Testosterone therapy is an effective treatment for low libido in postmenopausal women, suggest results of an international study of more than 800 women.

Previous research has shown that testosterone therapy is useful for restoring libido in women when used in conjunction with estrogen replacement therapy. However, this study is the first to show that testosterone by itself can enhance sexual wellbeing in postmenopausal women.

For the year-long study researchers randomly assigned 814 women with hypoactive sexual desire disorder to receive a skin patch delivering 150 or 300 µg of testosterone per day or placebo. The primary endpoint of the study was the change from the start of the study to week 24 in the 4-week frequency of satisfying sexual episodes.

Results showed that women receiving 300 µg of testosterone per day experienced a significant increase in satisfying sexual episodes compared to women receiving the placebo (2.1 episodes versus 0.7). Women receiving 150 µg testosterone per day did experience an increase in satisfying sexual episodes (1.2 episodes), however the increase was not statistically significant. In comparison with the placebo group, women receiving both doses of testosterone experienced significant increases in desire.

The researchers concluded: “In postmenopausal women not receiving estrogen therapy, treatment with a patch delivering 300 µg of testosterone per day resulted in a modest but meaningful improvement in sexual function.”

Davis SR, Moreau M, Kroll R, et al. Testosterone for low libido in postmenopausal women not taking estrogen. NEJM 2008:359:2005-2017.