Viagra is an oral drug for male impotence, also known as erectile dysfunction. Having been around for a lot longer, Viagra has a great safety track record and proven effects that start acting in 30 minutes and last for about 5 hours.

Viagra is used to treat impotence in men. It increases the body's ability to achieve and maintain an erection during sexual stimulation.

Viagra should be taken as needed about 1 hour before sexual activity. However, Viagra can be taken anytime from 4 hours to 30 minutes before sexual activity.

Viagra is a phosphodiesterase inhibitor. It works by helping the blood flow into the penis to achieve and maintain an erection.