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. If approved, the provider will issue a prescription. Most erectile dysfunction medications belong to the drug class known as PDE5 inhibitors , which help relax the muscles and increase blood flow to allow for a full erection. Online pharmacies also may not fill short-term prescriptions, such as those for antibiotics. They have the same benefits and risks as their brand-name counterparts.AdWith RexMD you’re saving time and money with our ED delivery. Get started now. Reliable E.D. meds prescribed by real doctors. Get your free & private online visit todayFree Shipping · Discreet Packaging · Real Doctors · Personalized PlanSexual health: Premature Ejaculation · Erectile Dysfunction · Breakouts. Viagra (, 50, 25 and 20mg) takes about 30min to have full effect but cannot be taken with food, as it can diminish the result. The 20mg dose can also be compounded at . There is generic Viagra now. They have 20mg and mg tablets. It’s usually $/bottle depending on your pharmacy. 2. ClandestineUs. • 5 yr. ago. Wow! What’s the name? 2.