Evening Primrose Oil comes from the seeds of the Oenothera biennis plant. It is a very rich source of natural γ-linolenic acid and is an omega-6 fatty acid which is also found in Borage Oil and Black Currant Seed. Although the human body can synthesize γ-linolenic acid through other dietary lipids, it is believed that γ-linolenic acid in its pre-synthesized form can be used more efficiently in all body functions.