Gamma-linolenic acid (GLA) is in the omega-6 family of essential fatty acids, but does not have the pro-inflammatory effects of other omega-6 fatty acids. EPO has been the most researched source of GLA. EPO has been used since the 1930s for eczema (a condition in which the skin becomes inflamed, itchy, or scaly because of allergies or other irritation). More recently it has been used for other conditions involving inflammation, such as rheumatoid arthritis. EPO is also used for conditions affecting women’s health, such as breast pain associated with the menstrual cycle, menopausal symptoms, and premenstrual syndrome. EPO is extracted from the seeds of the evening primrose, and put into gelcap form. EPO may have modest benefits for eczema, and it may be useful for rheumatoid arthritis and breast pain. Some clinical trials have shown a benefit of EPO for premenstrual syndrome. Usual dose is 1 or more sofgels per day, or as recommended by your physician.