You can take acetaminophen every 4 to 6 hours as needed, but you should not exceed the maximum daily dose of 4,000 mg. Some experts recommend a safer maximum of 3,000 mg per day for those taking it daily. Taking too much acetaminophen can cause serious liver damage. Always consider other medications you take that might also contain acetaminophen to avoid accidental overdose. If you need to use acetaminophen regularly for chronic pain, it is best to consult a doctor.