SERM and AI are Bodybuilders used to reduce and prevent estrogen-related adverse reactions in AAS cycle. SERM is a modulator of estrogen receptors, including tamoxifen and clomiphene. AI is an aromatase inhibitor, including exemestane and Arimidex. AI is divided into two types, one is an irreversible steroid inhibitor, such as exemestane, that forms a permanent binding to the aromatase complex. …