Contains Arimistane, also known as Androsta-3, 5-diene-7, 17-dione, is an aromatase inhibitor (AI). Many people will refer to this compound as an "anti-estrogen" supplement because it blocks and reduces estrogen. When reducing estrogen your testosterone levels will start to increase. This can be extremely beneficial because testosterone is responsible for muscle growth, strength, and recovery. This could be ideal for a bodybuilder wanting to build more muscle. Contains 30 Caps