There are many safe, reliable online services offering ED prescriptions. Finding an online ED provider can feel overwhelming. Tadalafil requires a prescription. Refills: See if you can set up automatic refills or order as needed. A higher dose of tadalafil is needed if your body does not respond to the recommended dose. Likewise, if you experience side effects, we may recommend that you try a lower dose of Tadalafil.Traditional ED treatments like sildenafil (Viagra), vardenafil (Levitra, Staxyn), and tadalafil (Cialis) are often also used to treat pulmonary hypertension. Cialis (tadalafil) is an expensive drug used to treat erection problems in men. It may also be used to treat the enlargement of the prostate gland. This drug is slightly more popular . Cialis is a popular ED medication. Find out everything you need to know about this doctor-prescribed medication including usage, effectiveness, and safety .