Alpha-GPC

Alpha-glycerylphosphorylcholine, or A-GPC, is a precursor to the neurotransmitter acetylcholine and might increase growth hormone levels, according to a study conducted by lead author Tim Ziegenfuss, Ph.D., and colleagues from the Center for Applied Health Science Research in Ohio. They studied the effects of A-GPC on growth hormone during resistance exercise. The report, published in the September 2008 issue of the "Journal of the International Society of Sports Nutrition," revealed that subjects taking 600 mg of A-GPC 1 hour before exercise experienced increases in growth hormone levels after exercise compared to those with a placebo.