Arachidonic Acid (AA) is an Omega-6 polyunsaturated fatty acid with 4 double bonds. It’s a primary constituent of cell membranes, comprising 10-20% of the fatty acids in the membrane of cells in skeletal muscle. It’s a non-essential fatty acid meaning that we are able to synthesise it (unlike obligate carnivores like cats who cannot), being the final product of the Omega-6 fatty acid synthesis process starting with lipoic acid (the Omega 6 essential fatty acid).
AA increases Muscle Protein Synthesis (MPS). It does this by being converted to a prostaglandin (a lipid which has a hormone-like effect) called PGF2 Alpha during exercise. PGF2A is then able to activate MPS via the same mechanisms as leucine does. It’s been shown in one study to increase muscle mass and performance on a Wingate test at a dose of 1,500mg per day over 8 weeks, though at the time of writing this study had not been replicated.
AA does not appear to increase any markers of poor health upon supplementation and can be considered safe. The evidence for its efficacy is currently very thin, but this could be something you consider experimenting with if you are happy to divert spare money towards this avenue.