June 26, 2003 -- It's looking more and more like the male hormone testosterone may do for women what Viagra did for men.
A newly released study offers some of the best medical evidence yet that the hormone really can help many postmenopausal women with sexual desire problems get in the mood.
Investigators found that boosting testosterone levels was associated with increased sexual desire in women who complained of menopause-related low libido and reduced sexual arousal. Women taking a low-dose estrogen-testosterone combination treatment reported a two-fold improvement in sexual interest, compared with women treated with estrogen alone.
There are currently no medications approved in the United States for the treatment of low libido in women, but many doctors already are prescribing androgens like testosterone or the chemically similar steroid hormone DHEA for this purpose.
"We have known that this works, but we haven't had the rigorous clinical studies to back that up," sexual dysfunction specialist Irwin Goldstein, MD, tells WebMD. "This study represents a major advance."
The Boston University School of Medicine urologist says he has used testosterone or a similar androgen in the treatment of more than 600 women with sexual desire problems over the past five years, with a success rate in the neighborhood of 70%.
"There is no question in my mind that this therapy will do for many women what Viagra has done for men," he says.
The study included 221 healthy, postmenopausal women who complained of having little or no sexual desire, even though they were already taking estrogen therapy for menopausal symptoms.
Half the women were treated for 16 weeks with the low-dose oral estrogen-testosterone combination drug Estratest HS, and the others took a similar dose of estrogen alone. Testosterone levels were measured at the beginning and end of treatment, and all women completed questionnaires designed to measure their sexual interest.
By week eight, the testosterone-treated patients had measurable improvements in testosterone levels that put them in the upper normal range, and they reported improved interest in sex. They also reported none of the common side effects of treatment with larger doses of testosterone, such as excessive hair growth and acne. The study is published in the June issue of the journal Fertility and Sterility.
But no Cure-all
Columbia University ob-gyn Rogerio A. Lobo, MD, who led the study team, says the results confirm that testosterone is an effective treatment for lack of sexual desire in postmenopausal women who do not respond to estrogen alone and whose libido problems are not caused by depression.
"Certainly testosterone is not the answer for all women with sexual desire problems. It is not a cure-all," he tells WebMD. "But the results were saw were definitely significant. The improvement in desire seemed to correlate with rising testosterone levels."
Although this study looked only at postmenopausal women, testosterone is also being used for sexual desire problems in younger women. New research from Australia confirms that testosterone levels drop in women well before they reach menopause.
While he is excited about the potential of testosterone therapy, Goldstein agrees that it is not a cure-all for all women who have no interest in sex.
"The cause of low desire isn't always medical, but it turns out that a large percentage of women with this problem have blood tests that are consistent with low levels of testosterone and other androgens," he says.