Evening Primrose Oil
Omega/Fatty Acid ·Exploratory record · not publication-reviewed ·Updated July 13, 2026
Rich in gamma-linolenic acid (GLA) for hormonal balance and skin health.
Exploratory record, not a reviewed medical publication.
See the editorial and medical-review policies for the publication gate.
This generated database record has not completed a claim-level review by a qualified human medical reviewer. Bibliography links and evidence labels are not approval. The page remains available for reference and is excluded from search indexing.
What the research says.
A quick, data-only summary. The full evidence, dosing, and sources are below.
Evening Primrose Oil is an omega/fatty acid most often used for hormonal balance, pms relief, skin health. NutriStack rates the overall evidence as moderate. A typical adult dose is 500-1,000 mg daily, commonly taken as cold-pressed evening primrose oil capsules. This profile indexes 18 sources.
The bottom line
Evidence rating moderate. Most-documented uses: hormonal balance, pms relief, skin health. 18 sources indexed (1996–2025), with 0 interaction records on file.
How it works, mechanistically.
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
Dosing & protocol.
What it actually costs.
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.
The same dose, as food.
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.
Full safety detail.
Side effects
- GI upset
- Headache
- Increased bleeding risk
Contraindications
- Blood thinners
- Seizure disorders
- Anesthesia (stop 2 weeks before)
Sources, by evidence tier.
Numbered references. Citations throughout the page link here.
Meta-analyses & systematic reviews
9- 1The Effect of Evening Primrose Oil on Menopausal Symptoms Management: A Systematic Review and Meta-AnalysisPMIDLarki M, Mohammadi S, Makvandi S · J Caring Sci · 2025
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.
- 2Evening Primrose Oil for Menopause Hot Flashes: Systematic Review and Meta-AnalysisPMIDThevi T, De S, Soe HHK · J Menopausal Med · 2024
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.
- 3Evening primrose oil for cervical ripening in term pregnancies: a systematic review and meta-analysisPMIDHemmatzadeh S, Mohammad Alizadeh Charandabi S, Veisy A, Mirghafourvand M · J Complement Integr Med · 2023
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.
- 4A Systematic Review and Meta-Analysis of the Efficacy of Evening Primrose Oil for Mastalgia TreatmentPMIDDefined N et al. · Int J Surg · 2021
Systematic review and meta-analysis examined the efficacy of evening primrose oil for treating breast pain in women
- 5The effect of evening primrose oil on labor induction and cervical ripening: A systematic review and meta-analysisPMIDMoradi M, Niazi A, Heydarian Miri H et al. · Phytotherapy research : PTR · 2021
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
- 6Effect of evening primrose oil supplementation on lipid profile: A systematic review and meta-analysis of randomized clinical trialsPMIDDefined N et al. · Phytother Res · 2020
Systematic review and meta-analysis of RCTs examining EPO supplementation effects on lipid profile markers
- 7Effect of evening primrose oil on menopausal symptoms: a systematic review and meta-analysisSource linkedPMIDMahboubi M · Obstet Gynecol Sci · 2019
- 8Oral evening primrose oil and borage oil for eczemaPMIDBamford JT et al. · Cochrane Database Syst Rev · 2013
Cochrane review assessing oral evening primrose oil and borage oil for eczema treatment, providing the most rigorous assessment of evidence
- 9Evening primrose oil for premenstrual syndromeSource linkedPMIDBudeiri D, Li Wan Po A, Dornan JC · BMJ · 1996
Randomized controlled trials
2- 10Evening primrose oil is effective in atopic dermatitis: a randomized placebo-controlled trialPMIDSenapati S et al. · Indian J Dermatol Venereol Leprol · 2008
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
- 11gamma-Linolenic acid treatment of rheumatoid arthritis. A randomized, placebo-controlled trialPMIDZurier RB, Rossetti RG, Jacobson EW et al. · Arthritis and rheumatism · 1996
Zurier RB, Rossetti RG, Jacobson EW et al.. gamma-Linolenic acid treatment of rheumatoid arthritis. A randomized, placebo-controlled trial. Arthritis and rheumatism. 1996
Reviews & position papers
5- 12Nutrigenetics and Omega-3 and Gamma-Linolenic Acid Intake and Status in Patients with Cancer: A PRISMA Scoping Review of Research Trends and ChallengesPMIDZikic V, Paunovic M, Milovic-Kovacevic M et al. · International journal of molecular sciences · 2025
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
- 13The effect of Oenothera biennis (Evening primrose) oil on inflammatory diseases: a systematic review of clinical trialsPMIDMahboubi M et al. · J Ethnopharmacol · 2024
EPO showed some results in diabetes mellitus, atopic eczema, menopausal hot flashes, and mastalgia through its GLA content and PGE1 production
- 14Evening primrose oil: a comprehensive review of its bioactives, extraction, analysis, oil quality, therapeutic merits, and safetyPMIDFarag MA, Reda A, Nabil M et al. · Food & function · 2023
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
- 15Effect of misoprostol with and without evening primrose (Oenothera biennis) on induction of missed abortionPMIDMahmoodinasab M, Loripoor M, Vazirinejad R et al. · Avicenna journal of phytomedicine · 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
- 16Is evening primrose oil of value in the treatment of premenstrual syndrome?PMIDBudeiri D et al. · Control Clin Trials · 1996
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
Reference material
2- 17Vassilopoulou E, Comotti A, Douladiris N et al.. A systematic review and meta-analysis of nutritional and dietary interventions in randomized controlled trials for skin symptoms in children with atopic dermatitis and without food allergy: An EAACI task force report. Allergy. 2024Source linkedPMID
- 18Bayles B, Usatine R. Evening primrose oil. American family physician. 2009Source linkedPMID
Common questions.
Quick answers about Evening Primrose Oil, drawn from the data on this page.
What is Evening Primrose Oil?
Rich in gamma-linolenic acid (GLA) for hormonal balance and skin health.
What is Evening Primrose Oil used for?
Commonly cited benefits of Evening Primrose Oil include: Hormonal balance; PMS relief; Skin health; Breast tenderness. NutriStack rates the overall evidence as moderate.
What is a typical dose of Evening Primrose Oil?
A typical adult dose of Evening Primrose Oil is 500-1,000 mg daily. The commonly recommended form is Cold-pressed evening primrose oil capsules. These are general ranges, not personalized advice; confirm the right dose with a clinician.
What are the side effects of Evening Primrose Oil?
Reported side effects include gi upset, headache, increased bleeding risk. This is educational information; check with a healthcare professional before use.
How strong is the evidence for Evening Primrose Oil?
NutriStack rates this as Moderate, meaning several aligned RCTs or one large RCT plus supporting reviews. Full tier criteria are at https://nutristackapp.com/methodology/evidence-tiers.
Use this with your stack
Evening Primrose Oil in NutriStack.
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