No other drug could give a real run to the men with impotence as Viagra do. It is more because of the fact that with Viagra, men understood that erectile dysfunction is a physical condition and this condition can be treated. Today, a man understands that the blood flow to the penis is the main mechanism behind erection and Viagra works by relaxing the penile muscles and thereby helping in increased blood flow into the penis. Viagra was the first to address the issue of male sexual health; erectile problem is an important medical phenomenon today which is closely related to other more serious conditions of heart, veins and blood pressure. The sexual lives of millions of men throughout the world have experienced a renaissance.

But sexual stimulus is needed for Viagra to work. The likely trigger for nighttime erections, is said to be the strongest sexual stimulus a man can experience. The brain shuts down all other activity to the penis and the level of adrenaline, which interferes with erections.

An study of 44 men gave half the men 50 milligrams of Viagra before they went to sleep. The men averaged 39 years of age and didn't have erectile dysfunction. Those who took Viagra had significantly longer and more stronger nighttime erections than the men taking a placebo. Men who are regular users of Viagra say the pill has been a life-changing experience.