Sexual Health: Revving Up Women's Sex Drive (cont.)
Shifren and colleagues recently tested testosterone patches on women who underwent menopause naturally and were taking estrogen therapy. The results of that study are expected in the fall. In addition, a trial of testosterone on menopausal women, not on estrogen therapy, is about to begin.
If all goes well, and the FDA gives its approval, the testosterone patch could be available in one to two years.
Some women use testosterone products designed for men, but these products have not been tested in large studies in women, and could have 10 times more hormones than women need, says Mary Lake Polan, MD, PhD, MPH, professor and chair of ob-gyn at Stanford University School of Medicine in California.
Too much testosterone in women could have masculinizing effects, such as hoarseness or deepening of the voice, unnatural hair growth or loss, acne or oily skin, decreased breast size, increase in the size of female genitals, and irregular menstrual cycles.
Additionally, other forms of testosterone such as creams and gels do not have conclusive evidence that they work to boost women's libido.
There is one FDA-approved androgen (male hormone) on the market for women. Estratest is a combination of oral estrogen and testosterone.
Although the product is only approved to treat estrogen-resistant hot flashes, it has been used "off-label" by doctors and patients. Off-label use means physicians prescribe drugs for a purpose other than what they are approved for.
Estratest has not been approved to improve sexual desire in menopausal women, but double-blind trials have shown it can do the job, says Shifren. "The nice thing is that it is a pharmacy-grade product designed for women. So there are a lot of data on safety and efficacy."
The drawback is that the drug is a fixed dose of a combination of estrogen and androgen. Women who may not need estrogen for hot flashes may not want to use the product.
"Estratest would be a very appropriate therapy for surgically menopausal women who, after surgery, notice hot flashes and a decrease in [sexual] desire," says Shifren.
Leiblum points out that Estratest and other drugs, while useful for some women, are not cure-alls for libido. "None of these [drugs] are probably going to be useful on their own," she says. "They all need to be seen as a multifaceted approach to both assessment and intervention."
Like all estrogens, the hormone may increase the risk of heart attack, stroke, breast cancer, endometrial cancer, and blood clots in the lungs or legs. Androgens can increase risk of liver cancer, and cause masculinizing effects in women.
There is some evidence that the antidepressant drug, Wellbutrin, may be able to boost women's libido.
In a 12-week preliminary study of 66 women most of who were not menopausal, 39% reported being satisfied with their levels of sexual desire. Harry Croft, MD, a psychiatrist and sex therapist based in San Antonio, reported the results of the study at the 2000 American Psychiatric Association meeting.
Experts say they are not aware of any large studies on Wellbutrin and sexual desire. But they aren't surprised that the drug may have some effect on women's libido.
"What happens sometimes is that people's sex drive goes up, because their depression is treated," says Koehler, noting that depression is often accompanied by lower sex drive. "So it may not be the Wellbutrin itself [that works]; it might be the feeling of being less depressed that is causing the increased sex drive."
None of the women in Croft's study was depressed when the trial began, but all had trouble becoming aroused or having orgasms.
Sometimes, a change in antidepressant drugs may help boost libido. SSRI-type medications such as Prozac and Zoloft are known to interfere with sexual desire. If a person switches from SSRI-type antidepressants to Wellbutrin, there may be an increase in sexual desire, because the others may be diminishing it, says Carol Rinkleib Ellison, PhD, a psychologist and author of Women's Sexualities.
On the other hand, Ellison says Wellbutrin could have the opposite effect of dampening desire. "People are really individual in how they respond to these medications," she says.
With names like Lioness, Xzite, and Rekindle, dozens of nutritional supplements line drugstore shelves with promises to enhance women's libido. Some of them even have an eye-opening price tag to go with claims. The daily supplement Avlimil, for instance, costs $324-$360 for a one-year supply.
Do any of them work?
Whipple says she knows of only two dietary supplements for sexual dysfunction that have been studied in double-blind, placebo-controlled trials: ArginMax and Zestra. The ArginMax trial looked at the supplement's effect on sexual desire, while the Zestra study looked at its effect on sexual arousal (libido is intact, but the woman has trouble becoming or maintaining aroused).
ArginMax appeared to not only have a positive effect on women's libido, but also showed satisfaction with sex lives -- an important, but often ignored factor, says Whipple.
Polan was one of the researchers involved in the studies on ArginMax. She says the supplement is safe for women to try on their own, but she still recommends that they first check in with their physicians.
"You don't want to miss what a doctor may pick up," says Polan. "You want to make sure there is not some organic, or metabolic, or physical reason for [the lack of sexual desire]."
Plus, it is important to make sure that herbal ingredients don't negatively interact with any medications you may be taking, says Whipple. For example, ArginMax contains gingko, which can promote bleeding. It is not an ingredient that would mix well with blood thinners such as aspirin or Coumadin.
Leiblum further warns that the FDA doesn't regulate natural ingredients. "Women may be getting very high levels, or very low levels, or totally zero levels of these supposed herbs."
Instead of looking at herbal remedies for lost libido, she recommends taking self-inventory. "It's more important to try to figure out why you lost [your libido], instead of trying to find a quick fix."