Evening Primrose Oil is one of the few natural sources of a polyunsaturated fat called Gamma-Linolenic Acid (GLA). GLA is a precursor to a particularly important prostaglandin called PGE1, which is involved in regulating the nervous system, cardiovascular system, reproductive system, skin health, and other biological functions.

While the body can convert GLA from Linoleic Acid (the Omega-6 fatty acid found in plant oils), this conversion is sometimes slowed down or completely inhibited. For this reason, a dietary source of GLA can be very beneficial for the body to bypass the conversion process, and numerous clinical trials have shown that GLA supplements can be effective in specific cases.