Issues surrounding testosterone replacement therapy

Testosterone is derived from Leydig cells and exerts its effects on androgen receptors to influence growth, mood, voice, and several other bodily functions. As men age, their testosterone levels decline. Human immunodeficiency virus (HIV) infection has also been associated with lowered serum testosterone levels. Subtherapeutic levels of testosterone may lead to fatigue, loss of libido, and dysphoria. Exogenous replacement of testosterone can be accomplished by several modalities (oral, topical, injection), with each having distinct advantages and disadvantages. Even though testosterone replacement has become a popular medical intervention, recent reports have made the practice increasingly controversial. Several small retrospective investigations have recently associated testosterone replacement with an increased risk of cardiovascular complications. Replacement should be used sparingly until further conclusive data regarding the efficacy and safety of testosterone become available.