Levitra vardenafil : This medication is taken one hour before sex and can last up to 24 hours. Other warning signs of an unsafe online pharmacy include outdated medication, no customer service, or suspiciously low prices. Insurance can help you save even more on consultations and medications. Erectile dysfunction medications require a prescription from a licensed provider. Online telehealth services like Lemonaid offer you both safety and convenience.How do ED medications work? Viagra, Cialis, Levitra, and Stendra are all in a class of medications called phosphodiesterase type 5 (PDE5) inhibitors. These drugs . Cialis (tadalafil) is an expensive drug used to treat erection problems in men. It may also be used to treat the enlargement of the prostate gland. This drug is slightly more popular .