Our erectile dysfunction Rx options We offer prescription medications clinically proven to help improve erections. See our source here What is Tadalafil? Why is it called generic Cialis? We prescribe 3 different doses: 5mg, 10mg and 20mg. Get started by completing an online visit.Results Prescription Required Tadalafil (Generic for Cialis) Tablets · 20mg · 6-day supply With insurance est. $ Estimated insurance price. Final price varies with your insurance. Without insurance $$ Prime member price, 6-day supply. FREE delivery Prescription Required Sildenafil (Generic for Viagra) Tablets · mg · 6-day supply. Generic Cialis, or Tadalafil, is available in several doses in tablet form: milligrams (mg), 5 mg, 10 mg, and 20 mg. Depending on the dose for ED, you can use it as needed before. Amazon Pharmacy: Tadalafil (Generic for Cialis, Oral Tablet).us. Account Returns& Orders. Cart. Transfer your prescription for Tadalafil (Generic for Cialis, Oral Tablet) .