Absorption of vaginal estrogen cream during sexual intercourse: a prospective, randomized, controlled trial.

OBJECTIVE: To determine if intercourse changed serum estradiol levels in women using vaginal E 2 cream or in their male partners. STUDY DESIGN: Prospective, randomized, placebocontrolled, crossover, blinded study of 10 postmenopausal women and their male sexual partners. Subjects were randomized to estradiol or placebo cream and intercourse, then crossed over after 7-14 days. Seven to 14 days later, the woman used vaginal estradiol cream and abstained from intercourse. Serum E 2 levels were obtained 10-12 hours after each exposure. RESULTS: Serum E 2 levels were higher in 8 of 10 men after intercourse with vaginal estradiol cream, and this resulted in a small but significant (p = 0.03) increase in the estradiol levels as compared to placebo. Paradoxically, intercourse resulted in markedly lower estradiol levels in women as compared to abstinence (p = 0.004). CONCLUSION: Men absorb vaginal estradiol during intercourse, whereas intercourse reduces estradiol absorption in women. Although serum estradiol levels were only mildly elevated in men, it is possible that long-term exposure could cause feminizing changes. In women, estradiol levels were markedly reduced by intercourse.