Genital and subjective measurement of the time course effects of an acute dose of testosterone vs. placebo in postmenopausal women

Introduction. Recent research on the impact of testosterone (T) on female sexual function has yielded inconsistent results, and few studies have used physiological measures of genital arousal. Aim. This study examined the effects of an acute dose of methyltestosterone (MT) on physiological (genital) and subjective sexual response in postmenopausal women. Main Outcome Measures. Vaginal pulse amplitude (VPA) and self-reported sexual response. Methods. Randomized, double-blind, crossover, placebo-controlled trial of 5 mg MT, consisting of two separate 8-hour visits. Participants were 10 postmenopausal women without sexual dysfunction. Participants viewed both neutral and erotic video segments during five post-dose trials while their genital and subjective responses were monitored. Results. The Wilcoxon signed rank test indicated a significant difference in VPA between the T (M = 0.018, SD = 0.018) and placebo (M = 0.016, SD = 0.017) conditions at 4.5 hours post-dose (P = 0.03). Higher difference scores were noted for 80% of subjects during the T condition at 4.5 hours, in contrast with only 50% of subjects responding to T at the other four time points. No differences were found on VPA relative change scores or subjective sexual arousal scores. When summed across all five time points, genital and subjective measures were correlated regardless of medication condition (0.62 and 0.60 for self-reported physical and mental sexual arousal scores, respectively). Conclusions. These findings in postmenopausal women combined with those of two previous investigations in premenopausal women demonstrate a probable acute-dose time delay for genital sexual effects of exogenous T with no change in self-reported sexual arousal. Further investigation is needed to determine whether acute dosing of T has a consistent and predictable impact on genital arousal that has promise for the treatment of any subgroup of women with sexual disorders.