LONDON, ENGLAND — A hormone-laced patch aimed at reviving the sex drive of women who have undergone hysterectomy may not be effective and could be unsafe, a British medical newsletter reported March 3rd.Intrinsa, a testosterone-delivery mechanism marketed in Europe by Procter and Gamble, is designed to deliver low doses of the naturally occurring hormone through a woman’s skin. Theoretically, wearing the patch will boost the sex drive of women who have entered “surgical menopause” after the removal of their ovaries.

Although approved for use in many European countries, the product was rejected by the U.S. Food and Drug Administration.

According to an article in Drug and Therapeutics Bulletin, clinical trials that led to the product’s approval in Europe were flawed. In addition, the bulletin noted, several of the trials unearthed what the publication termed “troubling side effects.” Primarily, the flaws consisted of test-subject selection criteria, although the bulletin noted that some subjects’ reporting of increased sexual desire after receiving a placebo may have been under-weighed in the analysis of the results, as well.

The two largest trials included more than 500 women each, the bulletin reported. Overall, improvements reported by the clinical trials were small, according to the bulletin article.

Efficacy aside, the bulletin article questioned whether a product that reportedly produced side effects in 75-percent of participants should be considered safe. The most common side effect was a skin rash at the site of patch-application, although other common side effects occurring in as many as 10-percent of trial subjects included acne, both excessive hair growth and hair loss, breast pain, weight gain, insomnia, deeper vocal tones and migraines.

“The long-term safety of the treatment is unknown,” the study concluded, based on the trials’ duration of a maximum of 24 weeks. “Unwanted side effects are common and not always reversible. For all these reasons, we cannot recommend Intrinsa for use in women with sexual dysfunction.”