The anabolic androgenic steroid is a family of lipophilic hormones derived from cholesterol, which includes the natural male hormone testosterone and its synthetic derivatives, such as nandrolone and androsterone ( Janjic et al. 2012; Basile et al. Testosterone is the main molecule that possesses both anabolic and androgenic properties, which semantically refers to the ability to stimulate the synthesis of complex biological molecules and the growth of male characteristics, respectively (Quan et al. 2011).Testosterone supplement has been used in medicine since its discovery as an effective treatment of hypogonadism or severe muscle catabolism. However, due to poor efficacy in the form of oral medications and parenteral injection, testosterone is being modified chemically into different types of anabolic androgenic steroids to maximize anabolic effects and minimize unwanted androgenic effects (Schanzer 1996 and Fontana et al. 2013). .Effect of testosterone on fat mass Testosterone regulates many physiological processes such as muscle protein metabolism, sexual and cognitive functions, secondary sexual characteristics and bone metabolism (Bhasin et al. 2001). In general, most anabolic androgenic steroids are modified to share the same function as testosterone, despite the efficacy and different metabolic pathways due to different stereochemical structures and additional chemical groups (Schanzer 1996). Testosterone has been reported to have a correlation with whole body and regional fat mass. One study showed that hypogonadal men, that is, males who have a lower physiological level of testosterone, have higher fat mass than men with a normal physiological level of testosterone. The study also shows… half of the article… androgenic steroid-related dopamine dysregulation (Ricci et al. 2010). Conclusion Anabolic androgenic steroids have extraordinary effects on fat loss and building muscle and other male characteristics. . Its uses in medicine benefit many patients suffering from diseases related to hormonal disorders and muscle disorders. However, considering the adverse effects and potential serious harm to the human body, the government should limit legislation on the regulation of anabolic androgenic steroids, ban unauthorized sales of steroid-containing products, and educate the public about serious side effects to reduce the possibility of abuse . More research is needed on the molecular biology, potential applications, and adverse effects of testosterone; therefore, the power of anabolic androgenic steroids can be used to improve our well-being.