ED medications can cause side effects, and it’s crucial to have access to a medical provider if needed. It might work longer if you have mild to moderate erectile dysfunction. This medicine also works best when you take it an hour before sex on an empty stomach. There are many safe, reliable online services offering ED prescriptions. Also, your doctor needs to review your medical history and make sure that you are not suffering from conditions that might be made worse by taking Levitra. Finally, we checked customer reviews to better understand user experiences with each platform.Oral medicines for ED usually work well and cause few side effects. The four main medicines taken by mouth for erectile dysfunction are: Avanafil (Stendra). Sildenafil (Viagra). Tadalafil (Cialis). Vardenafil. These medicines are called PDE5 inhibitors. Get sildenafil for as low as $, which is 99% off the average retail price of $ for the most common version, by using a GoodRx coupon. Prices Medicare Drug Info Side Effects Images Sildenafil (Viagra, Revatio) is a moderately priced drug used to treat erection problems in men. You should consult your health care professional before taking any drug, changing your diet, or commencing or discontinuing any course of treatment. Vardenafil is used to treat male sexual function problems (impotence or erectile dysfunction-ED). In combination with sexual stimulation, vardenafil w.