Evening Primrose Oil

Purported Benefits, Side Effects & More

Evening Primrose Oil

Purported Benefits, Side Effects & More
Evening Primrose Oil

Common Names

  • Evening primrose oil
  • Night willow herb
  • Fever plant
  • King's cure-all

For Patients & Caregivers

Tell your healthcare providers about any dietary supplements you’re taking, such as herbs, vitamins, minerals, and natural or home remedies. This will help them manage your care and keep you safe.

What is it?

Evening primrose is a plant that was used by Native Americans to heal wounds, bruises, and to soothe swollen skin. They would eat the leaves to help with sore throats and stomach issues.

Evening primrose oil supplements come as softgels, capsules, and liquids. It’s also added to creams and ointments that you can put on your skin.

What are the potential uses and benefits?

Evening primrose oil is used to:

  • Treat dermatitis (a type of eczema that makes your skin red, itchy, and swollen)
  • Relieve pain caused by arthritis
  • Treat breast pain
  • Treat menstrual symptoms (symptoms caused by your monthly period) such as bloating and headaches
  • Treat symptoms caused by menopause (permanent end of menstrual cycles) such as hot flashes
  • Treat nerve damage caused by diabetes

Evening primrose oil also has other uses but they haven’t been studied by doctors to see if they work.

Talk with your healthcare provider before taking evening primrose oil supplements. They can interact with some medications and affect how they work. For more information, read the “What else do I need to know?” section below.

What are the side effects?

Side effects of using evening primrose oil may include:

  • Stomach pain
  • Nausea (feeling like you’re going to throw up)
  • Headaches
What else do I need to know?
  • Talk with your healthcare provider if you’re taking blood thinners such as warfarin (Coumadin®, Jantoven®). Evening primrose oil may increase your risk of bleeding.
  • Talk with your healthcare provider if you’re taking medication to lower your blood pressure. Evening primrose oil can increase your blood pressure.
  • Talk to your healthcare provider if you’re taking the HIV medication lopinavir (Kaletra®).  Evening primrose oil may affect how it works.
  • Talk with your healthcare provider if you’re pregnant or breastfeeding. It may increase the risk of complications.

For Healthcare Professionals

Scientific Name
Oenothera biennis
Clinical Summary

Derived from the plant Oenothera biennis, evening primrose oil is used for rheumatoid arthritis, premenstrual syndrome, eczema, fatigue, diabetic neuropathy, and mastalgia. The mucilaginous stem and leaf juices have been used as a poultice to treat minor bruises and wounds, and soothe skin inflammation (25). Evening primrose oil is thought to improve skin moisture and reduce transepidermal water loss (26). It is also among the popular natural products used to relieve menopausal symptoms (27) (28). In vitro, evening primrose oil demonstrates anti-inflammatory activity (29) and inhibits platelet aggregation (6) (7). In animal models, it exerts anti-angiogenic, anti-inflammatory, and anti-arthritic effects (30), and improved cardiac recovery after myocardial infarction (31).

Human studies on whether evening primrose oil is helpful for skin conditions are limited and mixed. Small trials suggest benefit in atopic dermatitis (18) (25) (32), but other analyses did not find evening primrose oil or borage oil effective for eczema (23) (33). In acne patients treated with oral isotretinoin, evening primrose oil may improve xerotic cheilitis (34). It may also reduce 5-azacitidine-induced skin reactions in patients with myelodysplastic syndrome (19). Other preliminary data suggest benefit in some lipid profiles (53) (56), rheumatoid arthritis symptoms (21), ulcerative colitis (35) (36), or for ocular surface diseases such as dry eye (37) (38), but early studies in diabetic neuropathy were equivocal (39). More recently, gamma-linolenic acid (GLA) derived from evening primrose oil was found noninferior to alpha-lipoic acid for reducing pain in patients with diabetic neuropathy (57). In multiple sclerosis patients, evening primrose oil may improve fatigue and quality of life (54), and along with hemp seed and a diet high in antioxidants, it may improve clinical and immunological parameters (40) (41) (42).

