Avipaxin contains Huperzine A, which is a potent inhibitor of acetylcholinesterase, the enzyme that metabolizes acetylcholine. Blocking acetylcholinesterase increases circulating levels of acetylcholine. Avipaxin also contains ?-Glyceryl Phosphoryl Choline (?-GPC) and Acetyl-L-Carnitine. These ingredients supply choline and acetyl groups, respectively, for acetylcholine synthesis.