Tylenol or Motrin for Infant Fever? Age Changes the Answer

For infant fever, the right choice depends on your baby's age. At 3 months or younger, call your pediatrician before giving any fever medicine. A baby under 12 weeks should be seen first. Over 3 months and up to 6 months, Tylenol (acetaminophen) is the only over-the-counter option, and only after you check with your pediatrician. After 6 months, either one can work with your pediatrician's OK, but Motrin has label conditions about fluids.

Each of those lines is written down somewhere specific. For a fever under 12 weeks, the AAP's symptom guide says: "do NOT give your baby any fever medicine before being seen." The Infants' Motrin label prints "under 6 mos" next to "ask a doctor." And the Infants' Tylenol label gives no dose for babies. Its chart row for "under 2 years" says "ask a doctor."

This article provides general information about medication management and is not a substitute for professional medical advice. Always consult your pediatrician or pharmacist before giving your baby any medicine. Consult your doctor or pharmacist for advice specific to your medications.

Tylenol or Motrin for Infant Fever by Age

The right-hand column comes from the AAP symptom guide, except where HealthyChildren is named. The same guide also lists a fever that "lasts more than 3 days" or "returns after being gone for more than 24 hours" as reasons to contact the doctor within 24 hours. For Tylenol, the AAP's parent site says to "always call your pediatrician before giving acetaminophen to a child under 2 years of age."

Temperature lines after 3 months differ by source. HealthyChildren says you may need to notify the doctor at 101°F (38.3°C) or higher between 3 and 6 months. After 6 months, its line is 103°F (39.4°C). MedlinePlus says to contact the provider right away for a baby 3 to 12 months old at 102.2°F (39°C) or higher. How long a fever lasts also counts, and the sources differ here too. The AAP guide uses more than 48 hours for a baby 6 to 12 months old with no other symptoms. MedlinePlus says to contact the provider right away if a child 2 years or younger has a fever that lasts longer than 24 to 48 hours. Ask your pediatrician which line to use.

Can a Newborn or 2 Month Old Have Tylenol for Fever?

Is your baby 3 months or younger, with a rectal temperature of 100.4°F (38°C) or higher? HealthyChildren says to call your pediatrician immediately. The AAP guide lists "Fever in baby less than 12 weeks old" under "Call Doctor or Seek Care Now." The AAP symptom guide is blunt about why: "Fever that occurs during the first 3 months of life can be serious. All of these babies need to be seen as soon as possible."

A 2021 review summary in American Family Physician states the AAP position. The AAP "recommends against the use of acetaminophen in infants younger than three months or ibuprofen in those younger than six months without clinical evaluation."

Can a 3 or 4 Month Old Have Tylenol or Motrin?

Between 3 and 6 months, Motrin is still not something to give on your own. The Infants' Motrin label covers ages 6 to 23 months and says "ask a doctor" for anything younger.

Tylenol is the medicine the AAP symptom guide names for fever. It lists ibuprofen only "if over 6 months old." You still need your pediatrician's go-ahead and the amount to give, because the Tylenol label gives no dose for babies. The same guide lists "Age 3-6 months old with fever" as a reason to contact the doctor within 24 hours.

The same guide also says "fever meds are not needed" for fevers of 100° to 102° F. On fluids, it says: "Until 6 months old, only give extra formula or breastmilk."

Why Can't Babies Have Motrin Before 6 Months?

It is easy to read the 6-month line as proof of harm. A 2018 study in PLOS ONE notes that "many US prescribers interpret lack of OTC labeling as meaning that ibuprofen is unsafe for infants younger than six months." The record says something narrower.

Start with the trials. The prescription ibuprofen suspension label says its fever studies were done "in children 6 months to 12 years of age." Below 6 months, safety and effectiveness "have not been established."

The same PLOS ONE study describes a 1999 request to the FDA for over-the-counter labeling under 6 months. It "was rejected as having too few infants (n = 319) in this age group."

Newer evidence did not fill the gap. A 2020 meta-analysis in JAMA Network Open found that only 2 randomized studies included infants under 6 months, and neither gave usable data for that group.

"Not established" is not the same as "safe," though. The PLOS ONE study used California Medicaid records. Stomach side effects were about a quarter more common in babies under 6 months prescribed ibuprofen than in those prescribed acetaminophen alone. Most babies prescribed ibuprofen had also been prescribed acetaminophen, so the comparison is mostly babies prescribed both against babies prescribed acetaminophen alone. The same study did not find more side effects in babies first prescribed ibuprofen before 6 months than in those first prescribed it after 6 months.

