There are three different doses of Viagra. The pills are available in strengths as high as 20 mg, and hangs around your bloodstream for up to 36 hours. Viagra Still the leading brand in ED pills, Viagra should be taken at least an hour before sex and on an empty stomach. This tends to be more affordable, but it has the same safety profile and efficacy as the branded drug — and is available in the same dosages. Does your partner have any sexual problems? If medication is prescribed, is there a generic alternative? If we combine this information with your protected health information, we will treat all of that information as protected health information and will only use or disclose that information as set forth in our notice of privacy practices.Q&A. Drug Images. Viagra (sildenafil) is a prescription drug that’s used to treat erectile dysfunction (ED). The drug comes as a tablet you’ll take by swallowing. It’s usually taken as needed. Sildenafil (Viagra, Revatio) is a moderately priced drug used to treat erection problems in is also used to treat pulmonary arterial hypertension, a serious heart and lung drug is more popular than comparable drugs. It is available in generic and brand versions. Generic sildenafil is covered by most Medicare and insurance plans, but . AdGet a Prescription for ED treatment, discreetly deliverED to your e Catalog: Instagram, P.E. Treatments, GET MORE INFO, Terms & Conditions and more.