Gamma-linolenic acid. Computer model of a molecule of gamma-linolenic acid (GLA), an omega-6 essential fatty acid. Atoms are represented as spheres and are colour-coded; carbon (blue), hydrogen (gold) and oxygen (red). This is a polyunsaturated fat. It is found in plant oils, especially borage oil and evening primrose oil. In the body it can be produced from linoleic acid. GLA has many uses in herbal medicine, including relieving premenstrual tension, breast tenderness, eczema and controlling alcoholism.