How does Tylenol (acetaminophen) poisoning affect the body?

If you take more than the safe, recommended dose of 4 grams of acetaminophen per day, liver damage can take place. This is because some amount of the drug becomes a toxic substance, called a metabolite, as it gets processed in the body. This metabolite can attach to liver proteins, causing damage to the liver cells. When too much acetaminophen is taken, this damage becomes serious. Severe overdoses can cause acute liver failure, and in some cases, death.