Additional data indicate that supplementation with vitamin E and evening primrose oil reduced cyclical mastalgia (20), but other analyses did not find improvements in breast pain (1) (43) or premenstrual syndrome (22). Evening primrose oil may improve quality of life and decrease hot flash intensity in menopausal women (44), although other data suggest that behavioral/lifestyle approaches such as exercise provide better relief (28). In postmenopausal women, it improved related psychological symptoms (55), but more study is needed to confirm these effects.

Studies in cancer patients are quite limited, with one trial involving liver cancer patients that showed no effect on tumor size or survival (45), and another that suggested GLA may be an effective adjunctive therapy for breast cancer (4). Although evening primrose oil does not have intrinsic estrogenic properties, some commercial products combine evening primrose oil with phytoestrogens. Therefore, patients with hormone-sensitive cancers should use evening primrose oil products with caution.

Purported Uses and Benefits
  • Dermatitis
  • Arthritis
  • Mastalgia
  • PMS
  • Menopausal symptoms
  • Diabetic neuropathy
Mechanism of Action

Evening primrose oil is rich in the omega-6 fatty acid GLA, which can be converted directly to the prostaglandin precursor dihomo-GLA (DGLA) (2) (3). Administration of the oil may benefit individuals unable to metabolize cis-linolenic acid to GLA, producing subsequent intermediates of metabolic significance including prostaglandins (2) (3).

In vitro, long-chain fatty alcohols such as hexacosanol, tetracosanol, docosanol, and octocosanol demontrated anti-inflammatory activity (29). In animal models, benefits on cardiac recovery after myocardial infarction were attributed to its hypocholesterolemic effect and indirect influence on prostaglandins and cytokine synthesis (31). In arthiritis models, evening primrose oil normalized body weight, angiopoietin-1, and TNF-alpha levels, and reduced malondialdehyde levels, synovial hyperplasia, and inflammatory cell invasion in joint tissues (30).

In patients with multiple sclerosis, evening primrose oil accelerates anti-inflammatory responses and prevents pro-inflammatory cytokine production while helping to maintain fatty acid membranes and optimizing balance between saturated and unsaturated fatty acids (40). Increases in plasma GLA and its metabolite DGLA seen with evening primrose oil supplementation has correlated with clinical improvements in atopic dermatitis (32) and produced dose-dependent effects on serum fatty acid levels and eczema severity scores (25). Inhibition of cheilitis is attributed to GLA’s effects on stratum corneum maturation, differentiation, and preservation of its permeability barrier (34). Antiplatelet and anticoagulant effects are likely related to decreased thromboxane B2 synthesis induced by evening primrose oil (46) (47).

  • Pregnant women should not take evening primrose oil due to increased risk of pregnancy complications (8) (48).
  • Patients with hormone-sensitive cancers should use evening primrose oil products with caution, because even though it does not possess estrogenic properties on its own, some commercial evening primrose oil products may contain other phytoestrogen ingredients.
Adverse Reactions

Minor: abdominal pain, indigestion, nausea, softening of stools, and headaches (25).
Labor abnormalities: When used to shorten gestation and length of labor, increased incidences of prolonged membrane rupture, oxytocin augmentation, arrest of descent, and vacuum extraction (8) (48).  

Case reports
Petechiae and ecchymoses: Observed in a newborn whose mother used raspberry leaf tea and evening primrose oil vaginally and orally 1 week before childbirth (12).
Lipoid pneumonia: In a 50-year-old woman following chronic use of evening primrose oil, caused by aspiration of lipid particles into the lungs (24).

Herb-Drug Interactions

Anticoagulants/Antiplatelets: May have additive effects and increase bleeding risk (46) (49). In a small study of humans on several months of supplementation with GLA from evening primrose oil, a significant increase in bleeding time was observed in 9 of 12 patients (47). Evening primrose oil is about 10% GLA (52).

Blood pressure medications: Although there are no interactions reported with blood pressure medications, evening primrose oil was identified as being among supplements that may increase both systolic and diastolic blood pressures, with a clinically meaningful difference for systolic blood pressure in a large population-based study (50).

