After Condom for Female now Viagra for Female

The first prescription treatment for women with a flagging libido could enter the market next year, and a second, related product might not be far behind.

Both deliver testosterone through the skin and are aimed at women who have had their ovaries removed, causing them to go into menopause. (Although testosterone is thought of as a male hormone, women's ovaries and adrenal glands produce small amounts.) The resulting low testosterone levels are associated with decreased sexual desire - thus the new products' nickname: "female Viagra."

Some observers are concerned that women who don't have low testosterone but want to boost their sex drive will get prescriptions. Already, some doctors have prescribed testosterone treatments approved only for men to postmenopausal women.

"It does need to be emphasized that this is not a benign drug in women," says endocrinologist Adrian Dobs of the Johns Hopkins School of Medicine. Over time, excessive testosterone can lead to facial hair growth, deepening of the voice and other signs of masculinization in women, Dobs says.

Testosterone can't fix all causes of low libido in women, such as vaginal dryness or relationship problems. "No one drug has been found to be the miracle treatment for men or women," Dobs says.

In a statement, Antares Pharma CEO Jack Stover said "credible estimates" put the U.S. market for testosterone products for women at $1 billion to $4 billion. The market for erectile dysfunction pills for men stands at $1.2 billion, says IMS Health. Expanded safety and effectiveness trials of its LibiGel are to begin next year, Antares says.

Procter & Gamble, maker of Intrinsa, a testosterone patch that could hit the market next spring, says about 10 million U.S. women have gone through surgical menopause. A third have low sexual desire, and half of that group are bothered by it, the company says.

That means roughly 1.65 million U.S. women might be candidates for Intrinsa or LibiGel, but their inventors have their eyes on a much bigger market: women who went through natural menopause.

P&G spokeswoman Elaine Plummer says her company will present data about Intrinsa in naturally menopausal women at a meeting next month. And Lawrence Christian, vice president of Antares, says he expects "off label" use of Intrinsa and LibiGel by women who still have their ovaries.