Omega/Fatty Acid ·Moderate evidence ·Reviewed May 2026
Rich in gamma-linolenic acid (GLA) for hormonal balance and skin health.
The bottom line
Evidence rating moderate. Most-documented uses: hormonal balance, pms relief, skin health. 18 sources indexed (1996–2025), with 17 interaction records on file.
Core mechanism
GLA is converted to dihomo-GLA (DGLA) and then to anti-inflammatory prostaglandin E1 (PGE1). Supports healthy estrogen metabolism and skin barrier function.13
Take with food for absorption1,6
Dosing protocol
Provides 80-240 mg GLA per dose. Mild antiplatelet activity.
Ranked by evidence and value.
Real-world pricing across three quality tiers. Assumes Cold-Pressed Evening Primrose Oil.
Assumes 500-1,000 mg/day. Vendor basis: NOW/iHerb, Vitacost, Life Extension, and Amazon marketplace; higher-GLA softgels drive premium pricing. Updated 2026-05-28.
How much you'd eat to match a supplemental dose.
Evening primrose oil is pressed from evening primrose seeds, which are not a normal food source with predictable gamma-linolenic acid dosing.
What to test, the optimal window inside the conventional range, and how long a response takes.
Evening primrose oil (1 to 3 g per day, providing 80 to 240 mg GLA) raises erythrocyte GLA and DGLA.8,1
Most commercial labs offer this in an Omega Check or Essential Fatty Acid panel. Erythrocyte is preferred over plasma for chronic intake.
Where this appears in the symptom-to-supplement map, ranked by relevance.
Evening primrose oil supplies gamma-linolenic acid thought to shift prostaglandin balance in breast tissue and is traditionally used for mastalgia.4
Controlled trials for breast pain are mixed and effects are usually modest; expect a trial of several months rather than quick relief, alongside clinician guidance.
Provides gamma-linolenic acid (GLA) that may feed anti-inflammatory prostaglandin pathways and support barrier function in atopic skin.10,11
Trial data are mixed and largely null; reasonable to try for a few months but not a substitute for prescribed eczema care.
Evening primrose oil supplies gamma-linolenic acid thought to alter prostaglandin balance in breast tissue, though controlled trials for cyclical mastalgia are mixed.4,1
Often needs two to three cycles for any effect, and trial results are inconsistent.
Evening primrose oil supplies gamma-linolenic acid, a precursor that may influence prostaglandin pathways tied to cramping and breast tenderness.1,2
Evidence for period pain is weak; it is better supported for cyclical breast tenderness.
Evening primrose oil provides gamma-linolenic acid that supports skin and mucosal moisture, though dryness-specific evidence is thin.1,2
Often combined with other measures; do not expect a standalone effect.
Provides gamma-linolenic acid feeding prostaglandin pathways that may modestly help breast tenderness, though controlled hot-flash data are weak.11,12
Effects build over weeks; use caution if taking anticoagulants.
GLA-rich oil is often used for cyclic breast tenderness and PMS support.1,4
Results are mixed, but it is a common adjunct.
Provides gamma-linolenic acid intended to support skin barrier lipids, though pooled trials show little consistent benefit for eczema.10,13
Major reviews found no clear benefit; set expectations accordingly.
Evidence-based stacks that include it, with the exact dose and timing each one uses.
Evening Primrose Oil supplies gamma-linolenic acid, a precursor in prostaglandin metabolism that may help cyclical breast tenderness (mastalgia). Evidence for broader premenstrual symptom relief is mixed and considered preliminary.11,12
Evening Primrose Oil provides gamma-linolenic acid (GLA), an omega-6 fatty acid that feeds into skin barrier lipids and anti-inflammatory prostaglandin pathways, on the idea that some people with eczema convert dietary fats to GLA less efficiently. Large reviews have found little consistent benefit for eczema symptoms, so it is included as an optional barrier-support adjunct rather than a proven therapy.11,12
Evening Primrose Oil provides a fat-containing carrier that can improve absorption of fat-soluble compounds like Vitamin D3.
Recommendation: Take Vitamin D3 with Evening Primrose Oil or another fat-containing meal to improve absorption.
Evening Primrose Oil provides a fat-containing carrier that can improve absorption of fat-soluble compounds like Vitamin D2.
Recommendation: Take Vitamin D2 with Evening Primrose Oil or another fat-containing meal to improve absorption.
Evening Primrose Oil provides a fat-containing carrier that can improve absorption of fat-soluble compounds like Vitamin K2.
Recommendation: Take Vitamin K2 with Evening Primrose Oil or another fat-containing meal to improve absorption.
