Adults 65 years of age and older—25 mg as a single dose no more than once a day, 1 hour before sexual intercourse. You’ll soon start receiving the latest Mayo Clinic health information you requested in your inbox. Side Effects Along with its needed effects, a medicine may cause some unwanted effects. Place the tip of the syringe into you or your child’s mouth and point it towards the cheek. Do not keep outdated medicine or medicine no longer needed. · Viagra Prescribing Information. Package insert / product label. Generic name: sildenafil citrate. Dosage form: tablet, film coated. Drug class: Impotence Missing: criteria. RESOURCES GETTING STARTED WITH VIAGRA Your doctor has determined that VIAGRA may be right for you. Follow his or her instructions carefully to help you get the .  · 25 milligrams (mg) 50 mg mg Typical dosages The following information describes commonly recommended dosages for ED. However, be sure to take the .