What works best for a child’s fever? A child’s fever is one of the most common reasons for doctor visits. There are only a couple of medicines that are safe for infants; ibuprofen (aka Motrin) and acetaminophen (aka Tylenol, paracetamol). So, what’s the evidence?

Recent studies include a 2020 meta-analysis of all the best studies, evaluating 240,000 kids in 7 countries, comparing the two meds with children. It showed that ibuprofen is clearly better than acetaminophen in terms of more rapid effectiveness, as well as lasting a bit longer. Here’s the graph for fever relief over 4-24 hours:

The same went for pain relief, with ibuprofen again a clear winner for short term treatment of 4-24 hours, and each one about the same after 1 day. Here’s the graph:

Here’s their conclusion:

Our review of acetaminophen or ibuprofen for fever or pain in children younger than 2 years found moderate-quality evidence that compared with acetaminophen, ibuprofen was associated with reduced temperature at less than 4 hours and at 4 to 24 hours and less pain at 4 to 24 hours. The superiority of ibuprofen as an antipyretic did not continue beyond 24 hours after treatment onset. No data were available on analgesic outcomes at less than 4 hours. Our review found low-quality to moderate-quality evidence that acetaminophen and ibuprofen have a similar safety profile with respect to SAEs, kidney impairment, GI bleeding, hepatotoxicity, and asthma and/or wheeze at 28 days or less. Overall, adverse events were uncommon or rare, with most studies reporting no events.

Ibuprofen probably works better because it’s also anti-inflammatory, while acetaminophen is not. But both are so safe, and so commonly used, that you certainly should try both to see which may be more effective.

By the way, both medicines have very different chemical structures and can be used together — just make sure it’s the right dose. Some parents like to alternate every 4 hours, and that’s fine as well. You can also use both together, at the same time, if your child is miserable. Parents should use whichever they think works best, but consider trying ibuprofen first if they aren’t sure. It’s the same as in adults; most people know after trial and error which medicine works best for them.

Why Not Aspirin?

Doctors don’t recommend aspirin for children due to the rare but serious risk of Reyes syndrome.

Don’t forget that ibuprofen is generally very safe but can cause heartburn symptoms if used many times, or for many days (same problem as in adults). Tylenol does not have that stomach problem; large overdoses can cause liver problems.

Do You Even Need To Treat A Fever?

An important point for parents, especially nervous first timers, is that you do not need to treat your child’s low-grade fever. For a typical common cold low fever, anti-fever medicine certainly isn’t directly killing the virus, and it doesn’t speed up healing the infection; it’s only for comfort. There is data to suggest that a light fever (under 40 Celsius, 104 Fahrenheit) is an effective germ fighter, and taking anti-fever medicine (especially ibuprofen) may slightly inhibit that natural healing process. On the other hand, no good studies show that taking anti-fever medicines will prolong a common cold. So, if your child seems otherwise well and isn’t too irritable, you don’t have to constantly monitor your child’s temperature and automatically give medicine every time their temp is over 38 Celsius/100.4 Fahrenheit. It’s much more important to keep up a healthy diet, to rest and stay hydrated.

A higher fever is a different story; the body’s immune system starts to deteriorate at temperatures over 40 Celsius/104 Fahrenheit. At those temps, you should definitely use fever medicines. You don’t have to obsess over brining it down 100% to normal; a few degrees is usually beneficial. This may be the time to use both medicines at the same time. Also, at this high temperature, you need to be evaluated by a doctor.

By the way, you should not avoid these pain/fever medicines for any condition just because you’re coming in to see your doctor because you think they may diagnose it better; a good doctor can diagnose anything even while you’re taking pain/fever medicine; so, please, there’s no need to suffer — take your pill!

Where To Buy

These are both generic and OTC, available in all pharmacies. You can find on Amazon here with links for ibuprofen for kids as well as acetaminophen for kids.

Read More

I have a collection of articles about children and health. Also, more health advice at my YouTube channel, including this video about Sudafed vs Afrin for a runny nose:

(This post was updated October 2024)