You’ll also need to fill out a medical questionnaire with answers about your medical history, current medications, and lifestyle habits. Stendra avanafil : This is an as-needed medication taken 30 minutes before sex and can last up to six hours. Finding an online ED provider can feel overwhelming. You can see an in-person provider or speak with a doctor virtually. All PDE5 inhibitors, including Viagra and Cialis, require a valid prescription regardless of the pharmacy or provider.Sildenafil is a generic drug, which is an exact copy of the active drug in a brand-name medication. The generic is considered to be as safe and effective as the original drug. And generics tend to. Get sildenafil for as low as $, which is 95% off the average retail price of $ for the most common version, by using a GoodRx coupon. Prices Medicare Drug Info Side Effects Images Sildenafil (Viagra, Revatio) is a moderately priced drug used to treat erection problems in men. Cost: Consultation prices vary based on the prescriber; $5 generic prescriptions Medical Consultation Required: Yes Medications Prescribed: Viagra, Cialis, sildenafil, tadalafil Generic offered: Yes Why We Chose ItMissing: cheap.