As of 2015, there is no recommended evening primrose oil dosage for help with menopause, states the National Center for Complementary and Integrative Health. Results from preliminary studies show a clear lack of evidence of its efficacy with menopausal and premenstrual syndrome symptoms.
Evening primrose oil is an herbal remedy with a high concentration of gamma-linolenic acid, states the American Cancer Society. GLA is an omega-6 fatty acid essential to many body processes while its anti-inflammatory effect helps in relieving symptoms of atopic dermatitis, eczema and breast pain. In addition, the body also converts GLA to prostaglandin E1, a hormone useful in contracting blood vessels.