Viagra (Sildenafil) is an oral drug used for treating male erectile dysfunction (impotence). Viagra enhances blood flow to the patient's penis, thus assisting the patient in achieving and maintaining an erection while being sexually stimulated. Viagra needs to be taken at least 30-60 minutes prior to sexual intercourse and the drug remains active in the body for 4 hours thereafter. Viagra may be taken as often as once a day.

Viagra is known to have mild side effects, if any. However, it should be noted that like most medications, it might not be suitable for all individuals and can be dangerous when used improperly. Viagra is approved for use by adult men only and should not be used by women.