Viagra is FDA-approved to treat erectile dysfunction ... Ages 18 and up (IV injection): 10 mg IV bolus injection three times a day Ages 1 year or older, 20 kilograms (kg) or less: 10 mg by ...

Viagra costs $90 to $139 per tablet. Generic sildenafil can range from $2 to $10 per pill, depending on the manufacturer and dose.

Each medication has its own dosage meter. Viagra doses are 25 milligrams (mg), 50 mg, and 100 mg. Cialis and tadalafil doses are 5 mg, 10 mg, and 20 mg. Cialis also has a lower dose of 2.5 mg that ...