Gamma-Linolenic Acid (GLA) Monograph

Introduction Gamma-linolenic acid (GLA) is an important conditionally essential fatty acid (EFA). GLA is an omega-6 polyunsaturated fatty acid (PUFA). The fatty acid molecule is comprised of 18 carbon atoms with three double bonds. It is also known as 18:3n-6; 6,9,12-octadecatrienoic acid; cis-6, cis-9, cis-12octadecatrienoic acid; and gamolenic acid. GLA is found naturally in the fatty acid fractions of some plant seed oils. Most notably, sources of GLA include evening primrose oil (EPO), borage oil, black currant oil, and hemp seed oil. GLA is present in EPO at concentrations of 7-14 percent of total fatty acids; in borage seed oil at 20-27 percent; and in black currant seed oil at 15-20 percent. GLA is also found in some fungal sources, and a minimal amount is produced in the body as a downstream metabolite of the delta-6-desaturase induced conversion from the EFA linoleic acid. Under certain conditions, such as decreased enzymatic activity of delta-6-desaturase, GLA may become conditionally essential. GLA is also present naturally in the form of triglycerides.