The Gynecologist

Viagra for Women?

You may have seen the headlines about a new medication hitting the market. Flibanserin, trade named Addyi, has been hailed as ‘female Viagra’, the ‘little blue pill’ for women, and a game-changer in the treatment of low libido (decreased sexual desire) in women. But many of these ‘news’ stories have more in common with paperback bodice-ripper novels and than they do with real, medical science. So let’s bust some myths and discuss what these pills, both Viagra and Addyi really are and what they can and can’t do.

Viagra (medical name: sildenafil) works for men with erectile dysfunction (ED) by increasing blood flow to the penis. This allows a man to get and keep an erection which is hard enough for sexual intercourse. Viagra works by inhibiting a specific enzyme, allowing for greater concentrations of a chemical called nitric oxide in penile tissue. Elevated levels of nitric oxide result in relaxation of the smooth muscle in the walls of blood vessles. So, by causing relaxation of these blood vessel walls, the vessels enlarge and can hold more blood, engorging and enlarging the erectile tissue of the penis.  It all sounds pretty sexy, doesn’t it?

That’s right. The sole medical purpose of Viagra is to allow men to get more satisfactory erection in response to stimulation of the penis. Viagra does not have any direct effect on libido or sex drive. That being said, getting a harder, longer lasting erection and a more satisfying sex life can have an indirect effect on libido (so can a good Ryan Gosling flick, if you ask me. But you didn’t.).

Addyi (medical name: flibanserin) on the other hand, does have a direct effect on libido. As we all know, libido is centered in the brain (and, according to conventional wisdom, women only have one brain whereas men sometimes have two. But we won’t go there).

Flibanserin is a serotonin agonist, meaning that it binds to (but does not activate or ‘turn on’) receptors for serotonin, a neurotransmitter (chemical signal) in the brain. It also increases circulating levels of 2 other neurotransmitters, norepinephrine and dopamine.

By altering responses to these chemical signals in the brain, it is said to directly affect sexual desire and libido. In actuality (ie, in clinical trials), the medication increased the number of satisfying sexual events per month by about one half to one over placebo from a starting point of about two to three.  That’s not bad. But it’s certainly not Love Potion #9.

So, how does it work? Well, the mechanism of action of Addyi is very similar to that which is seen in some types of anti-depressants. In fact, Addyi was originally developed as an antidepressant before being re-purposed and re-branded as a libido-boosting treatment for women with hypoactive sexual desire disorder. (I swear, that’s what it’s called. Thanks, Science!).  So, whereas Viagra acts on erectile tissue and not on the brain, Addyi acts on the brain and not on female erectile tissue (I swear, that’s what it’s called. Thanks, Science!).

Both Viagra and Addyi can have significant side-effects and neither should be used without a doctor’s prescription and supervision.  And certainly, neither should be purchased from an unregulated or online supplier.  That’s a recipe for disaster (or for Tiramisu, which also may have an effect on female sexual response, especially when eaten while watching Ryan Gosling).

So, now that you know a little more biochemistry, aren’t you kinda a little turned on?  I sure am.  Time to watch ‘The Notebook’ and eat some espresso-soaked ladyfinger cookies with mascarpone.

October 2, 2015 at 5:49 pm 2 comments