How many milligrams of Tylenol can you take at a time?

Tylenol contains acetaminophen. The maximum daily dose of acetaminophen must not exceed 4000 mg ('daily' means 24 hours). It is not recommended to take more than 1000 mg of acetaminophen at a time. The interval between 1000 mg doses should be about 6 hours. 500 mg doses can be taken more frequently, e.g. every four hours.

Each Tylenol 500 gelcap, etc, contains 500 mg of pure acetaminophen. So, the daily maximum is 8 doses of Tylenol 500, not more than two doses at a time. The less, the better, as acetaminophen is not good for the liver.