Testosterone supplementation did not show consistent benefit for cardiovascular risk , sexual function , mood and behavior , or cognition .
Studies that examined clinical cardiovascular endpoints have not favored testosterone therapy over placebo .
Testosterone is ineffective in treating erectile dysfunction and controlled trials did not show a consistent effect on libido .
Testosterone supplementation consistently increased muscle strength but did not have beneficial effects on physical function .
Most studies on mood-related endpoints found no beneficial effect of testosterone treatment on personality , psychological well-being , or mood .
Testosterone products are recommended by some prescribers in response to a diagnosis or presumption of " low testosterone " ( low-T ) for cardiovascular health , sexual function , muscle weakness or wasting , mood and behavior , and cognition .
Testosterone Gel Replacement Improves Sexual Function in Depressed Men Taking Serotonergic Antidepressants: A Randomized, Placebo-Controlled Clinical Trial
Testosterone replacement is the most effective treatment for  sexual dysfunction in hypogonadal men . Comorbid depression and antidepressant side effects may reduce its influence . The authors conducted a 6-week , double-blind , placebo-controlled clinical trial of testosterone gel versus placebo gel in men with major depressive disorder who were currently taking a serotonergic antidepressant and exhibited low or low-normal testosterone level . A total of 100 men were enrolled at 2 study sites ( Boston , Massachusetts , USA , and Tel Aviv , Israel ) . The effects of testosterone augmentation on sexual functioning were determined using domain scores on the International Index of Erectile Function ( IIEF ) . Complete pre- and posttrial IIEF data were available for 63 subjects . Men r and omized to testosterone ( n = 31 ) and placebo ( n = 32 ) were similar in age , baseline testosterone levels , and baseline IIEF scores . At study termination , men r and omized to placebo showed virtually no change from baseline in mean ( 95 % CI ) IIEF score ( −0.7 [ −6.5 , 5.2 ] ) , whereas those receiving testosterone exhibited a substantial increase ( 15.8 [ 8.5 , 23.1 ] ) . The estimated mean difference between groups was 16.8 [ 7.5 , 26.1 ] ; p = .001 by linear regression with adjustment for age and study site . There were also significant between-group differences in each of the 5 IIEF subscales , as well as on the single question involving ejaculatory ability ( p ≤ .03 in all cases ) . Effect sizes in these comparisons remained little changed , and generally remained statistically significant , when we further adjusted for change in depression scores on the Montgomery Asberg Depression Rating Scale . It is notable that the subgroup of men with the highest baseline testosterone levels showed virtually the same improvement as those with lower levels , suggesting that the observed improvement was unlikely to be due simply to correction of hypogonadism alone . In depressed men with low or low-normal testosterone levels who continued to take serotonergic antidepressants , treatment with exogenous testosterone was associated with a significant improvement in sexual function , particularly including ejaculatory ability
Testosterone supplementation did not show consistent benefit for cardiovascular risk , sexual function , mood and behavior , or cognition .
Studies that examined clinical cardiovascular endpoints have not favored testosterone therapy over placebo .
Testosterone is ineffective in treating erectile dysfunction and controlled trials did not show a consistent effect on libido .
Testosterone supplementation consistently increased muscle strength but did not have beneficial effects on physical function .
Most studies on mood-related endpoints found no beneficial effect of testosterone treatment on personality , psychological well-being , or mood .
Testosterone products are recommended by some prescribers in response to a diagnosis or presumption of " low testosterone " ( low-T ) for cardiovascular health , sexual function , muscle weakness or wasting , mood and behavior , and cognition .