Probably 2 vials, maybe 3. Don’t sweat it, it’ll be over in 10 minutes or less. Don’t watch the needle go in, look the other way. Clutch the desk tightly if needed. This is my routine lol. Be SURE you’re well hydrated and be mindful of your hydration a couple days before your draw vs drinking a bunch of water in the parking lot before you go in. You’ll do fine.