The medical consensus appears to be that Tylenol is safe for healthy people as long as the recommended dosage is not exceeded. Furthermore, in the case of children, the use of Acetaminophen is credited with reducing the occurrences of Reye's syndrome. On the other hand, overdosing on Tylenol can cause liver failure. Similarly, long-term use of Tylenol may be associated with liver disease based upon some studies done in the 1970s. Some of these subjects; however, may have had undiagnosed hepatitis C which contributed or may even have caused the liver damage. Most physicians currently believe that use of Tylenol does not cause significant liver damage in healthy individuals unless it is taken in excess of the recommended dosage.
In any event, if you regularly use Tylenol and you develop liver problems, consult your lawyer, umm. doctor, as soon as possible.