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. An erection results from an increase in blood flow to the penis. It’s available in 10 mg and 20 mg tablets. Lemonaid can prescribe sildenafil generic Viagra , tadalafil generic Cialis , and vardenafil generic Levitra. Then the Lemonaid pharmacy, licensed in all 50 states, will ship your meds directly to your door in discreet packaging.Lemonaid can prescribe sildenafil (generic Viagra), tadalafil (generic Cialis), and vardenafil (generic Levitra). You can get a prescription online following a quick and easy visit . Generic name: sildenafil (oral) [ sil-DEN-a-fil ] Brand names: Revatio, Viagra. Drug class: Impotence agents. Medically reviewed by Sophia Entringer, PharmD. Last updated on . Best Low Cost: GoodRx. Fastest Delivery: Blink Health.: Sesame. Sign Up Now. Key Specs. Cost: Consultation prices vary based on the prescriber; $5 generic prescriptions. .