Impotence drugs such as Viagra may do more than help men physically have sex - they may also boost levels of a hormone linked with feelings of love, U.S. researchers reported on Thursday.
Viagra, known generically as sildenafil, raised levels of the hormone oxytocin in rats, the team at the University of Wisconsin-Madison said in a report published in the Journal of Physiology.
This hormone is involved in nursing and childbirth but also in orgasm and feelings of sexual pleasure.
And it seems Viagra and related drugs act on the part of the brain that controls release of oxytocin, said Wisconsin physiology professor Meyer Jackson.
"This is one piece in a puzzle in which many pieces are still not available," Jackson said in a statement. "But it raises the possibility that erectile dysfunction drugs could be doing more than just affecting erectile dysfunction."
People use the impotence drugs for fun, instead of using them as prescribed for sexual dysfunction caused by low blood flow to the genitals.
The drugs can cause fatal side effects if used with certain other drugs, and some studies also suggest they may affect the eyes in some patients, so doctors stress they are not for casual use.
