So you wanted to get technical huh? You want to know exactly how Viagra, or specifically Sildenafil Citrate creates the turgid erections that men around the world are swearing by. Fair enough, hold on to your hats, get your chemistry books open, and watch out for High School flashback.
The short answer and simple answer to the question of how Viagra works is that it simply relaxes the soft muscle in the penis to allow greater blood flow from the arteries and create harder, longer lasting erections. You knew that already though, you’ve read that over and over again. You want to know what’s really happening inside your body, so here goes.
The story of an erection begins with arousal in the brain. In order for a man to have an erection, the valves that control blood flow to the penis must be open, and the brain controls the function of these valves. It does this by sending messages down a nerve fibre. This nerve fibre ends in something called an NANC nerve cell which is in the artery, and located near the valve that the brain needs to control.
When the NANC cell recieves the message, it injects nitric oxide into the surrounding blood and cells, which stimulates an enzyme known as guanylate cyclase and causes it to start producing cyclic guanoine monophosphate, otherwise known as cGMP.
CGMP is the magic little chemical that tells the smooth muscle to relax and opens the valves. IF the cGMP has been produced near the penile valves, then lo and behold, the man gains an erection.
Loosing an erection is also fairly simple, another enzyme is produced, phosphodiestrase (PDE) which turns off the cGMP and causes the valve to close up again. This is manifested in the penis becoming limp and flaccid once more.
Now you know the basic process, it’s time to disclose what often happens when a man is experiencing erectile dysfunction. The most common cause appears to be a lack of cGMP, for one reason or another, the man simply does not produce enough to keep the valves open, and the PDE kicks in, slowing the arterial blood flow to the penis, and causing love making to become impossible regardless of arousal.
It’s a difficult problem to solve, but Sildenafil Citrate does it very neatly. It works not on the cGMP, but on the PDE which causes the valves to shut down. Of course, a pill that acted unilaterally on PDE throughout the body would have some very unpleasant and bizzare effects. Luckily for men who experience erectile issues, there are different forms of PDE that are produced throughout the body, and there happens to be a very specific form that is produced in conjucntion with the penile valves, known as PDE5.
What Sildenafil Citrate does is target PDE5 and block its production, allowing the valves that supply the blood which maintains an erection to stay open for the duration of erotic activity as determined by the arousal the man experiences in his own mind. Devilishly simply, and terribly complicated all at the same time.