Adults can take Motrin (ibuprofen) every four to six hours as needed for pain, with a maximum of 1,200 mg per day when using it over the counter. For children, the same four-to-six-hour interval applies, but the dose is based on weight. Each dose typically provides relief for four to six hours, with effects kicking in within 30 to 60 minutes.
Adult Dosing Schedule
The standard adult dose of Motrin is 200 to 400 mg every four to six hours. Most over-the-counter tablets come in 200 mg, so that means one to two tablets per dose. For menstrual cramps specifically, 400 mg every four hours tends to work better than smaller doses spaced further apart.
The over-the-counter ceiling is 1,200 mg in 24 hours, which works out to three doses of 400 mg. Prescription doses can go higher, up to 3,200 mg per day for conditions like rheumatoid arthritis, but that range is only appropriate under medical supervision. Stick with the lowest effective dose for the shortest time you need it.
How Often to Give Motrin to Children
Children can take Motrin every six to eight hours as needed. The dose is calculated by weight, not age, which is why the packaging includes weight ranges. As a general rule, the dose is about 5 to 10 mg per kilogram of body weight per dose.
One critical detail that trips parents up: infant drops and children’s liquid are different concentrations. Infant drops contain 50 mg per 1.25 mL, making them twice as concentrated as children’s liquid, which contains 100 mg per 5 mL. Using the wrong measuring tool or swapping one product for the other can lead to giving half or double the intended dose. Always use the syringe or cup that comes in the box, and check the concentration on the label before measuring.
Motrin is not recommended for babies under 6 months old. For infants between 6 and 11 months, dosing should be confirmed with a pediatrician, especially for the first use.
How Long Each Dose Lasts
Ibuprofen starts working within 30 to 60 minutes and provides pain relief for four to six hours. If you find that relief fades closer to the four-hour mark, it’s fine to take the next dose at that point rather than waiting the full six hours, as long as you stay within the daily maximum. If pain consistently returns before four hours, that’s a sign the dose may not be adequate or ibuprofen may not be the right fit for what you’re dealing with.
Don’t Use It Indefinitely
Over-the-counter Motrin is meant for short-term use. The general guideline is no more than 10 consecutive days for pain and no more than 3 consecutive days for fever. If you’re still reaching for it after those windows, something else may be going on that needs attention.
Even within those limits, taking the smallest dose that controls your symptoms is the safest approach. Ibuprofen can irritate the stomach lining, affect kidney function over time, and increase cardiovascular risk. That risk exists for people with and without heart disease, though it’s greater for those who already have it. If you take aspirin for heart protection, be aware that ibuprofen can interfere with aspirin’s ability to prevent clots.
Alternating Motrin With Tylenol
When one medication alone isn’t controlling pain or fever well enough, alternating Motrin with acetaminophen (Tylenol) is a common strategy. The key rule: don’t take both at the same time. Take one first, then switch to the other four to six hours later. You can continue alternating every three to four hours throughout the day.
This works because the two drugs reduce pain through different mechanisms, so staggering them keeps a more consistent level of relief without exceeding the safe limit of either one. It’s especially popular for managing children’s fevers, though you should confirm the correct dose for each medication with your child’s pediatrician based on their weight.
A practical tip from the Cleveland Clinic: write down which medication you gave and the exact time. When you’re alternating two drugs every few hours, especially in the middle of the night with a sick child, it’s easy to lose track. Taking either medication with a small amount of food, even just a few crackers or a banana, helps reduce stomach irritation.
If you find yourself alternating the two for more than three days, that’s worth a conversation with a healthcare provider rather than continuing on your own.
When to Space Doses Differently
Certain situations call for a longer interval between doses or a lower daily total. People with a history of stomach ulcers, kidney problems, or heart disease should use ibuprofen sparingly if at all. The same applies to anyone taking blood thinners or blood pressure medications, since ibuprofen can reduce the effectiveness of some of those drugs and increase bleeding risk with others.
Older adults are more susceptible to ibuprofen’s side effects on the stomach and kidneys, so spacing doses further apart and keeping the total daily amount low is a reasonable precaution. If you’re over 60 or on multiple medications, a pharmacist can help you figure out whether ibuprofen fits safely into your routine and at what frequency.