Time course of effects of testosterone administration on sexual arousal inwomen

Background: The assumption that testosterone is involved in human female se xual functioning is mainly based on results of studies of women with hypogo nadotropic hypogonadism This study sought to determine the effect of testos terone administration on physiological and subjective sexual arousal in sex ually functional women. Methods: In a double-masked, randomly assigned, placebo-controlled crossove r design, we examined whether administration of a single dose of testostero ne to sexually functional women increases vaginal and subjective sexual aro usal when they are exposed to erotic visual stimuli. To search for a time l ag in the effect of testosterone therapy, we exposed 8 healthy women to 6 e rotic film excerpts depicting intercourse. The first and second excerpts we re shown immediately before and 15 minutes after, respectively, intake of p lacebo or testosterone; the last 4 excerpts were then shown at 11/2-hour in tervals. Results: Sublingual intake of testosterone caused a sharp increase in plasm a testosterone levels within 15 minutes; these levels declined to baseline values within 90 minutes. Three to 41/2 hours after reaching peak testoster one level, we found a statistically significantly increase in genital respo nsiveness (P =.04). Furthermore, on the day of testosterone treatment, ther e also was a strong and statistically significant association between the i ncrease in genital arousal and subjective reports of "genital sensations" ( P =.02) and "sexual lust" (P =.01) after 41/2 hours. Conclusions: There is a time lag in the effect of sublingually administered testosterone on genital arousal in women. In addition, a consecutive incre ase in vaginal arousal might cause higher genital sensations and sexual lus t.