In symptomatic men 65 years of age or older, raising testosterone concentrations for 1 year from moderately low to the mid-normal range for men 19 to 40 years of age had a moderate benefit with respect to sexual function and some benefit with respect to mood and depressive symptoms but no benefit with respect to vitality or walking distance. A study funded by the National Institutes of Health assigned 790 men 65 years of age or older with a serum testosterone concentration of less than 275 ng per deciliter and symptoms suggesting hypoandrogenism to receive either testosterone gel or placebo gel for 1 year. Each man participated in one or more of three trials–the Sexual Function Trial, the Physical Function Trial, and the Vitality Trial. The primary outcome of each of the individual trials was also evaluated in all participants. Testosterone treatment increased serum testosterone levels to the mid-normal range for men 19 to 40 years of age. The increase in testosterone levels was associated with significantly increased sexual activity, as assessed by the Psychosexual Daily Questionnaire (P<0.001), as well as significantly increased sexual desire and erectile function. The percentage of men who had an increase of at least 50 m in the 6-minute walking distance did not differ significantly between the two study groups in the Physical Function Trial but did differ significantly when men in all three trials were included (20.5% of men who received testosterone vs. 12.6% of men who received placebo, P=0.003). Testosterone had no significant benefit with respect to vitality, as assessed by the Functional Assessment of Chronic Illness Therapy-Fatigue scale, but men who received testosterone reported slightly better mood and lower severity of depressive symptoms than those who received placebo. The rates of adverse events were similar in the two groups. The number of participants, however, was too few to draw conclusions about the risks of testosterone treatment. See Peter J. Snyder et al. (2016).
Many claims made for prasterone are in regard to slowing or reversing the aging process and improving quality of life in otherwise healthy middle-age or elderly individuals. These claims include: maintenance of body composition/strength; enhancement of physical or psychological well-being; memory or cognition enhancement; and improvement of age-related declines in insulin sensitivity and immunity. Many studies have generated conflicting results, usually due to the small sample sizes, concurrent therapies, and/or poor trial design. No study has demonstrated prolongation of life in elderly patients treated with prasterone.