- One of the most popular evening primrose supplements - One of the few natural sources of the omega 6 fatty acid, GLA - Includes vitamin E at 83% NRV - Each capsule provides 1000mg of high quality oil specially selected for its purity and consistent GLA level This is Lamberts most popular Evening primrose product as it is the size and potency that is best well known, and for many years the strongest GLA supplement we supplied. Evening primrose oil is still a popular supplement as the oil is one of the few natural sources of an omega 6 fatty acid called Gamma-Linolenic Acid (GLA). The body uses GLA to make a specific prostaglandin which takes part in regulating the nervous, cardiovascular and reproductive systems, as well as maintaining healthy skin condition and other biological functions. Our bodies can actually make GLA from Linoleic Acid (the omega 6 fatty acid present in vegetable oils) but this conversion is sometimes slow or partially blocked. Hence, a dietary source of GLA can be very useful and numerous clinical trials have established that GLA supplements can be effective in certain situations.