Percocet, Vicodin, Other Combination Pills to Get Dose Limit, "Black Box' Warning
Source & More: webmd.com/painmanagementAcetaminophen, the active ingredient in Tylenol, is found in a wide range of over-the-counter and prescription drugs. At normal doses, when not taken with alcohol, acetaminophen is a very safe drug. But it's easy to take too much -- a big mistake that can lead to serious liver damage.