Medicines that you take by mouth are called oral medicines. Your healthcare provider can help you determine the right dosage for you. However, eating food, particularly high-fat food, can reduce the effectiveness of Viagra. Viagra is always taken as needed, usually about an hour before sex. If you are experiencing any of these or develop a painful erection that lasts more than 4 hours, please get medical attention right away. You can take this medicine with or without food 30 minutes before sex, depending on the dose. Recent heart or blood vessel problems.Generic Viagra (sildenafil): $4 per 25 mg pill, $6 per 50 mg pill, $10 per mg pill; Generic versions cost much less than the brand-name options, and insurance isn’t accepted. Generic Viagra (sildenafil): Starting at $24/month; Generic Cialis (tadalafil): Starting at $39/month;. The Savings Offer and Program expire on 12/31/ For further information, call , visit , or write: Viatris Inc., P.O. Box , Mission, KS See risks & benefits. Learn more about what VIAGRA® (sildenafil citrate), a prescription treatment for ED.  · Viagra is usually taken only when needed, 30 minutes to 1 hour before sexual activity. You may take it up to 4 hours before sexual activity. Do not take Viagra more than once per day. Shake the oral suspension (liquid) before you measure a dose. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).