How does Viagra Work?

There are muscles in the walls of the arteries that control the flow of blood into the penis. When these muscles tense up, the arteries contract, the blood flow into the penis decreases and it gets smaller. When these muscles relax, the arteries expand increasing the blood flow into the penis and it enlarges. If the arteries relax enough, the penis becomes erect.

Viagra causes the muscles in the arteries to relax. Viagra is not a kind of aphrodisiac. When a man is sexually aroused, an increase in blood flow to certain internal areas of the penis results in an erection. If the nerves or blood vessels in your genitals aren't working properly, you may not be able to get an erection.

Viagra is a phosphodiesterase-5 inhibitor drug, which treats erectile dysfunction by reducing the flow of the enzyme PDE-5 (phosphodiesterase-5) found in the spongy erectile tissue of the penis known as corpus cavernosum. As a result of this, more blood flows into the chambers of the penis which are located in its shaft. Viagra works by enhancing the effects of nitric oxide, a chemical, normally released into the penis during sexual arousal, allowing a man to get and keep an erection. Part of the physiological process of erection involves the release of nitric oxide (NO) in the vascular structure of the corpus cavernosum. NO (nitric oxide) speeds up the action of the enzyme guanylate cyclase which results in the increased levels of cyclic guanosine monophosphate (cGMP). It is this cyclic guanosine monophosphate (cGMP) which leads to smooth muscle relaxation in blood vessels supplying blood to the corpus cavernosum, resulting in increased inflow of blood and an erection.

In order to increase the effects of this anti-impotent drug you should avoid a high fat diet a couple of hours before taking Viagra, and if possible you should take Viagra on an empty stomach, because it's then that it works the best.

You should remember that Viagra is not a sexual stimulant or a libido enhancer drug. It aids the erection of a man only when he is sexually aroused. If a person does not feel interested in indulging himself in any type of sexual activity, even taking Viagra also will not be of any help to him. Viagra certainly increases your sexual performance, but not your sexual desire. You have to develop your mood for sex and its only then that Viagra would work wonders for you.

Why might Viagra not work?

Viagra has been found to be successful in mostly all the cases of erectile dysfunction but there are a few situations when Viagra may not work. One or more of the following reasons may be responsible for it:

• Viagra and similar medications are not effective for everyone; they do not work in about 1 in 5 people.
• There are several strengths of Viagra tablets. May be you need a higher dose.
• Eating a heavy, fatty meal can interfere with Viagra.
• May be you have not waited long enough for it to have an effect. It takes 30-60 minutes to work.
• You need sexual stimulation to have an erection with Viagra - you will not get an erection automatically.
• May be it is not a suitable treatment for you, but Cialis or Levitra might be effective.