It’s never fun to deal with a throbbing headache, achy joints, or a slight fever. These health issues might be minor, but they can take the joy out of your day. Thankfully, you can use an over-the-counter (OTC) pain medicine to feel better. But which of the two most popular remedies — acetaminophen and ibuprofen — should you choose?

Both can be bought at your local pharmacy or grocery store. You probably have a bottle of one or both at home already. And both work well. But depending on your symptoms, one might be better than the other.

Our guide can help you figure it out. You’ll find out how each pain reliever works and learn what’s best for your symptoms.

What is acetaminophen?

Acetaminophen is an ingredient used to lower high body temperatures and ease pain. It’s sold as Tylenol® and other brand names. It’s also used with other ingredients in remedies such as:

• Multi-symptom cold medicine.
• Sleep aids.
• Prescription pain relievers.

“Acetaminophen works in the brain,” says Marie N. Hanna, M.D. Dr. Hanna is the medical director of the peri-operative pain program at Johns Hopkins University in Baltimore. Acetaminophen works by blocking chemicals that cause the feeling of pain and fever.

Adults usually take acetaminophen as a pill or capsule. It takes about 30 to 45 minutes to kick in. And it can last 4 to 6 hours, says Dr. Hanna. You can take it every 4 to 6 hours as needed without going over 3,000 mg a day. More than that can damage your liver. If you have a liver condition, talk to your doctor before taking acetaminophen.

What is ibuprofen?

Ibuprofen is part of a class of medicines called nonsteroidal anti-inflammatory drugs (NSAIDs). Popular brands include Advil® and Motrin®. Ibuprofen is also used to lower fevers and ease pain. Bonus: It also lowers inflammation.

Ibuprofen works both in the brain and the body. It also blocks pain chemicals. These OTC medicines last about 4 to 6 hours. And you can take them 3 to 4 times a day if needed.

How do I know which one to choose?

In most cases, the decision comes down to your personal choice. That said, there are some times one may be better than the other.

Treating inflammation. Ibuprofen is better than acetaminophen for treating inflammation. So it's the better choice if you have:

• Joint and muscle pain.
• A toothache.
• Menstrual cramps.

When you’re taking another medicine. Mixing medicines can be dangerous. Both may interact with other medicines you take.

“Many patients on blood thinners can’t take ibuprofen. It can cause heavy bleeding,” says Yomna Nassef, M.D. Dr. Nassef is a spokesperson for the American College of Emergency Physicians. Check with your doctor if you regularly take other medicines.

Is acetaminophen your pain reliever of choice? If so, don’t take more than 1 medicine with acetaminophen at a time, says the U.S. Food and Drug Administration. Taking too much can cause liver problems.

Before and after surgery. Having root canal surgery? Recovering from a knee operation? Save the pain reliever until your doctor gives the okay. The reason: Ibuprofen thins your blood. It can cause bleeding and bruising. And while acetaminophen is generally ok after surgery, it can mask a fever or infection.

You should always tell your doctor if you take these medicines and are having surgery. They will likely tell you to stop any OTC pain relievers until after the operation.

Young children. Ibuprofen isn’t recommended for children under 6 months old. And a pediatrician should approve ibuprofen use for babies under age 2. Acetaminophen may be safe for children as young as 12 weeks old.

Both medicines come in a children’s version. And the dosage amount will be based on your baby’s weight. Check with your pediatrician before giving your child either medicine.

Stubborn pain. Have pain that just won’t go away? Both medicines working together might do the trick. “Alternating pain relievers every 3 hours is a great strategy for patients with pain conditions,” says Dr. Nassef. Talk to your doctor to be sure you make a safe medicine plan.

Understand the side effects.

Both ibuprofen and acetaminophen are generally safe if you take them correctly. But as with all OTC medicines, they may have side effects. “Some can even be dangerous if you’re not careful,” says Dr. Nassef.

Possible side effects of acetaminophen include:

• Nausea.
• Vomiting.
• Constipation.
• Abdominal pain.
• Itchy skin.
• Allergic reactions.
• Liver problems. (This can happen if taken in large doses, over long periods of time, or with alcohol.)

Possible side effects of ibuprofen include:

• Constipation, diarrhea, gas, and bloating.
• Dizziness.
• Ringing in the ears.
• Nervousness.
• Ulcers and stomach issues. (This can happen if taken in large doses, over long periods of time, or with alcohol.)

To stay away from side effects, follow the dosing directions on the bottle. Have questions or side effects? Talk to your doctor.

SOURCES:

[1] “Don’t Double Up on Acetaminophen.” U.S. Food and Drug Administration. September 10, 2018,  https://www.fda.gov/consumers/consumer-updates/dont-double-acetaminophen. Accessed January 12, 2023.

[2] “Ibuprofen (Oral Route).” Mayo Clinic. January 1, 2023,

https://www.mayoclinic.org/drugs-supplements/ibuprofen-oral-route/precautions/drg-20070602. Accessed January 12, 2023.

[3] “Ibuprofen Dosing Table for Fever and Pain.” American Academy of Pediatrics, October 21, 2021, https://healthychildren.org/English/safety-prevention/at-home/medication-safety/Pages/Ibuprofen-for-Fever-and-Pain.aspx. Accessed January 12, 2023.