You can take it in a small dose daily or in a larger dose as needed. However, the dose is usually not more than 80 mg 3 times a day. Your partner can help you remember something that you missed or forgot during the appointment. When oral medications might not be safe Check with your health care team before you take any medicine for erectile dysfunction. Brand names Why is this medication prescribed? Do not press on the plunger of the syringe. What special dietary instructions should I follow?Sildenafil (Viagra). This medicine works best when you take it on an empty stomach an hour before sex. The body takes longer to absorb it after a high-fat meal or alcohol. Its effects often last for 4 to 5 hours. It might work longer if you have mild to moderate erectile dysfunction. Vardenafil. Viagra for ED. Viagra is FDA-approved to treat erectile dysfunction (ED) in males ages 18 years and older. With ED, you’re not able to get and keep an erection that’s firm enough to have sex. The Savings Offer and Program expire on 12/31/ For further information, call , visit test1.ru, or write: Viatris Inc., P.O. Box , Mission, KS See risks & benefits. Learn more about what VIAGRA® (sildenafil citrate), a prescription treatment for ED.