Food and Drug Administration has approved fifteen drug manufacturers to market generic sildenafil in the United States. If you prefer, you may contact the U. This site is intended only for U. On 6 May , Pfizer , which manufactures Viagra, told the Associated Press they will begin selling the drug directly to people on its site. This patent was published in and expired in Generic Viagra Sildenafil Switch to brand medication info_outlined Used for Erectile Dysfunction MORE expand_more Check your prescription Prescription mg sildenafil . Q&A Drug Images What is Viagra? If you have erectile dysfunction (ED), your doctor may recommend that you take Viagra. It’s a prescription drug that’s used in . Viagra (sildenafil) is a brand-name oral tablet prescribed for erectile dysfunction. The cost of the drug with and without insurance can depend on several .