Evening primrose oil is a rich source of gamma linolenic acid (GLA), a precursor to a hormone-like substance called PGE1. PGE1 may play a role in reducing PMs, promoting skin health and calming skin inflammation, as well as alleviating joint pain. It also has hormone balancing effects and is a source of omega 6 fatty acid. Additionally, vitamin E in the oil protects cells against oxidative stress. This product is available in a 90-capsule size.