Botanical Name: Oenothera
The seeds are pressed for their oil, which is high in the n-6 (omega-6) fatty acids, linoleic acid (LA) and gamma-linolenic acid (GLA).
- Supplies the Body with Omega-6 Fatty Acids [1-5]
- Atopic Dermatitis (Eczema) in Infants, oral doses of evening primrose oil [6-8]
- Arthritis [9-13]
- Atopic Dermatitis (Eczema), oral consumption of evening primrose oil appears to produce conflicting results; however, evening primrose oil applied topically or added to bath water may be effective [14-26]
- Breast Pain (Mastalgia) [27-36]
- Chronic Kidney Disease, treatment of skin symptoms 
- Diabetic Neuropathy [38-39]
- Dry Eyes due to Contact Lenses, oral dose of evening primrose oil 
- Inflammatory Bowel Disease (IBD) 
- Lowers Cholesterol 
- Menopausal Complaints, a blend containing evening primrose oil / damiana / ginseng / royal jelly may be effective [43-45]
- Mild to Moderate Hypertension 
- Multiple Sclerosis, a blend of evening primrose oil / hemp seed oil 
- Nail Health 
- Raynaud’s Phenomenon 
- Sjogren’s Syndrome [50-52]
- Tardive Dyskinesia 
- Type 1 Diabetes, improving fatty acid counts 
- Type 2 Diabetes, improves fatty acid counts in adults and children [55-56]
- ADHD (Attention Deficit Hyperactivity Disorder); however, evening primrose oil in combination with zinc may be more effective [57-59]
- Asthma, evening primrose oil in combination with fish oil may also not be effective [60-62]
- Breast Cyst 
- Breast Milk, improving fatty acid counts [64-67]
- Cellulite 
- Chronic Fatigue Syndrome 
- Cystic Fibrosis 
- Decreases Natural Killer Cell Activity 
- Heart Health 
- Hepatitis B 
- Hypertriglyceridemia 
- Liver Cancer 
- Osteoporosis (Bone Density), when evening primrose oil is used independently 
- Pre-eclampsia [77-79]
- Premenstrual Syndrome (PMS) [80-83]
- Psoriasis, evening primrose oil in combination with fish oil 
- Peptic Ulcers 
- Weight Loss 
No Clinical Research:All other conditions.
- Gastrointestinal Upset
- Use caution or contact a licensed healthcare practitioner if you have schizophrenia, seizures, or epilepsy because there have been reports of evening primrose oil lowering seizure threshold, but these reports may have actually been caused by other medications.
- There have been cases of evening primrose oil causing lipid pneumonia, thrombosis (blood clots), inflammation, immunosuppression, an increase in the risk of bleeding, petechiae (red to purple spots in the skin).
There is not enough research on the use of supplements containing evening primrose oil during pregnancy and breast-feeding, so consult a licensed healthcare practitioner before use or avoid use. Evening primrose oil is commonly used during breast-feeding to increase the amount of omega-6 fatty acids in breast milk, but there is not enough research about its safety and effectiveness. There had been one case of an infant born with transient petechiae to a mother taking evening primrose oil. [87-92]
- Ant-Platelet Drugs
- Protease Inhibitors including HIV/AIDS Drugs
Evening primrose oil is not a "drug", so the best doses have not been thoroughly established. Make sure to follow the specific product instructions and take as directed on the label, or consult a licensed healthcare practitioner before use.
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Encapsulated fish oil enriched in alpha-tocopherol alters plasma phospholipid and mononuclear cell fatty acid compositions but not mononuclear cell functions. Eur J Clin Invest. 2000 Mar;30(3):260-74. 6. Biagi PL, Bordoni A, Hrelia S, Celadon M, Ricci GP, Cannella V, Patrizi A, Specchia F, Masi M. The effect of gamma-linolenic acid on clinical status, red cell fatty acid composition and membrane microviscosity in infants with atopic dermatitis. Drugs Exp Clin Res. 1994;20(2):77-84. 7. Biagi PL, Bordoni A, Masi M, Ricci G, Fanelli C, Patrizi A, Ceccolini E. A long-term study on the use of evening primrose oil (Efamol) in atopic children. Drugs Exp Clin Res. 1988;14(4):285-90. 8. Bordoni A, Biagi PL, Masi M, Ricci G, Fanelli C, Patrizi A, Ceccolini E. Evening primrose oil (Efamol) in the treatment of children with atopic eczema. Drugs Exp Clin Res. 1988;14(4):291-7. 9. Belch JJ, Ansell D, Madhok R, O'Dowd A, Sturrock RD. 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Oral evening primrose oil and borage oil for eczema. Cochrane Database Syst Rev. 2013 Apr 30;4:CD004416. 88. DerMarderosian A, Beutler JA. The review of natural products: the most complete source of natural product information. 7th ed. St. Louis, MO, USA: Wolters Kluwer Health; 2012. 89. Fetrow CW, Avila JR. The complete guide to herbal medicines. Spring House, PA, USA: Springhouse Corporation; 2000. 90. Gruenwald J, Brendler T, Jaenicke C, editors. PDR for herbal medicines. 4th ed. Montvale, NJ, USA: Thomson Healthcare; 2007. 91. 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 Sep-Oct;36(5):657-61. 92. Tsai HH, Lin HW, Simon Pickard A, Tsai HY, Mahady GB. Evaluation of documented drug interactions and contraindications associated with herbs and dietary supplements: a systematic literature review. Int J Clin Pract. 2012 Nov;66(11):1056-78. 93. Bamford JT, Ray S, Musekiwa A, van Gool C, Humphreys R, Ernst E. Oral evening primrose oil and borage oil for eczema. Cochrane Database Syst Rev. 2013 Apr 30;4:CD004416. 94. DerMarderosian A, Beutler JA. The review of natural products: the most complete source of natural product information. 7th ed. St. Louis, MO, USA: Wolters Kluwer Health; 2012. 95. Fetrow CW, Avila JR. The complete guide to herbal medicines. Spring House, PA, USA: Springhouse Corporation; 2000. 96. Gruenwald J, Brendler T, Jaenicke C, editors. PDR for herbal medicines. 4th ed. Montvale, NJ, USA: Thomson Healthcare; 2007. 97. Tsai HH, Lin HW, Simon Pickard A, Tsai HY, Mahady GB. Evaluation of documented drug interactions and contraindications associated with herbs and dietary supplements: a systematic literature review. Int J Clin Pract. 2012 Nov;66(11):1056-78.
The "-" means there is no information.