Antiretrovirals: In humans, evening primrose oil significantly increases the levels of antiretroviral drugs and may increase the risk of adverse effects (51).

Dosage (OneMSK Only)
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  2. Belch JJ, Hill A. Evening primrose oil and borage oil in rheumatologic conditions. Am J Clin Nutr 2000;71:352S-6S.
  3. Tyler, V. Herbs of Choice, the Therapeutical Use of Phytomedicinals. Binghamton: Pharmaceutical Press; 1994.
  4. Kenny FS, et al. Gamma linolenic acid with Tamoxifen as primary therapy in breast cancer. Int J Cancer 2000; 85:643-8.
  5. Schirmer MA, Phinney SD. Gamma-linolenate reduces weight regain in formerly obese humans. J Nutr. Jun 2007;137(6):1430-1435.
  6. De La Cruz JP, Martin-Romero M, Carmona JA, et al. Effect of evening primrose oil on platelet aggregation in rabbits fed an atherogenic diet. Thromb Res. Jul 1 1997;87(1):141-149.
  7. 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 Acids. Nov 1994;51(5):311-316.
  8. Dove D, Johnson P. Oral evening primrose oil: its effect on length of pregnancy and selected intrapartum outcomes in low-risk nulliparous women. J Nurse Midwifery. 1999 May-Jun;44(3):320-4.
  9. Holman CP, et al. A trial of evening primrose oil in the treatment of chronic schizophrenia. J Orthomolecular Psychiatry 1983;12:302-4.
  10. Newall C. Herbal Medicines, A Guide for Health Care Professionals. London: Pharmaceutical Press; 1997.
  11. Martens-Lobenhoffer J, Meyer FP. Pharmacokinetic data of gamma-linoleic acid in healthy volunteers after the administration of evening primrose oil (Epogam). Int J Clin Pharmacology Therapeutics 1998;36:363-6.
  12. Wedig KE, Whitsett JA. Down the primrose path: petechiae in a neonate exposed to herbal remedy for parturition. J Pediatr. Jan 2008;152(1):140, 140 e141.
  13. Zurier RB, et al. Gamma-linolenic acid treatment of rheumatoid arthritis. A randomized, placebo-controlled trial. Arthritis Rheum 1996;39:1808-17.
  14. Budeiri D, et al. Is evening primrose oil of value in the treatment of premenstrual syndrome? Control Clin Trials 1996;17:60-8.
  15. Keen H, et al. Treatment of diabetic neuropathy with gamma-linolenic acid. Diabetes Care 1993;16:8-15.
  16. Pye JK, et al. Clinical experience of drug treatment for mastalgia. Lancet 1985;2:373-7.
  17. Blommers J, et al. Evening primrose oil and fish oil for severe chronic astalgia: a randomized, double-blind, controlled trial. Am J Obstet Gynecol. 2002 Nov;187(5):1389-94.
  18. Senapati S, Banerjee S, Gangopadhyay DN. Evening primrose oil is effective in atopic dermatitis: a randomized placebo-controlled trial. Indian J Dermatol Venereol Leprol. 2008 Sep-Oct;74(5):447-52.
  19. Platzbecker U, Aul C, Ehninger G, Giagounidis A. Reduction of 5-azacitidine induced skin reactions in MDS patients with evening primrose oil. Ann Hematol. 2010 Apr;89(4):427-8.
  20. Pruthi S, Wahner-Roedler DL, Torkelson CJ, et al. Vitamin E and evening primrose oil for management of cyclical mastalgia: a randomized pilot study. Altern Med Rev. 2010 Apr;15(1):59-67.
  21. Cameron M, Gagnier JJ, Chrubasik S. Herbal therapy for treating rheumatoid arthritis. Cochrane Database Syst Rev. 2011 Feb 16;(2):CD002948.
  22. Dante G, Facchinetti F. Herbal treatments for alleviating premenstrual symptoms: a systematic review. J Psychosom Obstet Gynaecol. 2011 Mar;32(1):42-51.
