil · 1–2 g EPA+DHA
GLA (omega-6) + EPA (omega-3) for balanced prostaglandin production [1].
GLA (omega-6) + EPA (omega-3) for balanced prostaglandin production [1].
7 Regulatory
United Kingdom: License for mastalgia was WITHDRAWN due to insufficient efficacy evidence [2].
United States: Dietary supplement [1].
8 US supplement products
160
on-market products containing Evening Primrose Oil (NIH DSLD)
Brands carrying Evening Primrose Oil (91)
Click a brand to see its Evening Primrose Oil products.
9 Cite this page
Vancouver: Pkhakadze G. Evening Primrose Oil — safety profile [Internet]. Tbilisi: PHIG; 2026 [cited 2026 Oct 18]. Available from: https://supplement.ge/ingredients/evening-primrose-oil/
APA 7th: Pkhakadze, G. (2026). Evening Primrose Oil — Safety profile. Public Health Institute of Georgia. https://supplement.ge/ingredients/evening-primrose-oil/
📋 Editorial information
Author: Prof. G. Pkhakadze, MD, MPH, PhD
Institution: Public Health Institute of Georgia (PHIG)
Affiliation: David Tvildiani Medical University (DTMU)
First published: January 2026
Last reviewed: 2026-05-29
Next review: April 2027
References: 2 cited sources
COI: SupplementIndex receives no funding from supplement manufacturers. All content independently authored by PHIG.
Process: Systematic literature review
📄 License & reuse
Published under Creative Commons Attribution 4.0 International (CC BY 4.0). You may share and adapt for any purpose with attribution.
Pkhakadze G. "Evening Primrose Oil — Safety Profile." SupplementIndex, PHIG, 2026. https://supplement.ge/ingredients/evening-primrose-oil/ CC BY 4.0.
GP
Prof. G. Pkhakadze, MD, MPH, PhD
Professor of Public Health · Head of Department, DTMU
Editor-in-Chief, Georgian Medical Journal (ISSN 3088-4322)
Chair, Public Health Institute of Georgia · UEMS Public Health Section
Educational and public health purposes. CC BY 4.0. Consult your healthcare provider before starting any supplement. Corrections: info@accreditation.ge. Publisher: PHIG