{"ok":true,"entry":{"slug":"evening-primrose-oil","kind":"supplement","name":"evening primrose oil","aliases":["EPO","Oenothera biennis"],"brands_sg":["NOW Foods","Solgar","Sports Research","Nutricost","Vitacost"],"class":"fatty acid","tags":["womens-health","skin-hair"],"use_for":"nccih: not enough evidence for any health condition","use_after":"daily","use_duration":"the hot-flash trials ran under 6 months","take_with":null,"pros":["generally well tolerated in the trials read","no rise in adverse events across 13 mastalgia trials","skin hydration and barrier improved in volunteers"],"cons":["nccih: no condition has enough evidence behind it","eczema: not shown to help when taken by mouth","breast pain: no different from placebo in 13 trials"],"dose_note":"no studied daily amount could be sourced: nccih gives no dose, and the 13-trial mastalgia meta-analysis and the menopause reviews report products and comparators rather than a common daily amount; for scale, the softgels listed on sg.iherb.com run 500 mg to 1,300 mg","dosage":{"ul":null,"unit":"mg","fda_dv":null,"rda_ai":null,"ul_status":"none_established","population":"general adult","hsa_max_daily":null},"ul_status":"none_established","sg_class":null,"cautions":["pregnancy or breastfeeding — nccih: the evidence is not conclusive","labour induction — long-term safety of that use has not been established","on any medicine — nccih: a provider conversation first","not listed in hsa's annex a/b — hsa says that list is not exhaustive"],"clashes":[{"src":["nccih_epo_meds"],"note":"nccih names no specific drug but asks for a provider conversation first — some herbs and medicines interact in harmful ways","with":"medicines generally"}],"sources":[{"id":"nccih_epo_verdict","url":"https://www.nccih.nih.gov/health/evening-primrose-oil","label":"NCCIH — Evening Primrose Oil: Usefulness and Safety (last updated November 2024), What Have We Learned?","quote":"There's not enough evidence to support the use of evening primrose oil for any health condition.","accessed":"2026-08-27"},{"id":"nccih_epo_eczema","url":"https://www.nccih.nih.gov/health/evening-primrose-oil","label":"NCCIH — Evening Primrose Oil, atopic dermatitis","quote":"Evening primrose oil, taken orally, has not been shown to be helpful for relieving symptoms of atopic dermatitis.","accessed":"2026-08-27"},{"id":"nccih_epo_breast","url":"https://www.nccih.nih.gov/health/evening-primrose-oil","label":"NCCIH — Evening Primrose Oil, breast pain and other conditions","quote":"Evening primrose oil is probably not more effective than a placebo (an inactive substance) for breast pain … There's insufficient evidence to show whether evening primrose oil is helpful for … rheumatoid arthritis, PMS, and menopause symptoms.","accessed":"2026-08-27"},{"id":"nccih_epo_safety","url":"https://www.nccih.nih.gov/health/evening-primrose-oil","label":"NCCIH — Evening Primrose Oil, What Do We Know About Safety?","quote":"Evening primrose oil is probably safe for most adults when taken orally … generally well tolerated. The most common side effects are gastrointestinal symptoms such as abdominal pain, nausea, or diarrhea.","accessed":"2026-08-27"},{"id":"nccih_epo_pregnancy","url":"https://www.nccih.nih.gov/health/evening-primrose-oil","label":"NCCIH — Evening Primrose Oil, pregnancy and breastfeeding","quote":"Evening primrose oil may be safe for use during pregnancy and while breastfeeding, but the evidence is not conclusive … the long-term safety of using evening primrose oil in this way has not been established.","accessed":"2026-08-27"},{"id":"nccih_epo_meds","url":"https://www.nccih.nih.gov/health/evening-primrose-oil","label":"NCCIH — Evening Primrose Oil, medicines","quote":"If you take any type of medicine, talk with your health care provider before using evening primrose oil or other herbal products; some herbs and medicines interact in harmful ways.","accessed":"2026-08-27"},{"id":"nccih_epo_gla","url":"https://www.nccih.nih.gov/health/evening-primrose-oil","label":"NCCIH — Evening Primrose Oil, Background (what is in the oil)","quote":"The oil from evening primrose seeds contains omega-6 fatty acids, including gamma-linolenic acid (GLA).","accessed":"2026-08-27"},{"id":"mastalgia2021","url":"https://europepmc.org/article/PMC/PMC8296106","label":"A Systematic Review and Meta-Analysis of the Efficacy of Evening Primrose Oil for Mastalgia Treatment (Int J Environ Res Public Health 2021) — efficacy","quote":"Thirteen trials with 1752 randomised patients were included. The results showed that EPO has no difference to reduce breast pain compared to topical NSAIDS, danazol, or vitamin E.","accessed":"2026-08-27"},{"id":"mastalgia2021_ae","url":"https://europepmc.org/article/PMC/PMC8296106","label":"EPO mastalgia meta-analysis, IJERPH 2021 — adverse events","quote":"The EPO does not increase adverse events, such as nausea, abdominal bloating, headache or giddiness, increase weight gain, and altered taste compared to a placebo or other treatments.","accessed":"2026-08-27"},{"id":"hotflash2024","url":"https://europepmc.org/article/PMC/PMC11745733","label":"Evening Primrose Oil for Menopause Hot Flashes: Systematic Review and Meta-Analysis (J Menopausal Med 2024)","quote":"The severity of hot flashes was lower when EPO was administered for less than 6 months compared to placebo … The current evidence is insufficient to draw firm conclusions regarding the benefits of EPO in alleviating hot flashes.","accessed":"2026-08-27"},{"id":"inflam2024_skin","url":"https://europepmc.org/article/PMC/PMC10867995","label":"The effect of Oenothera biennis (Evening primrose) oil on inflammatory diseases: a systematic review of clinical trials (BMC Complement Med Ther 2024) — skin outcomes and overall verdict","quote":"Studies in healthy volunteers indicated no significant effect of EPO on epidermal atrophy, nevertheless, positive effects on the skin regarding hydration and barrier function were achieved … contemporary literature is highly heterogeneous","accessed":"2026-08-27"},{"id":"hsa_pr_notlisted","url":"https://file.go.gov.sg/hsa-chp-prohibited-restricted-ing-guidelines.pdf","label":"HSA — Guidelines on Prohibited and Restricted Ingredients in Health Supplements and Traditional Medicines, GL-CHPB-1-012 Rev 001 (Oct 2025), Annex A/B — searched, no row for this ingredient","quote":"The objective of this guideline is to highlight the substances of concern when used in HS and TM and is not meant to be an exhaustive list.","accessed":"2026-08-27"},{"id":"iherb_sg","url":"https://sg.iherb.com/c/evening-primrose-oil","label":"iHerb Singapore — Women's Health > Evening Primrose Oil category (default order, 1 - 47 of 47 results); first 5 distinct brands: NOW Foods, Solgar, Sports Research, Nutricost, Vitacost","quote":"NOW Foods, Super Primrose, 1,300 mg, 120 Softgels … Solgar, Evening Primrose Oil, 1,300 mg, 60 Softgels … Sports Research, Evening Primrose, 120 Softgels … Nutricost, Evening Primrose Oil, 1,300 mg … Vitacost, Evening Primrose Oil","accessed":"2026-08-27"}],"brand_certs":[{"brand":"Sports Research","example":null,"programme":"NSF Certified for Sport","matching_products":0,"brand_total_certified":2}],"updated_at":"2026-08-30T17:59:38.376296+08:00"},"disclaimer":"kozen-x is not a medical device and does not give medical advice. it lists what published sources have written down. absence of a record is not the same as safe."}