Evening primrose capsules contain oil extracted from seeds of the plant Oenothera biennis. Some people use this oil either as a remedy for various health disorders or as a dietary supplement that provides the omega-6 fatty acid, gamma-linolenic acid. No high-quality evidence supports claims for specific health benefits, according to InteliHealth, but evening primrose oil is safe and most people do not experience side effects. Consult a qualified health care practitioner before taking any herbal supplements.
Skin Disorder Treatment
More than 30 studies report the effectiveness of oral evening primrose oil supplements for relieving symptoms of eczema and dermatitis according to Adventist Healthcare. Evening primrose oil also may be effective for treating skin rashes and hives. InteliHealth notes the oil is widely used in Europe for treating psoriasis and eczema with the suggested adult dose 4 g to 8 g daily divided into two doses. InteliHealth recommends consulting a health care professional before giving evening primrose capsules to children, but notes that studies with children have safely used 3 g daily divided into two doses.
Omega-6 fatty acids are essential fatty acids, meaning the body cannot produce them, and, therefore, you must obtain them by diet or supplements. The fatty acid contained in evening primrose, gamma-linolenic acid, is very hard to obtain through diet, according to physician Andrew Weil, who specializes in holistic medicine.
While some omega-6 fatty acids promote inflammation, gamma-linolenic acid actually reduces inflammation and does not have the side effects associated with anti-inflammatory drugs. Some research indicates gamma-linolenic acid may be beneficial for rheumatoid arthritis patients according to Arthritis Today.
Benefits for Diabetes Patients
Evening primrose oil has been shown to reduce blood sugar in diabetic humans and animals, according to InteliHealth, but long-term effects on blood sugar levels have not been determined. Gamma-linolenic acid may relieve nerve pain and other symptoms associated with diabetes, a condition known as diabetic neuropathy. A study published in the January 1993 issue of "Diabetes Care" found that supplementing with gamma-linolenic acid improved parameters of mild diabetic neuropathy, including hot and cold thresholds, sensation, tendon reflexes and muscle strength.
Considerations for Women
Many women in Europe and Australia take evening primrose oil for relieving unpleasant symptoms of menopause and premenstrual syndrome, including breast pain related to the menstrual cycle. However, InteliHealth notes that research does not support the use of evening primrose oil for menopausal symptoms. Research results are mixed on using evening primrose oil for premenstrual syndrome according to the National Center for Complementary and Alternative Medicine.