Arachidonic acid is an omega-6 essential fatty acid (EFA), which serves as a core regulator of protein synthesis (muscle growth) in humans. It supports the anabolic process by acting as precursor to hormone-like compounds called prostaglandins, specifically PGE2 and PGF2α. These prostaglandins are synthesized in the muscles when damaged from intense exercise, and facilitate tissue repair through several mechanisms including an increase in local IGF-1 (Insulin-like Growth Factor-1), testosterone, and insulin sensitivity, support of satellite cell activation, proliferation, and differentiation, and an increase in blood flow to the muscles (enhanced nutrient delivery).
While the average dietary intake of arachidonic acid is considered sufficient to meet the nutritional needs of most Americans, individuals that weight train or exercise regularly may benefit from additional supplementation. Studies show that regular exercise causes a significant lowering of arachidonic acid levels in muscle tissue. Because this EFA is so closely tied to protein synthesis, such depletion can impair how the muscles respond to training. By replenishing muscle arachidonic acid stores, supplementation can be a highly effective way of supporting new muscle growth and other positive adaptations to exercise.
Take a look into X-Factor the original arachidonic acid supplement created by the original patent holder, Molecular Nutrition.