Don't know much about this.... from Wiki
Arachidonic acid (AA, sometimes ARA) is a polyunsaturated omega-6 fatty acid 20:4(ω-6). It is structurally related to the saturated arachidic acid found in Cupuaçu butter. Arachidonic acid is marketed as an anabolic bodybuilding supplement in a variety of products. Supplementation of arachidonic acid (1,500 mg/day for 8 weeks) has been shown to increase lean body mass, strength, and anaerobic power in experienced resistance-trained men. This was demonstrated in a placebo-controlled study at the University of Tampa. Thirty men (aged 20.4 ± 2.1 years) took arachidonic acid or a placebo for 8 weeks, and participated in a controlled resistance-training program. After 8 weeks, Lean Body Mass (LBM) had increased significantly, and to a greater extent, in the ARA group (1.62 kg) vs. placebo (0.09 kg) (p<0.05). The change in muscle thickness was also greater in the ARA group (.47 cm) than placebo (.25 cm) (p<0.05). Wingate anaerobic power increased to a greater extent in ARA group as well (723.01 to 800.66 W) vs. placebo (738.75 to 766.51 W). Lastly, the change in total strength was significantly greater in the ARA group (109.92 lbs.) compared to placebo (75.78 lbs.). These results suggest that ARA supplementation can positively augment adaptations in strength and skeletal muscle hypertrophy in resistance-trained men.
I know Universals Animal Test has this in it, as well as Molecular Nutrition X-Factor.