ED can sometimes signal an underlying medical problem, like heart disease or diabetes , that needs to be treated separately. Sildenafil Viagra. But, keep in mind that ED might signal an underlying medical problem, like high blood pressure, heart disease, diabetes, low testosterone, or sleep apnea. They’re often the first line of treatment for trouble getting or keeping an erection, called erectile dysfunction ED. You can take this medicine with or without food 30 minutes before sex, depending on the dose. Clinical trials for MED found minimal side effects. Pearlman says the availability of an easy-to-access treatment for men dealing with ED is welcome news.FAQ Takeaway We did a deep dive into five over-the-counter alternatives to Viagra to determine whether they work and how to use them. Maskot/Getty Images . 1. It Targets the Problem and Works Quickly. Being a topical means MED targets your penis directly and offers a “quick onset of action,” Dr. Pearlman . Avanafil (Stendra). Sildenafil (Viagra). Tadalafil (Cialis). Vardenafil. These medicines are called PDE5 inhibitors. They enhance the effects of a chemical the body .