In a high-potency 1000mg capsule - Evening Primrose's special property is the oil in its seeds, which contains GLA, (Gamma-Linolenic Acid) an Essential Fatty Acid (EFA). Just Vitamins Evening Primrose Oil 1000mg provides 9% of the free fatty acid content as GLA - 80mg - together with 10mg of antioxidant Vitamin E. Top tip: If you are looking for higher levels of GLA then you should consider Just Vitamins Starflower Oil, as it contains 20% naturally occuring GLA.