How long does it take for a Tylenol to work after you take it?

I think up to like 1200mgs will stay in your system for 4-6 hours and break down progressivly after that.. but say for example a person had 10,000mgs in their system I think it would take minimum of 12-24 hours to completely process

** well if someone had 10,000 mg of acetaminophen in their system they would hopefully be under medical care. 10g of the substance is life threatening. Never take over 4g (4,000 mg) a day or there can be serious damage to your liver.