Excedrin contains both acetaminophen and aspirin. Both of these are common pain killers, but most people take them separately. Tylenol is a common brand name for acetaminophen and aspirin is often sold under the brand name of Bayer. Excedrin also contains another ingredient that is known to reduce headaches, which is caffeine. Advertising for Excedrin focuses on migraine headaches and how this pain medication relieves them. Excedrin Migraine has about the amount of caffeine that is contained in a cup of coffee. According to WebMD, caffeine is added to combination headache medications like this one because it speeds up the action of the acetaminophen and aspirin.