A Vegetarian Fatty Acid That Imparts Important Health Benefits!NOW Evening Primrose Oil contains high levels of Gamma Linolenic Acid (GLA), the active ingredient in Evening Primrose Oil. Evening Primrose Oil is a nutritional oil containing 84% polyunsaturated fats. Linoleic acid and GLA are enhanced essential fatty acids. NOW Evening Primrose Oil is extracted through a natural expeller pressed process without the use of hexane or other chemical solvents. This Evening Primrose Oil is a more potent, concentrated form of Evening Primrose. Evening Primrose is a good vegetarian source of gamma linolenic acid (GLA), a fatty acid that imparts important health benefits.