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 .
A pilot study on the effects of testosterone in hypogonadal aging male patients with Alzheimer's disease
The male aging process brings about declines in hormonal function including a gradual decline in bioavailable testosterone levels . Animal studies suggest that testosterone modulates cognitive function through enhancing acetylcholine release and up-modulation of nicotinic receptors . Tau protein deposition is also affected by and rogen supplementation in animals . We hypothesize that testosterone replacement in elderly hypogonadal males may improve cognition , in particular the visual-spatial domain . Thirty-six male patients with a new diagnosis of Alzheimer 's disease had their total and bioavailable testosterone levels measured . None of the patients had been on acetylcholinesterase inhibitors .  Ten of the 36 patients ( 28 % ) were deemed biochemically hypogonadal ( total testosterone < 240 ng/dl or 7 nmol/l ) . Five of the hypogonadal patients were r and omized to testosterone and five to placebo . Initial Alzheimer 's Disease Assessment Scale cognitive subscale ( ADAScog ) and Mini Mental Status Examination ( MMSE ) ranged from 31 to 19 and from 17 to 22 , respectively . The  clock drawing test ( CDT ) and the pentagon-tracing portion of the MMSE were used as measures of visual-spatial abilities . Normal prostate-specific antigen ( PSA ) levels were essential before treatment with intramuscular testosterone , 200 mg every 2 weeks . Measurement of testosterone , complete blood count , lipids , PSA and neuropsychological cognitive tests were repeated at 3 , 6 , 9 and 12 months of treatment . In the testosterone-treated group , levels of total testosterone increased from a mean of 126.4 ng/dl to 341 ng/dl or 3.6 nmol/l to 9.7 nmol/l ( p = 0.11 ) . Bioavailable testosterone also increased from a mean of 48.7 ng/dl to 142 ng/dl or 1.39 nmol/l to 4.05 nmol/l ( p = 0.10 ) . PSA levels were also elevated from a mean of 0.98 to 1.37 ng/ml ( p = 0.07 ) . ADAScog improved from a mean of 25 to 16.3 ( p = 0.02 ) ; MMSE improved from a mean of 19.4 to 23.2 ( p = 0.02 ) , CDT also improved from 2.2 to 3.2 ( p = 0.07 ) . One patient stopped treatment because of hypersexual behavior . The placebo-treated group deteriorated gradually . This small pilot study performed in aging male patients suggests that testosterone could indeed improve cognition , including visual-spatial skills in mild to moderate Alzheimer 's disease
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 .