Evening Primrose Oil provides a fat-containing carrier that can improve absorption of fat-soluble compounds like Vitamin K1.
Recommendation: Take Vitamin K1 with Evening Primrose Oil or another fat-containing meal to improve absorption.
Evening Primrose Oil provides a fat-containing carrier that can improve absorption of fat-soluble compounds like Vitamin K2 MK-4.
Recommendation: Take Vitamin K2 MK-4 with Evening Primrose Oil or another fat-containing meal to improve absorption.
Evening Primrose Oil provides a fat-containing carrier that can improve absorption of fat-soluble compounds like Vitamin A.
Recommendation: Take Vitamin A with Evening Primrose Oil or another fat-containing meal to improve absorption.
Evening Primrose Oil provides a fat-containing carrier that can improve absorption of fat-soluble compounds like Vitamin E.
Recommendation: Take Vitamin E with Evening Primrose Oil or another fat-containing meal to improve absorption.
Evening Primrose Oil provides a fat-containing carrier that can improve absorption of fat-soluble compounds like Coenzyme Q10.
Recommendation: Take Coenzyme Q10 with Evening Primrose Oil or another fat-containing meal to improve absorption.
Evening Primrose Oil provides a fat-containing carrier that can improve absorption of fat-soluble compounds like Coenzyme Q10 Ubiquinol.
Recommendation: Take Coenzyme Q10 Ubiquinol with Evening Primrose Oil or another fat-containing meal to improve absorption.
Evening Primrose Oil provides a fat-containing carrier that can improve absorption of fat-soluble compounds like Turmeric/Curcumin.
Recommendation: Take Turmeric/Curcumin with Evening Primrose Oil or another fat-containing meal to improve absorption.
Evening Primrose Oil provides a fat-containing carrier that can improve absorption of fat-soluble compounds like Curcumin Phytosome.
Recommendation: Take Curcumin Phytosome with Evening Primrose Oil or another fat-containing meal to improve absorption.
Evening Primrose Oil provides a fat-containing carrier that can improve absorption of fat-soluble compounds like Astaxanthin.
Recommendation: Take Astaxanthin with Evening Primrose Oil or another fat-containing meal to improve absorption.
Search all 17 interaction records for Evening Primrose Oil →
Numbered references. Citations throughout the page link here.
Meta-analysis of 6 RCTs (450 women) found EPO reduced hot flash duration significantly but reductions in hot flash frequency and intensity were not statistically significant. Evidence grading was moderate to low.
Systematic review found hot flash severity was lower with EPO for less than 6 months compared to placebo, but no significant difference in frequency and duration. Evidence insufficient for firm conclusions.
Meta-analysis of 9 clinical trials found EPO significantly improved Bishop score, reduced cesarean section rate, and shortened duration of first and second stages of labor compared to control.
Systematic review and meta-analysis examined the efficacy of evening primrose oil for treating breast pain in women
Moradi M, Niazi A, Heydarian Miri H et al.. The effect of evening primrose oil on labor induction and cervical ripening: A systematic review and meta-analysis. Phytotherapy research : PTR. 2021
Systematic review and meta-analysis of RCTs examining EPO supplementation effects on lipid profile markers
Cochrane review assessing oral evening primrose oil and borage oil for eczema treatment, providing the most rigorous assessment of evidence
EPO is a safe and effective medicine in management of atopic dermatitis, with statistically significant improvement in severity, inflammation, body surface area involvement, dryness and itch
Zurier RB, Rossetti RG, Jacobson EW et al.. gamma-Linolenic acid treatment of rheumatoid arthritis. A randomized, placebo-controlled trial. Arthritis and rheumatism. 1996
Zikic V, Paunovic M, Milovic-Kovacevic M et al.. Nutrigenetics and Omega-3 and Gamma-Linolenic Acid Intake and Status in Patients with Cancer: A PRISMA Scoping Review of Research Trends and Challenges. International journal of molecular sciences. 2025
EPO showed some results in diabetes mellitus, atopic eczema, menopausal hot flashes, and mastalgia through its GLA content and PGE1 production
Farag MA, Reda A, Nabil M et al.. Evening primrose oil: a comprehensive review of its bioactives, extraction, analysis, oil quality, therapeutic merits, and safety. Food & function. 2023
Mahmoodinasab M, Loripoor M, Vazirinejad R et al.. Effect of misoprostol with and without evening primrose (Oenothera biennis) on induction of missed abortion. Avicenna journal of phytomedicine. 2023
The two most well-controlled studies failed to show beneficial effects for EPO in PMS; on current evidence EPO is of little value in PMS management
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