Nature39s own evening primrose oil is high in fatty acids including the essential omega 6 linoleic acid 70 and the non essential omega 6 gamma linolenic acid 9 gamma linolenic acid gla is essential for the production of certain hormones called prostaglandins which regulate many body functions such as blood pressure and the reproductive cycle although the body can produce gla directly from linoleic acid sometimes the conversion is not very efficient so a supplement might b