Quick Answers: Viagra Dosage at a Glance What doses does Viagra come in?25mg, 50mg, and 100mg tablets, with 50mg the typical starting dose. When should I take it?About 30–60 minutes before sexual activity; effects can last up to 4 hours. Can I get it without an in-person visit?Yes, through a licensed telehealth evaluation and online prescriber review. Who decides my dose?A licensed...