When oral medications might not be safe Check with your health care team before you take any medicine for erectile dysfunction. This medication is taken with or without food an hour before sex. If you have an erection that lasts more than 4 hours, get medical help right away. Whilst some studies have suggested this, there is not enough evidence to support that Viagra is a suitable treatment for PE. Like with any medication, erectile dysfunction ED medications may not work for everyone that takes them. Therefore, you can feel safe knowing that the medications you are buying are from reputable wholesalers and genuine.Clinically proven to treat men with erectile dysfunction (ED) Ongoing commitment to product quality and safety monitoring Learn More IF YOU CHOOSE BRAND-NAME VIAGRA, . Sildenafil (Viagra, Revatio) is a moderately priced drug used to treat erection problems in men. It is also used to treat pulmonary arterial hypertension, a serious heart and lung . Sildenafil (Viagra). Tadalafil (Cialis). Vardenafil. These medicines are called PDE5 inhibitors. They enhance the effects of a chemical the body makes that relaxes .