Avanafil Stendra. Oral medicines for ED usually work well and cause few side effects. Make sure to get an estimate of when you can expect your prescription in the mail. People taking nitrates like nitroglycerin Nitrostat or isosorbide mononitrate Imdur should not take PDE5 inhibitors, as doing so could result in a dangerous drop in blood pressure. These drugs also have to be specially labeled, so many online pharmacy companies have already elected not to deliver them. Insurance: If you plan to use insurance, make sure the online provider accepts it.Sildenafil (Viagra). Tadalafil (Cialis). Vardenafil. These medicines are called PDE5 inhibitors. They enhance the effects of a chemical the body makes that relaxes muscles . Key takeaways: The best treatment for erectile dysfunction (ED) is the one that is best for you. Sildenafil (Viagra) and tadalafil (Cialis) are the most commonly prescribed . 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 with .