  23. Bamford JT, Ray S, Musekiwa A, et al. Oral evening primrose oil and borage oil for eczema. Cochrane Database Syst Rev. 2013 Apr 30;4:CD004416. 
  24. Rabahi MF, Ferreira AA, Madeira JG, Galvao PM, Pinto SA. Lipoid pneumonia secondary to long-term use of evening primrose oil. J Bras Pneumol. 2010 Oct;36(5):657-61.
  25. Chung BY, Kim JH, Cho SI, et al. Dose-dependent effects of evening primrose oil in children and adolescents with atopic dermatitis. Ann Dermatol. Aug 2013;25(3):285-291.
  26. Muggli R. Systemic evening primrose oil improves the biophysical skin parameters of healthy adults. Int J Cosmet Sci. Aug 2005;27(4):243-249.
  27. Ohn Mar S, Malhi F, Syed Rahim SH, et al. Use of Alternative Medications for Menopause-Related Symptoms in Three Major Ethnic Groups of Ipoh, Perak, Malaysia. Asia Pac J Public Health. Nov 2015;27(8 Suppl):19s-25s.
  28. Gentry-Maharaj A, Karpinskyj C, Glazer C, et al. Use and perceived efficacy of complementary and alternative medicines after discontinuation of hormone therapy: a nested United Kingdom Collaborative Trial of Ovarian Cancer Screening cohort study. Menopause. Apr 2015;22(4):384-390.
  29. Montserrat-de la Paz S, Garcia-Gimenez MD, Angel-Martin M, et al. Long-chain fatty alcohols from evening primrose oil inhibit the inflammatory response in murine peritoneal macrophages. J Ethnopharmacol. 2014;151(1):131-136.
  30. El-Sayed RM, Moustafa YM, El-Azab MF. Evening primrose oil and celecoxib inhibited pathological angiogenesis, inflammation, and oxidative stress in adjuvant-induced arthritis: novel role of angiopoietin-1. Inflammopharmacology. Oct 2014;22(5):305-317.
  31. Abo-Gresha NM, Abel-Aziz EZ, Greish SM. Evening primrose oil ameliorates platelet aggregation and improves cardiac recovery in myocardial-infarct hypercholesterolemic rats. Int J Physiol Pathophysiol Pharmacol. 2014;6(1):23-36.
  32. Simon D, Eng PA, Borelli S, et al. Gamma-linolenic acid levels correlate with clinical efficacy of evening primrose oil in patients with atopic dermatitis. Adv Ther. Feb 2014;31(2):180-188.
  33. Madhok V, Futamura M, Thomas KS, et al. What’s new in atopic eczema? An analysis of systematic reviews published in 2012 and 2013. Part 2. Treatment and prevention. Clin Exp Dermatol. Jun 2015;40(4):349-354.
  34. Park KY, Ko EJ, Kim IS, et al. The effect of evening primrose oil for the prevention of xerotic cheilitis in acne patients being treated with isotretinoin: a pilot study. Ann Dermatol. Dec 2014;26(6):706-712.
  35. Greenfield SM, Green AT, Teare JP, et al. A randomized controlled study of evening primrose oil and fish oil in ulcerative colitis. Aliment Pharmacol Ther. Apr 1993;7(2):159-166.
  36. Ng SC, Lam YT, Tsoi KK, et al. Systematic review: the efficacy of herbal therapy in inflammatory bowel disease. Aliment Pharmacol Ther. Oct 2013;38(8):854-863.
  37. Jalbert I. Diet, nutraceuticals and the tear film. Exp Eye Res. Dec 2013;117:138-146.
  38. Kokke KH, Morris JA, Lawrenson JG. Oral omega-6 essential fatty acid treatment in contact lens associated dry eye. Cont Lens Anterior Eye. Jun 2008;31(3):141-146.
  39. Rock E, DeMichele A. Nutritional approaches to late toxicities of adjuvant chemotherapy in breast cancer survivors. J Nutr. Nov 2003;133(11 Suppl 1):3785s-3793s.
  40. Rezapour-Firouzi S, Arefhosseini SR, Ebrahimi-Mamaghani M, et al. Erythrocyte membrane fatty acids in multiple sclerosis patients and hot-nature dietary intervention with co-supplemented hemp-seed and evening-primrose oils. Afr J Tradit Complement Altern Med. 2013;10(6):519-527.
