Universal Nutrition Animal Hormone Booster Stak®Animal Stak is a comprehensive, natural, anabolic, performance supplement designed to help men build lean muscle. The supplement is packed with five unique complexes to boost natural testosterone levels and support growth hormone (GH) elevation giving you increased muscle mass, strength, energy, and vitality. Naturally enhance output of testosterone while lowering estrogen levels Increased muscle mass, endurance, strength, energy, and vitality Better