Children’s Motrin (ibuprofen) can be given every 6 hours as needed, with a maximum of 4 doses in 24 hours. That means you should wait at least 6 hours between each dose, even if your child’s fever returns or pain comes back sooner. This applies to all forms of children’s ibuprofen, whether liquid suspension, chewable tablets, or junior-strength tablets.
Dosing Interval and Daily Limit
The standard interval is every 6 hours, not every 4 hours. This is a common point of confusion because acetaminophen (Children’s Tylenol) can be given every 4 to 6 hours, and parents sometimes mix up the two schedules. With ibuprofen, 6 hours is the minimum gap between doses, and you should not exceed 4 doses in a 24-hour period.
If your child’s fever or discomfort returns before the 6-hour mark, you have a couple of options. You can wait it out with comfort measures like cool cloths and fluids. Or, if a pediatrician has recommended it, you can give a dose of acetaminophen in between ibuprofen doses (more on that below).
How Much to Give Per Dose
The right dose is based on your child’s weight, not their age. The general guideline is 4 to 10 mg per kilogram of body weight per dose. Most children’s liquid Motrin comes in a concentration of 100 mg per 5 mL (one teaspoon). Here’s what typical doses look like using that concentration:
- 24 to 35 lbs (ages 2 to 3): 5 mL (100 mg)
- 36 to 47 lbs (ages 4 to 5): 7.5 mL (150 mg)
- 48 to 59 lbs (ages 6 to 8): 10 mL (200 mg)
- 60 to 71 lbs (ages 9 to 10): 12.5 mL (250 mg)
Always use the measuring syringe or cup that comes with the product. Kitchen spoons are unreliable and can easily lead to over- or underdosing.
Minimum Age: 6 Months
Ibuprofen should not be given to babies younger than 6 months old. The FDA has not approved it for that age group because its safety has not been established in very young infants. For babies under 6 months who have a fever or pain, acetaminophen is the standard option. If your baby is under 6 months and you’re unsure what to give, call your pediatrician first.
Alternating With Acetaminophen
Some parents alternate Children’s Motrin with Children’s Tylenol to manage a stubborn fever. This approach can lower fever more effectively than either medication alone, but the American Academy of Pediatrics notes it also raises the risk of dosing errors and accidental overdose. For that reason, alternating is not routinely recommended unless a pediatrician specifically suggests it.
If your child’s doctor does recommend alternating, keep a written log of every dose. Record the medication name, the amount given, and the exact time. The intervals stay the same for each drug individually: acetaminophen every 4 to 6 hours (max 4 doses per day) and ibuprofen every 6 hours (max 4 doses per day). In practice, this means you might give ibuprofen, then acetaminophen 3 hours later, then ibuprofen again 3 hours after that, so each medication stays on its own 6-hour (or 4-hour) cycle.
One important rule: only use single-ingredient products. Multi-symptom cold or flu medicines often contain acetaminophen or ibuprofen as one of several active ingredients. Giving those alongside a standalone pain reliever can result in a double dose without you realizing it.
Keep Your Child Hydrated
Ibuprofen works by blocking the production of chemicals called prostaglandins, which drive inflammation, pain, and fever. The downside is that prostaglandins also help maintain blood flow to the kidneys. When a child is dehydrated, their kidneys are already under stress, and ibuprofen can tip the balance toward kidney problems. Reports of acute kidney injury in children taking ibuprofen while dehydrated have been documented by drug safety monitoring agencies.
This matters most when your child has a stomach bug with vomiting or diarrhea, or during hot weather when they’re losing fluids faster than usual. If your child can’t keep fluids down, acetaminophen is the safer choice for fever and pain because it doesn’t carry the same kidney risk. Once they’re drinking normally again, ibuprofen is fine to use.
When Ibuprofen Isn’t Working
Ibuprofen typically starts reducing fever within 30 to 60 minutes, and its effects last about 6 to 8 hours. If your child’s temperature drops even a degree or two, the medication is doing its job. The goal isn’t necessarily to bring fever back to a perfect 98.6°F. Fever itself is part of the body’s immune response, and a mild fever in a child who is drinking, playing, and otherwise acting normally doesn’t always need to be treated at all.
If fever persists beyond 2 to 3 days despite regular dosing, or if your child seems increasingly lethargic, refuses fluids, or develops new symptoms like a rash, stiff neck, or difficulty breathing, that warrants a call to their pediatrician. The issue at that point isn’t the dosing schedule; it’s whatever is causing the fever in the first place.