The drug sildenafil citrate, sold under the brand name Viagra was introduced in the market by Pfizer, Inc., one of the largest pharmaceutical companies in the world today. Viagra blindness.

It is commonly used to treat erectile dysfunction, a health condition whether men, especially those in their senior years, find it difficult to have an erection or to maintain it during sexual intercourse.

While Viagra is very much well known for its intended use as well as its common side effects and the health risks involved when taking the drug, there are still other interesting facts about the drug that very few people know.

1. Sildenafil Citrate is the generic name of Viagra® and it is mainly used to treat erectile dysfunction in men. However, since the time it was first introduced, no generic Sildenafil tablet has ever been made available. The so-called "generic sildenafil" or "generic Viagra" is for sure an illegally manufactured or counterfeit product.

2. Viagra is one of the best known medical drugs all throughout history. Searching the word "Viagra" over the engine Google (www.google.com) would end up with over 17 million web pages as compared to the 3.3 million web pages that has the word "aspirin" or the 936,000 with "Tylenol".

3. There are more spam email messages that advertise Viagra more than any other product amounting to more than a billion daily. The huge volume of spam e-mails has caused Pfizer to have a page on its website (www.viagra.com) that specifically addresses the problem of fake Viagra and counterfeit online pharmacies.

4. The Viagra product name is so popular that almost every adult male in the United States have heard about it and can correctly identify what it does. There are more than twenty million men from different countries around the world that use Viagra regularly. One of every five men in the United States over the age of 40 has tried the drug.

5. Viagra is also one of the most commonly purchased medical drugs in the world. Every second, an average of nine Viagra tablets are dispensed, amounting to more than 300 million tablets annually.

6. The three scientists who developed the drug Viagra, Louis J. Ignarro, Dr. Ferid Murad, and Robert F. Furchgot received the Nobel Prize in Physiology or Medicine in 1998 by proving that nitric oxide serves the role of a signaling medium among cells in the cardiovascular system. This medical truth is the key principle behind the development of Viagra.

7. For best results, one should take Viagra orally at least an hour before intercourse or at least half an hour before you would want to have an erection. Its effects are expected to last for at least four hours.

8. Viagra tablets can also be used in treating other diseases such as pulmonary hypertension and other cardiac conditions such as Raynaud's phenomenon. It can effectively lower one's blood pressure by dilating the walls of the heart arteries.

9. Despite what many people think, Viagra is not an aphrodisiac and it will not be effective unless there is proper sexual excitement or one is sexually stimulated.

10. Viagra, despite being priced at an average of ten US dollar each, is one of the best selling medical products with generated total sales of over two billion US dollars worldwide. With all of the above why not buy Viagra online cheap without the need for a Doctor's prescription.