Taking Viagra (sildenafil) as instructed may improve its effectiveness for erectile dysfunction. Viagra (sildenafil) is a common medication for erectile dysfunction (ED). .Avanafil Stendra. This medicine works best when you take it on an empty stomach an hour before sex. This medication is taken with or without food an hour before sex. How oral medicines differ Each oral medicine for ED has a slightly different chemical makeup. Such patients must not apply any out-of-pocket expenses incurred using this Savings Offer toward any government insurance benefit out-of-pocket spending calculations, such as Medicare Part D true out-of-pocket TrOOP costs You are responsible for reporting use of this Savings Offer to any private insurer, health plan, or other third party who pays for or reimburses any part of the prescription filled using this Savings Offer, as may be required.The Savings Offer and Program expire on 12/31/ For further information, call , visit , or write: Viatris Inc., P.O. Box , Mission, KS . generic Revatio and Viagra Used for Pulmonary Hypertension and Erectile Dysfunction MORE expand_more Check your prescription Prescription 20mg sildenafil (30 tablets) . If you’re interested in buying Viagra online, five of the best options available are Hims, Roman, Lemonaid, Optum Store, and REX MD. Read on for full details on the process .You can take this medicine with or without food 30 minutes before sex, depending on the dose. Avanafil Stendra. These medicines all work well for ED. You are encouraged to report adverse events related to Viatris products by calling U. You can take it in a small dose daily or in a larger dose as needed. It lasts 4 to 5 hours, or longer if you have mild to moderate ED.