Evening primrose oil is the oil from the seed of the evening primrose plant. Evening primrose oil is used for skin disorders such as eczema, psoriasis, and acne. It is used to treat chronic fatigue syndrome, asthma, nerve damage related to diabetes, and an itching disorder called neurodermatitis. Women also use evening primrose oil for premenstrual syndrome (PMS), breast pain, endometriosis, and symptoms of menopause.