Studies have failed to prove that Viagra works for women. Pfizer issued a statement tonight saying that, despite research into whether the pill can also work as a sort of "Spanish Fly" for women, the effort sort of, well, petered out:

"While we are disappointed that the (research) program was not more successful, this is the nature of drug development," said Karen Katen, president of Pfizer Global Pharmaceuticals, executive vice president, Pfizer Inc.

Pfizer plans to keep plugging away until it finds a treatment, she said.