100% Pure Evening Primrose Oil (EPO) is an all-natural vegetable oil. Used as an herbal treatment for a variety of ailments. EPO contains essential fatty acids that support body tissues, including skin. Each 1 ml of oil contains 80-100 mg of gamma-linolenic acid - an essential fatty acid that can nourish and protect healthy skin cells. 100% Pure EPO is derived from Evening Primrose seeds.