Objective: Circulating testosterone in women declines during the late reproductive years such that otherwise healthy women in their 40s have approximately half the testosterone level as women in their 20s. Despite this, research showing the benefits of androgen replacement has been limited to the postmenopausal years. In view of the known premenopausal physiological decline in testosterone, we have evaluated the efficacy of transdermal testosterone therapy on mood, well-being, and sexual function in eugonadal, premenopausal women presenting with low libido.
Design: Premenopausal women with low libido participated in a randomized, placebo-controlled, crossover, efficacy study of testosterone cream (10 mg/day) with two double-blind, 12-week, treatment periods separated by a single-blind, 4-week, washout period.
Results: Thirty-four women completed the study per protocol, with 31 women (mean age 39.7 ± 4.2 years; serum testosterone 1.07 + 0.50 nmol/L) providing complete data. Testosterone therapy resulted in statistically significant improvements in the composite scores of the Psychological General Well-Being Index [+12.9 (95% CI, +4.6 to +21.2), P = 0.003] and the Sabbatsberg Sexual Self-Rating Scale [+15.7 (95% CI, +6.5 to +25.0), P = 0.001] compared with placebo. A mean decrease in the Beck Depression Inventory score approached significance [−2.8 (95% CI, −5.7 to +0.1), P = 0.06]. Mean total testosterone levels during treatment were at the high end of the normal range, and estradiol was unchanged. No adverse effects were reported.
Conclusions: Testosterone therapy improves well-being, mood, and sexual function in premenopausal women with low libido and low testosterone. As a substantial number of women experience diminished sexual interest and well-being during their late reproductive years, further research is warranted to evaluate the benefits and safety of longer-term intervention.
Total and free testosterone levels decline with age in premenopausal women such that women in their 40s have half the circulating levels of women in their 20s. 1 The levels remain stable across the menopausal transition 2 and then either remain stable or continue to decline with diminishing adrenal androgen production with increasing age. 4 In the decade preceding menopause, there is loss of the midcycle surge of free testosterone and androstenedione. 5 Thus, the proposed clinical manifestations of female androgen insufficiency–namely loss of libido, lowered mood, and fatigue 6 —may precede menopause but are not a consequence of natural menopause. 3 Published studies demonstrating beneficial effects of testosterone on sexual function 7–9,10–12 and mood and well-being 8,9,13,14 are limited to postmenopausal women, with no data regarding the effects of exogenous testosterone on sexual function and mood in premenopausal women. We undertook this study to investigate the efficacy of a physiological dose of testosterone, administered as a transdermal cream, on well-being, mood, and sexual function in otherwise healthy premenopausal women who considered themselves to have low libido. As there is no defined level of testosterone below which women can be said to be deficient, 6 we did not recruit women on the basis of their having “low” testosterone but rather excluded women for whom we believed testosterone therapy would be contraindicated. For this we arbitrarily excluded women with a testosterone level in the upper quartile of the normal range and above.
From the 1Jean Hailes Foundation Research Unit, Clayton, Victoria, Australia; and the 2Department of Epidemiology and Preventive Medicine, Monash University, Central and Eastern Clinical School, Prahran, Victoria, Australia.
Received December 10, 2002; revised and accepted January 23, 2003.
This study was supported by a Commonwealth Government Best Practice Grant to the Jean Hailes Foundation Research Unit, Clayton, Australia.
Address correspondence to: Susan R Davis, Jean Hailes Foundation Research Unit, 173 Carinish Road, Clayton, Victoria, Australia 3168. E-mail: firstname.lastname@example.org.