Testosterone decrease in men with age has become well established. As such, several modes of testosterone replacement therapy have become available, primarily for supplementation to alleviate the effects of age associated hypogonadism, as manifested by frailty, sarcopenia, poor muscle quality, decreased libido and erectile functions. Recent investigations have found significant association between hypogonadism and cardiovascular disease, type 2 diabetes, obesity and dyslipidemia. The association is more clearly presented in patients receiving androgen deprivation therapy for prostate cancer. Furthermore, testosterone supplementation restores arterial vasoreactivity, reduces proinflammatory cytokines, total cholesterol, and triglyceride levels, and improves endothelial function and insulin sensitivity. Future long term trials should be performed to identify persistent benefits and safety of this treatment.