Although it would be unfair to compared penicillin and Viagra in the same breath, but the truth is that Viagra as a drug is perhaps the most purchased medicine in human history. Every year millions of dollars worth of Viagra is sold over the counter and on the Internet.

Since Viagra was initially developed as a drug to cure hypertension, in people not suffering from PAH (pulmonary arterial hypertension) Viagra does have a few side effects. The first side effect of Viagra is that it lowers the blood pressure, and it is possible for a person to overdose on Viagra (in fact this is why its a prescriptions drug). In rare cases Viagra can also impair liver function, however by and large Viagra if used judiciously is free from harmful side effects.

Sildenafil Citrate was originally developed to cure pulmonary arterial hypertension. It was during the testing of the product that test groups noted the drug was giving them erections. It was this side effect of Viagra that encouraged Pfizer to develop the most popular drug in human history.

Chemically Viagra is Sildenafil Citrate, and the drug works by improving the blood circulation in the muscles that are responsible for erections (corpus cavernosum). Unlike other scheduled drugs Viagra does not require a doctors prescription and can be purchased over the counter in most countries the world over. In the US however a person requires a prescription to purchase Viagra, and over the counter selling of Viagra is illegal in the US.

Viagra tablets are available in three doses 25mg, 50mg and 100mg. Depending on the dosage a patient is usually advised to take a pill 30 minutes to 4 hours before sexual intercourse. Another common misconception is that consuming Viagra alone can give people erections; this is not the case just like a normal erection mental and physical stimulation is also important.

Viagra is one of the leading drugs in treating erectile dysfunction or impotence, and the mechanism of action is a little too complicated for the scope of the article. But by and large if a person is not suffering from any physical failure in the corpus cavernosum Viagra can help people enjoy a healthy and normal sex life.

There are also other drugs available that hope to become alternatives to Viagra. Two such drugs are Cialis and Levitra. No matter what drug one uses it is always advisable to consult a physician before using Viagra as some people can be at high risk by using Viagra, a good example is people that are undergoing treatment for hypertension.

Today one of the convenient ways of get Viagra is go online, all a user has to do is log on to a licensed online pharmacy website and fill out a consultancy form.