The JAMA review notes that several authors caution against ibuprofen in younger infants. Their concern is kidney injury, "particularly in the context of dehydration." The review's own pooled data did not show that risk. But the authors did not specifically study children at risk of dehydration, and they had no usable data on babies under 6 months. In the US, the label line stands, and the decision belongs to your pediatrician.

Is Motrin or Tylenol Better for Infant Fever After 6 Months?

On the numbers, ibuprofen comes out ahead, though the authors call it "weak evidence to support ibuprofen use over acetaminophen." The 2020 meta-analysis included 19 studies of children under 2 (241,138 participants in all). Ibuprofen was linked to lower temperatures than acetaminophen in the window up to 4 hours after a dose and from 4 to 24 hours. It was also linked to less pain from 4 to 24 hours. Serious side effects were similar.

The results were reported on a statistical scale, not in degrees you can read off a thermometer. The authors also wrote that the lack of pain data in the first 4 hours "weakens the clinical importance of these findings."

The AAP's 2011 clinical report on fever says there is "no substantial difference in the safety and effectiveness of acetaminophen and ibuprofen" for a generally healthy child. It says the goal is the child's comfort, not a normal temperature.

One thing that can tip the choice is on the Motrin label. It says to ask a doctor before use if the "child has not been drinking fluids" or "has lost a lot of fluid due to vomiting or diarrhea." A baby who is refusing bottles or keeps throwing up is that baby. If the dose itself came back up, see what to do when your child throws up medicine. The label also lists asthma and kidney disease as reasons to ask first.

For children past their first birthday, our guide to a toddler fever of 103 walks through the first six hours after a dose.

Is Infant Motrin Stronger Than Children's Motrin?

Yes. The word "Infants'" means different things on each brand's box.

• Infants' Tylenol is the same strength as Children's Tylenol. The box says "Same as Children's TYLENOL," and HealthyChildren notes that infant acetaminophen drops "are no longer available."
• Infants' Motrin is labeled "Concentrated." Its label lists a different strength from the Children's Motrin label, so the two cannot be swapped milliliter for milliliter.

In a 2023 measuring study in Pediatric Research, 116 volunteers measured both ibuprofen strengths. Errors were larger with the infant concentration, and 31% of all attempts were off by more than half.

The Infants' Motrin and Infants' Tylenol labels say to use only the enclosed syringe. The Children's Motrin label says to use only its enclosed dosing cup. HealthyChildren adds: "do not use a household teaspoon." If a mix-up does happen, here is what to do after a double dose of Motrin or a double dose of Tylenol.

Baby Fever Tylenol Not Working?

The AAP symptom guide says: "Most often, the fever meds lower the fever by 2° to 3° F (1 - 1.5° C). They do not bring it down to normal. It takes 1 or 2 hours to see the effect."

Other times the fever is not the whole story. The same guide flags these:

• Crying that will not stop. "Frequent crying in a child with fever is caused by pain until proven otherwise." The guide names "ear infections, kidney infections, sore throats and meningitis" as hidden causes, and lists "Nonstop crying or cries when touched or moved" under "Call Doctor or Seek Care Now."
• Teeth get blamed, but "Research shows that 'getting teeth' does not cause fevers."
• Signs of dehydration: "No urine in more than 8 hours, dark urine, very dry mouth and no tears." Call or seek care now.
• Emergency signs. Call 911 if your baby is not moving, cannot wake up, has severe trouble breathing, or has purple or blood-colored spots on the skin. Go to the ER now for a stiff neck, a swollen soft spot, a seizure with the fever, a baby who is hard to wake up, or a baby who is not alert when awake ("out of it").
• Call the doctor or seek care now for a fever higher than 104° F (40° C), shaking chills lasting more than 30 minutes, an arm or leg your baby won't move normally, trouble breathing that is not severe, great trouble swallowing fluids or spit, a weak immune system (the guide's examples include sickle cell disease and taking oral steroids), or a baby who looks or acts very sick.

If a doctor prescribes antibiotics, here is what to do if your child misses an antibiotic dose.

How Often Should I Check My Baby's Temperature With a Fever?

The AAP and MedlinePlus pages cited here do not set a checking schedule for babies, so ask your pediatrician. The AAP guide says fever medicine takes "1 or 2 hours to see the effect." A reading before a dose and one after that window shows whether it helped.

