There's a patch to help people stop smoking on the market and one to prevent pregnancy, as well. But the patch to enhance a woman's sexual desire (Intrinsa) may not be approved anytime soon. An expert panel has recommended that the Food and Drug Administration wait for additional data proving the safety of this women's version of Viagra.

It's by clinical studies that experimental products such as the Intrinsa passion patch must prove their safety and effectiveness to earn the FDA's approval for marketing.

Female Aphrodisiac: Not Far Behind
One product is worth keeping a hopeful eye on, though it is still in preliminary trials: PT-141, a synthetic form of a brain hormone, which is right behind Intrinsa in the race to become the first bona fide female aphrodisiac. The drug, which is being studied, too, for use in men to promote erections, has completed its first-phase trials in women. So far, it has aroused female rats, causing them to chase after males to feed their spiked sexual appetite. Other products to promote sexual health are in various stages of clinical trials.

Other products to promote sexual health are in various stages of clinical trials. Showing promise against impotence:

• Uprima. Two forms — a tablet dissolved under the tongue and a nasal spray — both stimulate the brain chemical dopamine to intensify sexual sensations. Clinical trials continue in the United States for this drug, already available in Europe, which has been associated with fainting in a small number of people who have taken it.
• Topiglan. Topiglan, a version of the drug alprostadil that is already used in injection and suppository forms, is applied to the penis as a gel or cream and could become the first topical drug to treat erectile dysfunction.
• Alibra. This version of alprostadil under review by the FDA contains a painkiller and is longer lasting than its approved predecessor.

And under study for women: Tibolone, already approved in Europe and Australia, may increase vaginal lubrication, arousal level and sexual desire. On the disappointing side, the makers of the male blockbuster drug Viagra recently gave up seeking approval of the drug for female sexual dysfunction because results weren't strong enough to prove it works in women.

Low-Dose Testosterone in Improving Libido in Postmenopausal Female Cancer Survivors

The Effect of 5-Alpha Reductase on Testosterone in Men

Ginkgo Biloba: Antidepressant-Induced Sexual Dysfunction

Nerve-Sparing Radical Prostatectomy With or Without Nerve Grafting Followed by Standard Therapy for Erectile Dysfunction in Treating Patients With Localized Prostate Cancer

Sildenafil in Treating Erectile Dysfunction in Patients With Prostate Cancer

If you are interested in joining these or future studies, visit the National Institutes of Health's ClinicalTrials.gov Web site, and do a search for the type of study that might be right for you.