Viagra is FDA-approved to treat erectile dysfunction ... if needed, the maximum dose is 80 mg three times daily. Ages 18 and up (IV injection): 10 mg IV bolus injection three times a day Ages ...

If you’re prescribed Viagra, you can purchase it in doses of 25, 50, or 100 milligrams (mg). Hims recommends taking Viagra 30 minutes to 4 hours before sexual activity. You can make a one-time ...

Another difference is the dosage. 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.