How Viagra Works

Viagra is a medicine used to treat erection difficulties, such as erectile dysfunction (ED). Viagra works by blocking an enzyme called phosphodiesterase-5, or PDE-5. This helps the smooth muscles in the penis to relax and widen, which allows for more blood to enter. With the widening of penis muscles and increased blood flow the erections are bigger and harder. So the result is faster and easier erections.

There are however some misconceptions regarding the functioning of Viagra. Simply taking Viagra won't give you an erection. Even after you take Viagra you need to be stimulated sexually to achieve an erection. Once you ejaculate, the erection goes off as it happens naturally. Ideally Viagra can work in as quickly as 30 minutes. Viagra works for at least 4 hours so you can set your own pace. In most patients, Viagra can be taken as often as once a day.

To know more about how an erection occurs check the following link:

Anatomy of penis

Physiology of erection