Severe liver disease. Remember that expediting will cost extra. Sildenafil Viagra Sildenafil, commonly known by its brand name Viagra, is perhaps the most well-known and widely used best ED meds online. Still other online pharmacies specialize in medications for only a select few health concerns or conditions. First and foremost, be sure that whichever online pharmacy you choose is legitimate, safe, and secure. Generic medications contain the same active ingredients and are equally effective but are often more cost-effective. Wineinger, Nathan E et al.$ retail Save 94% $ Get free savings Low price Walgreens $ retail Save 94% $ Get free savings directions Closest store Rite Aid. Typical dosing for Sildenafil (Viagra) The typical dose is to take 50 mg of sildenafil (Viagra) by mouth, about 1 hour before sex, as needed. The maximum recommended . Viagra is sold under the generic name sildenafil, which is also only available with a prescription. Many medical clinics now offer remote health services where you can .