  41. Rezapour-Firouzi S, Arefhosseini SR, Mehdi F, et al. Immunomodulatory and therapeutic effects of Hot-nature diet and co-supplemented hemp seed, evening primrose oils intervention in multiple sclerosis patients. Complement Ther Med. Oct 2013;21(5):473-480.
  42. Rezapour-Firouzi S, Arefhosseini SR, Ebrahimi-Mamaghani M, et al. Activity of liver enzymes in multiple sclerosis patients with Hot-nature diet and co-supplemented hemp seed, evening primrose oils intervention. Complement Ther Med. Dec 2014;22(6):986-993.
  43. Kataria K, Dhar A, Srivastava A, et al. A systematic review of current understanding and management of mastalgia. Indian J Surg. Jun 2014;76(3):217-222.
  44. Farzaneh F, Fatehi S, Sohrabi MR, et al. The effect of oral evening primrose oil on menopausal hot flashes: a randomized clinical trial. Arch Gynecol Obstet. Nov 2013;288(5):1075-1079.
  45. van der Merwe CF, Booyens J, Joubert HF, et al. The effect of gamma-linolenic acid, an in vitro cytostatic substance contained in evening primrose oil, on primary liver cancer. A double-blind placebo controlled trial. Prostaglandins Leukot Essent Fatty Acids. Jul 1990;40(3):199-202.
  46. Norred CL, Brinker F. Potential coagulation effects of preoperative complementary and alternative medicines. Altern Ther Health Med. Nov-Dec 2001;7(6):58-67.
  47. Guivernau M, Meza N, Barja P, et al. 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 Acids. Nov 1994;51(5):311-316.
  48. Dante G, Bellei G, Neri I, et al. Herbal therapies in pregnancy: what works? Curr Opin Obstet Gynecol. Apr 2014;26(2):83-91.
  49. Riaz A, Khan RA, Ahmed SP. Assessment of anticoagulant effect of evening primrose oil. Pak J Pharm Sci. Oct 2009;22(4):355-359.
  50. McCarty CA, Berg RL, Rottscheit CM, et al. The use of dietary supplements and their association with blood pressure in a large Midwestern cohort. BMC Complement Altern Med. 2013;13:339.
  51. Jalloh MA, Gregory PJ, Hein D, Risoldi Cochrane Z, Rodriguez A. Dietary supplement interactions with antiretrovirals: a systematic review. Int J STD AIDS. 2017 Jan;28(1):4-15.
  52. Chung S, Kong S, Seong K, et al. Gamma-linolenic acid in borage oil reverses epidermal hyperproliferation in guinea pigs. J Nutr. Oct 2002;132(10):3090-3097.
  53. Khorshidi M, Zarezadeh M, Moradi Moghaddam O, et al. Effect of evening primrose oil supplementation on lipid profile: A systematic review and meta-analysis of randomized clinical trials. Phytother Res. May 22 2020.
  54. Majdinasab N, Namjoyan F, Taghizadeh M, et al. The effect of evening primrose oil on fatigue and quality of life in patients with multiple sclerosis. Neuropsychiatr Dis Treat. 2018;14:1505-1512.
  55. 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. Feb 2020;27(2):194-198.
  56. Khorshidi M, Zarezadeh M, Moradi Moghaddam O, et al. Effect of evening primrose oil supplementation on lipid profile: A systematic review and meta-analysis of randomized clinical trials. Phytother Res. Oct 2020;34(10):2628-2638.
  57. Won JC, Kwon HS, Moon SS, et al. γ-Linolenic Acid versus α-Lipoic Acid for Treating Painful Diabetic Neuropathy in Adults: A 12-Week, Double-Placebo, Randomized, Noninferiority Trial. Diabetes Metab J. Aug 2020;44(4):542-554.
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