Viagra (sildenafil citrate) is a drug that is used to treat erectile dysfunction, or impotence, just like generic Cialis. Since its introduction in 1998, Viagra has proven a huge moneymaker for Pfizer; according to that pharmaceutical company, 9 tablets of Viagra are dispensed every minute. Viagra works by increasing blood flow to the penis, though not helping with penis enlargement. Viagra's effects can be felt within 30 minutes of taking a pill, the effects can last up to 4 hours, and Viagra can be taken as much as once per day.
Viagra has become a part of popular culture,
