Both options require valid medical documentation, but some online services only require a health questionnaire to be filled out and reviewed for approval—meaning no face-to-face video interaction is needed. This allows the smooth muscles in the penis to relax and fill with blood. What Are the Symptoms of Erectile Dysfunction? Those who don’t feel comfortable discussing ED with an in-person provider or lack time to visit a doctor’s office may find online ED prescriptions beneficial. Vardenafil usually works for 4 to 5 hours. People with heart conditions should never take ED medications without consulting a doctor. Here are some key factors to consider when deciding: Pricing: Know how much your monthly supply will cost with shipping and tax.can start in about 10 minutes, can take 1 hour for maximum effect. typical starting dose is 50 mg, can be increased to mg. Tadalafil (Cialis) when you need it, . When choosing one, tell your doctor or other health care professional what your preferences are, such as cost, ease of use, how long the drug’s effects last and . Prices for popular Erectile Dysfunction medications Viewing 8 of 8 medications Popularity arrow_drop_down Cialis (tadalafil (Cialis)) as low as $14 View other PDE5 .