When taken at the correct time and paired with sexual stimulation, the erection lasts long enough for successful intercourse. This allows the smooth muscles in the penis to relax and fill with blood. We considered cost, medications available, and whether generic versions were offered to help reduce costs. This information is reviewed by a licensed practitioner who will assess your eligibility for the medication. Read our editorial process. Erectile dysfunction can be caused by a variety of factors , including age, cardiovascular problems, diabetes, and other conditions that affect nerve function or blood flow. The most common symptoms of erectile dysfunction include difficulty achieving or maintaining an erection and reduced sexual desire.If you purchase medications online, be sure you are buying from a reputable and valid online pharmacy. Ask your health care provider for advice if you are unsure about the online purchase of any medication. See also: Generic Drug FAQ. Related patents. Lemonaid can prescribe sildenafil (generic Viagra), tadalafil (generic Cialis), and vardenafil (generic Levitra). You can get a prescription online following a quick and easy visit with a member of our clinical team. Quoted prices are for cash-paying customers and are not valid with insurance plans. This price guide is based on using the test1.ru discount card which is accepted at most U.S. pharmacies. A generic version of Levitra is available. See vardenafil prices (from $ for 2 .