April 14 (HealthDay News) -- Testosterone spray slightly improved sexual satisfaction in premenopausal women, but a placebo had the same effect, a new study reports.

Researchers look at 261 women, aged 35 to 46, who were treated at six medical centers in Australia. The women, with self-reported low libido and low serum-free testosterone levels, were randomly assigned to receive one of three different doses of a testosterone spray or a placebo daily for 16 weeks.

At the end of that time, all the women reported increased frequency of sexually satisfying events. The difference between the testosterone spray and the placebo was statistically significant only for women who received the middle dose of testosterone.

The researchers found that 81 percent to 86 percent of women in the testosterone groups and 70 percent of the women in the placebo group reported adverse side effects. The most common was hair growth on the abdomen, where the testosterone was sprayed.

The study was published in the April 15 issue of the Annals of Internal Medicine.

In an accompanying editorial, Dr. Rosemary Bassone, of the University of British Columbia in Vancouver, wrote that women's testosterone levels and libidos may decline as they age, but that doesn't mean the lack of testosterone is linked with sexual dissatisfaction.

"We do not have a fully satisfactory rationale for testosterone therapy," and there is a "lack of long-term safety data," Bassone wrote.

Instead of prescribing testosterone for women with sexual dissatisfaction, doctors should examine health and relationship issues, sexual dysfunction in the partner, and treat problems using conventional methods such as cognitive behavioral therapy, sex therapy and psychotherapy, Bassone recommended.

SOURCE: Annals of Internal Medicine, news release, April 14, 2008