Acetaminophen and Your Liver: What’s Safe?

Medically Reviewed by Minesh Khatri, MD on May 14, 2023
3 min read

Chances are, acetaminophen is a mainstay in your medicine cabinet. You use it to ease aches and pains or bring down a fever.

When you follow the instructions on those pill-bottle labels, it's helpful and safe, and it generally doesn't upset the stomach like other pain relievers.

But if you take too much, it can hurt your liver. In extreme cases, it can even cause liver failure.

It’s still fine to use acetaminophen. You just need to know how to do that safely.

More than 50 million Americans use acetaminophen each week. It's the most widely used drug ingredient in the U.S., found in more than 600 prescription and over-the-counter (“OTC”) medications, including allergy pills, cold medicines, cough syrups, headache pills, and sleep aids.

Never take more than one product at a time that’s made with acetaminophen. For instance, if it’s in your headache pill and your cold medicine, and you take them both, you could get more than you should.

Check the “Active Ingredients” section of the “Drug Facts” box on your OTC medication, or the label on your prescription, where it may be called “APAP” or “acetam.”

Read the label on your medication. Don’t take more than directed, even if you’re still in pain or don't feel well.

Even when you stick to the recommended dose, you shouldn’t take acetaminophen for more than 10 days for pain, or 3 days for fever. If you still feel like you need relief, call your doctor, nurse, orpharmacist.

Adults should not get more than 4,000 milligrams of acetaminophen per day from all sources. That’s no more than 12 regular-strength pills at 325 milligrams per pill, or 8 extra-strength pills at 500 milligrams per pill.

For children, the daily limit depends on their weight and age. Check how many milligrams are in your child’s doses, and follow the directions on the label exactly.

You may need to switch your child’s weight from pounds to kilograms -- you can use an online calculator to do that. If you're not sure how much is OK, ask your doctor or pharmacist. To help you keep track, write down all the medicines you give your child each day.

Common reasons people mistakenly pass the daily limit include:

  • They take too much at once.
  • They don’t wait long enough between doses.

If you have more than three alcoholic drinks a day or have liver disease, ask your doctor before you take anything that has acetaminophen in it. In these cases, even the recommended dose could make liver damage more likely.

If you think you may have accidentally taken too much acetaminophen, you may have:

  1. Nausea
  2. Loss of appetite
  3. Vomiting
  4. Sweating
  5. Diarrhea

These symptoms may not start until hours after you've taken the drug. By the time you notice something’s wrong, your liver may already be severely damaged.

If you have questions about whether you took the right amount, call your local poison control center, which will tell you if you need to go to the ER. If you think someone may have overdosed, call 911.