Tylenol (acetaminophen) is the most popular over-the-counter (OTC) pain relief medication in the United States. It is manufactured by Johnson & Johnson's subsidiary McNeill Laboratories. Studies have shown that Tylenol over-consumption may cause acute liver failure.
Unlike prescription acetaminophen, Tylenol is not subject to the Food and Drug Administration's (FDA) limitation of 325mg-per-dose. OTC Tylenol, including Extra Strength Tylenol tablets, contain more than the allowed dosage. Extra Strength Tylenol tablets contain 500mg each, and the directions instruct consumers to take 2 tables every 6 hours.
The FDA required a new warning to be added to the caps of bottles of Extra Strength Tylenol warning consumers that the drug contains acetaminophen and may cause liver failure. Over 200 cases are still pending resolution.