Dec
Viagra is used to treat erectile dysfunction (impotence) in men. Another brand of sildenafil is Revatio, which is used to treat pulmonary arterial hypertension and improve exercise capacity in men and women. This page contains specific information for Viagra, not Revatio. Viagra comes as tablets that are taken by mouth. In most cases, it should be taken about an hour before sexual activity, but it can be taken 30 minutes to 4 hours beforehand. Viagra is available in three strengths: 25 milligrams (mg), 50 mg, and 100 mg.