Note your baby's age in weeks or months first, since it decides which rules apply. Then write down:

• Temperature, the time, and where you took it (HealthyChildren calls rectal the most reliable for babies)
• The product name and the time you gave it. "Infants' Motrin" tells a nurse far more than "medicine."
• Feeds and wet diapers, since the AAP guide uses 8 hours without urine as a warning line
• How your baby is acting between doses. A baby who is hard to wake up or "out of it" when awake is not something to log. The AAP guide says to go to the ER now.

Can't remember if the last dose went in? Here is what to do when you are not sure you gave your child's dose.

How Pillo Helps

Pillo's Dependents Management lets you add your baby as a dependent with their own medication list, separate from yours. Log each dose as you give it and check the history before the next one, which answers "did I already give it?" in seconds.

When your pediatrician tells you the earliest time for the next dose, set a reminder for it. Pillo's persistent alarm keeps going until you respond, so a 3am reminder does not vanish after one sleepy swipe.

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Frequently Asked Questions

Can I give my baby Motrin 4 hours after Tylenol?

Ask your pediatrician first, because this is really a question about using both medicines. The AAP symptom guide says: "Do not use both acetaminophen and ibuprofen together. Reason: not needed and a risk of giving too much." The AAP's 2011 report says there is evidence that combining them is more effective than one alone, but that combined treatment "may be more complicated and contribute to the unsafe use of these drugs." For a baby under 6 months, Motrin is not an over-the-counter option.

Should I give my baby Tylenol or Motrin after shots?

Is your baby still under 12 weeks old at the 2-month shots? Then a fever afterward still falls under the AAP rule to be seen before any fever medicine. The AAP symptom guide says fever with most vaccines begins within 12 hours and lasts 2 to 3 days. MedlinePlus lists a recent immunization among the reasons to contact your child's provider right away about a fever. Ask at the visit what your pediatrician wants you to do if a fever shows up that night.

Is it Tylenol or Motrin for infant teething?

Don't blame the teeth for a fever. The AAP symptom guide says "getting teeth" does not cause fevers, so the age rules for fever still apply. For teething pain without a fever, ask your pediatrician which medicine, if any, fits your baby's age.

If you think your baby has taken too much of any medicine, call Poison Control at 1-800-222-1222.

This article is for informational purposes only and does not constitute medical advice. Always consult your pediatrician or pharmacist before giving your baby any medicine or making changes to their medication routine.

Sources

• AAP / HealthyChildren symptom checker, Fever (0-12 Months): https://www.healthychildren.org/English/tips-tools/symptom-checker/Pages/symptomviewer.aspx?symptom=Fever+%280-12+Months%29
• HealthyChildren, Fever and Your Baby: https://www.healthychildren.org/English/health-issues/conditions/fever/Pages/Fever-and-Your-Baby.aspx
• HealthyChildren, Fever and Pain Medicine: How Much to Give Your Child: https://www.healthychildren.org/English/safety-prevention/at-home/medication-safety/Pages/Fever-and-Pain-Medicines-How-Much-to-Give.aspx
• MedlinePlus, Fever: https://medlineplus.gov/ency/article/003090.htm
• DailyMed, Infants' Tylenol label: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=997b9551-c222-4a9c-8ba1-09a5f97495fa
• DailyMed, Infants' Motrin label: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=c2302bfe-b367-4867-b803-29f066a42dc7
• DailyMed, Children's Motrin label: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=f2609308-17bf-4bcb-84b2-d17f3fd35958
• DailyMed, Ibuprofen Oral Suspension (Rx) label: https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=998f2fcf-0b40-4304-929f-7f2fa42f66d0
• Tan E et al. JAMA Netw Open 2020;3(10):e2022398: https://pmc.ncbi.nlm.nih.gov/articles/PMC7599455/
• Long B, Gottlieb M. Am Fam Physician 2021;103(9): https://www.aafp.org/pubs/afp/issues/2021/0501/od1.html
• Walsh P et al. PLOS ONE 2018: https://doi.org/10.1371/journal.pone.0199493
• Sullivan JE, Farrar HC. Pediatrics 2011;127(3):580-7: https://pubmed.ncbi.nlm.nih.gov/21357332/
• Leibovitch ER et al. Pediatr Res 2023;94(3):1145-1150: https://doi.org/10.1038/s41390-023-02573-7