Your doctor may adjust your dose if needed. It might work longer if you have mild to moderate erectile dysfunction. If we combine this information with your protected health information, we will treat all of that information as protected health information and will only use or disclose that information as set forth in our notice of privacy practices. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine. Medicines that you take by mouth are called oral medicines. Different brands may not work the same way. Use only the brand of this medicine that your doctor prescribed.Products and services Erectile dysfunction: Viagra and other oral medications By Mayo Clinic Staff Medicines that you take by mouth are called oral . Consumer Reports Best Buy Drugs shares how you might be able to get generic Viagra, known as sildenafil, at a much lower price.  · There’s a Free, Low-Risk Alternative to Viagra, Study Shows. Regular exercise sessions can be as effective as popping Viagra pills when it comes to dealing .