This study aimed to evaluate what is new in the controversial use of testosterone, as an indication in pathologies such as hypogonadism or its use by athletes and bodybuilders in search of performance. Much is said about the subject and many myths were created without any scientific foundation, one of the objectives of the monograph is to show that when there is a precise clinical indication, testosterone is necessary and extremely beneficial to the patient. It was evaluated in current literature through books and articles, advances in physiology, regulation, treatment of late adult hypogonadism, incidence of use and the most common analogues used by athletes, the harms and benefits expected from the use of the hormone and especially what we have again on cardiovascular safety in testosterone use. After an extensive review, it is still not possible to affirm all the benefits and harms of using the hormone, many old studies are disputed in new studies and even presented results opposite to what was previously believed.