Viagra, known as Sildenafil, is used to treat erectile dysfunction (impotence, the inability to get or keep an erection) in men. Viagra is taken before sexual intercourse and works by increasing blood flow to the penis, causing an erection. It is not good for men with heart problems, hypertension, recent stroke, or eye disorders. Viagra does not cure erectile dysfunction or increase sexual desire and does not prevent pregnancy, sexually transmitted infections or HIV. For safe sex, use condoms EVERY TIME.
Attribution: Straight Talk Foundation