Evening primrose oil contains gamma-linolenic acid (GLA), an essential fatty acid. Essential fatty acids are required by the body for growth and development, and must be obtained from the diet.

• Evening primrose oil 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.
• Evening primrose oil is used for conditions affecting women's health, such as breast pain associated with the menstrual cycle, menopausal symptoms, and premenstrual syndrome.