Tylenol (acetaminophen) and Advil (ibuprofen) are both good medicines, and both provide relief from fever and pain, even though they have different chemical structures and side effects. Ibuprofen works by limiting the body's production of prostaglandins. In addition to reducing fever, body aches and pain caused by prostaglandins, ibuprofen also reduces inflammation (swelling and redness). Acetaminophen works primarily in the brain to block pain messages and reduce fever. That means it can help relieve headaches and minor pains, but it's not as effective against inflammation and the pain associated with it.
There are side effects specific to acetaminophen and ibuprofen. Taking too much acetaminophen can damage your liver, perhaps permanently. Prolonged use of ibuprofen can lead to kidney damage and stomach ulcers. Always consult your pharmacist or doctor to see which medication may be right for you. – Chris Norris, Home Infusion Clinical Pharmacist