ED Drugs May Boost Orgasm Hormone

Aug. 27, 2007 -- New research shows that erectile dysfunction drugs such as Viagra, Levitra, and Cialis may increase production of oxytocin, a reproductive hormone released during orgasm.

That news comes from scientists at the University of Wisconsin at Madison.

They tested sildenafil (Viagra's active ingredient), vardenafil (Levitra's active ingredient), and a related chemical called T-1032 in lab tests on rats.

The researchers exposed part of the rats' pituitary gland to those chemicals (which are called PDE5 inhibitors) and to mild electrical stimulation. Under those conditions, the rats' pituitary glands produced more oxytocin.

Does that happen in people, too? This study doesn't answer that question.

But that topic deserves further study, since oxytocin is important in various reproductive functions, write researcher Meyer Jackson, PhD, and colleagues.

Their study shows no signs of increased oxytocin production without stimulation.

"Erectile dysfunction drugs do not induce erections spontaneously; they enhance the response to sexual stimulation," Jackson states in a news release.

"The same thing is happening in the [rats'] posterior pituitary -- Viagra will not induce the release of oxytocin on its own, but it will enhance the amount of release you get in response to electrical stimulation," states Jackson.

Their findings appear in the Aug. 9 advance online edition of the Journal of Physiology.