Effect of Deodorant and Antiperspirant Use and Presence or Absence of Axillary Hair on Absorption of Testosterone 2% Solution Applied to Men's Axillae

IntroductionTestosterone 2% solution is applied to axillae and is indicated for testosterone replacement therapy in males deficient in endogenous testosterone.AimThis open‐label crossover study evaluated the effect of deodorant/antiperspirant use and presence or absence of axillary hair on absorption of testosterone solution.MethodsHealthy males (N = 30; ≥50 years of age with baseline testosterone <400 ng/dL) were randomized to one of four treatment sequences involving six treatments. Each treatment consisted of one 1.5‐mL dose of testosterone 2% solution (30 mg of testosterone) applied to each axilla. Axillae were unshaved or shaved, and were untreated or pretreated with deodorant/antiperspirant.Main Outcome MeasuresBlood samples were taken over 72 hours after each dose for measuring serum testosterone concentrations.ResultsProfiles of mean testosterone concentrations were similar across treatments. For all treatments, area under the concentration‐time curve through 24 hours (AUC[0–24]) and 72 hours (AUC[0–72]), and maximum total testosterone concentration (Cmax) were similar except for 15% lower Cmax when treatment was applied after deodorant/antiperspirant to shaved vs. unshaved axillae (least squares mean, 531 ng/dL vs. 626 ng/dL, respectively; P = 0.011). This difference is not considered clinically significant. The 95% confidence intervals for AUC(0–24), AUC(0–72), and Cmax fell within the traditional bioequivalence limits of 0.8 to 1.25. Incidence of treatment‐emergent adverse events (TEAEs) was low (<15%) in each treatment arm, and most TEAEs were mild.ConclusionsAbsorption of testosterone 2% solution was unaffected by use of deodorant/antiperspirant or by the presence or absence of axillary hair. Testosterone solution was generally well tolerated. Small DS, Ni X, Polzer P, Vart R, Satonin DK, and Mitchell MI. Effect of deodorant and antiperspirant use and presence or absence of axillary hair on absorption of testosterone 2% solution applied to men's axillae. J Sex Med 2014;11:2809–2817.