New Drug for Lost Libido

Dec. 1, 2006 — -- What is desire?

What triggers it?

And how can we make it last?

Some people think oysters, chocolate and ginseng -- among other mythical things --are aphrodisiacs.

They are rich in nutrients and give energy, but no one has proven they give you passion.

Even the "little blue pill" Viagra just works on, shall we say, the plumbing -- it keeps the blood flowing in the right direction.

Now there's a drug in the pipeline that its makers say really will restore lost libido.

It's being tested and developed, in part, in a laboratory at Concordia University in Montreal by neuroscientist Jim Pfaus.

Full-time college professor, part-time punk rocker, Pfaus is using rats to test whether the new substance, bremelanotide (pronounced "BREE-ma-LAN-o-tide") -- or PT 141 -- triggers desire.

Rats stand in for humans, because, like people, they're social and they have a similar hypothalamus, the part of the brain that controls desire.

In his lab, Pfaus says he's finding that bremelanotide seems to put rats in the mood.

Given the peptide, female rats, he says, initiate sex four times more often than those who do not receive it.

And bremelanotide's makers are betting it will work the same way on both men and women.

"It brings back your libido," Pfaus said. "It doesn't make it something that it wasn't. It brings it back to where it probably was when you were having good sex."

Bremelanotide didn't start out as a drug for sexual dysfunction.

In fact, it was being developed as a tanning enhancer, until researchers noticed interesting side effects in the men involved in clinical trials.

"All treatments for sexual dysfunction, especially erectile dysfunction, have colorful stories about how they started," said Carl Spana, CEO of Palatin Technologies, which holds the patent on bremelanotide. "In this particular one, young college men were given this drug in a Phase 1 study and got spontaneous erections.