The difference between a brand name medicine like Cialis and a generic one like Generic Cialis (Tadalafil) is in the name, shape and in the price. A generic drug like Generic Cialis is usually called by the name of the active ingredient Tadalafil while a manufacturer uses a brand name like Cialis. However, a manufacturer cannot possess a patent for a certain chemical agent, this is why manufacturers of generic medications like Generic Cialis can legally produce the so-called "generics". Generic Cialis is the same chemically as brand Cialis and since the active ingredient Tadalafil is identical, they have the same medical effect.