This includes prescription or nonprescription over-the-counter [OTC] medicines and herbal or vitamin supplements. Sildenafil comes as a tablet and suspension liquid to take by mouth. If you are taking sildenafil for erectile dysfunction, you are unlikely to miss a dose since this medication is taken as needed, not on a regular dosing schedule. The usual adult dose is 20mg taken 3 times a day. Do not take it more than 3 times a day. Also tell your doctor if you or any of your family members have or have ever had an eye disease such as retinitis pigmentosa an inherited eye condition that causes loss of vision or if you have ever had sudden severe vision loss, especially if you were told that the vision loss was caused by a blockage of blood flow to the nerves that help you see.These drugs are dubbed “female Viagra,” as a play on the medication for men to alleviate erectile dysfunction. They work in the body in different ways and are also administered . 1 day ago · Hims is a telehealth company that provides both prescription and over-the-counter generic and brand-name medications. The brand focuses mainly on five medications, including Viagra, that have. The Food and Drug Administration (FDA) has not approved Viagra for use in women. But your doctor can prescribe it for off-label use. Like all drugs, Viagra can cause side .