Side effects Side effects of oral ED medicines are often mild. Popular ED medications found online include: Viagra sildenafil : As the first FDA-approved PDE5 inhibitor for ED, sildenafil is taken 30 minutes to four hours before sexual intercourse to help achieve and maintain an erection. Your health information should remain between your provider and yourself. It may be difficult to remain firm despite wanting to have sex. This information is reviewed by a licensed practitioner who will assess your eligibility for the medication. Oral ED medicines might not work or might be dangerous if you also take any of the following: Nitrate medicines.CHOOSE BRAND-NAME VIAGRA. The original little blue pill prescribed by doctors for over 20 years. Clinically proven to treat men with erectile dysfunction (ED) Ongoing . atherosclerosis. DRUG_DESCRPTION Compare DRUG_NAME prices and find coupons that could save you up to 80% instantly at pharmacies near you such as CVS, Walgreens, Walmart, and .