Evening Primrose Oil is made from the seeds of a flowering plant native to North America. Evening Primrose Oil is a rich source of gamma-linolenic acid (GLA). GLA cannot be produced by the body, so we must consume enough GLA within our diet or aid GLA intake through supplementation. GLA is converted into Prostaglandin, a hormone-like substance which has been believed to provide numerous health benefits. Evening Primrose Oil contains added Vitamin E, which is a powerful antioxidant that provides protection of cells from oxidative stress.