Getting a Prescription. Download Article. 1. Make an appointment with your doctor. There are online sources that will provide “Viagra” without a prescription, but this is an illegal .Its effects might last longer if you have mild to moderate ED. Recent heart or blood vessel problems. Telehealth How much does a visit cost? Your medical information is kept private and secure. Friday Plans makes it possible to get ED treatment quickly and securely, with just a handful of clicks on your phone, tablet, or computer.Cost Pregnancy Birth control needs Breastfeeding For professionals Drug Images What is Viagra? Viagra is a brand-name prescription drug that’s approved to treat erectile dysfunction (ED). With. Getting a Prescription. Download Article. 1. Make an appointment with your doctor. There are online sources that will provide “Viagra” without a prescription, but this is an illegal . Sildenafil (Viagra) is a medicine used to treat erectile dysfunction (ED, also called impotence). Sildenafil works by helping to relax the blood vessels in the penis, allowing more blood to flow in and cause an erection. You should take sildenafil about an hour before planned sexual activity, so it has time to work.This medication is taken with or without food an hour before sex. Efficacy Results in Subpopulations in Controlled Clinical Studies A review of population subgroups demonstrated efficacy regardless of baseline severity, etiology, race and age. Side effects Side effects of oral ED medicines are often mild. Rarely reported side effects include: an erection that will not go away priapism. What if I want to have my prescription filled at another pharmacy?