How does Viagra work? Viagra works by stimulating an enzyme which controls the flow of blood to the penis called guanylate cyclase. Viagra releases the active ingredient nitric oxide into the penis and binds to the enzyme. This action leads to muscle relaxation around the arteries in the area resulting in a flow of blood to the penis and an erection. However, Viagra actually should not result in an erection unless there is sexual stimulation involved.

The primary use of Viagra is for the treatment of erectile dysfunctions and disorders. Erectile dysfunctions may be caused by trauma, an illness or side effects from other drugs, especially antidepressants. Sildenafil citrate, sold under the brand name Viagra, also treats the rare condition called pulmonary arterial hypertension. The drug helps relax the arterial wall which results in less pulmonary pressure. Viagra can also be used to treat high altitude pulmonary edema which results in people who are exposed to altitude sickness, mountain climbers for example. Some professional athletes even use Viagra as a way to increase blood flow to their muscles to enhance their athletic performance.

Since there are many people that have a hard time seeking a doctor’s care or who are unable to get insurance, these online pharmacies make it possible to purchase Viagra without leaving their homes and without getting a prescription. The drug’s quality is the same when purchased online, as the drugs cannot be labeled as Viagra without containing the same active ingredients. It is also usually a cheaper option to purchase the generic form of the drug, rather than paying for the brand name version sold by various drug companies.  You can buy Viagra online in various doses including 25 mg, 50 mg, and 100 mg pills. It is recommended that you purchase the lowest dose of Viagra that works for you, however all the Viagra doses available are safe.