Effect of transdermal testosterone on postmenopausal sexual desire: placebo-controlled randomized clinical trial

OBJECTIVE: The transdermal administration of testosterone is a promising alternative to improve sexual health in postmenopausal women with decreased sexual desire, although its use remains off-label in Brazil and several other countries. This study aimed to evaluate the effect of compounded transdermal testosterone on serum testosterone concentrations as the primary outcome, and on Free Androgen Index, sex hormone binding-globulin (SHBG), and Female Sexual Function Index (FSFI) scores as secondary outcomes, in postmenopausal women under hormone replacement therapy. METHODS: This placebo-controlled randomized clinical trial evaluated serum testosterone concentrations and sexual satisfaction indices in 47 postmenopausal women undergoing isolated or combined hormone therapy who reported decreased sexual desire, comparing a group that received compounded transdermal testosterone to a placebo group. Participants were selected consecutively from April 2023 to April 2024; they were randomized and underwent laboratory tests and completed the FSFI questionnaire before and after treatment. RESULTS: The results showed that the testosterone group had a significant increase in total testosterone levels (p = 0.001) and the Free Androgen Index (p = 0.004), along with improvements in several FSFI domains, such as desire and sexual satisfaction. In contrast, the placebo group did not show an increase in testosterone levels, although it did show improvement in the pain domain. Both groups did not alter SHBG levels (p = 0.876 in testosterone group). CONCLUSION: Although transdermal testosterone therapy was effective in increasing hormone levels and improving sexual function, variability in hormone concentrations posed challenges in evaluating compounded medications.