Both work, both are safe dosed by weight: acetaminophen every 4 to 6 hours from birth, gentler on the stomach; ibuprofen every 6 to 8 hours from 3 months, lasting a bit longer - but avoid ibuprofen in a dehydrated child.
The NHS says give either for a distressed, uncomfortable child - you treat the misery, not the number. On alternating doses: thin evidence, double the dosing-error risk, and guidance discourages it - pick one and dose it right. The error that actually hurts kids is measuring: dose by current weight with the syringe in the box, per the FDA - a kitchen spoon is not a measuring device.
What to do
Common questions
Tylenol vs Motrin for a kid's fever?
Both are effective, both are safe when dosed by weight, and the honest answer is that for most fevers they perform similarly - the differences are in timing and the fine print. Acetaminophen (Tylenol, acetaminophen): usable from birth, dosed every 4 to 6 hours, gentler on the stomach, and the default first choice for young babies. Ibuprofen (Motrin, Advil): from 3 months up per labeling, every 6 to 8 hours, lasts a bit longer per dose, and anti-inflammatory - but avoid it in a dehydrated child (kidney caution) and in varicella (chickenpox). The NHS's own fever guidance says give either if the child is distressed or uncomfortable - treating the misery, not the number. On the alternating-doses strategy parents trade online: the evidence for combining is thin, the schedule doubles the chance of a dosing error, and guidance bodies discourage routine alternating - pick one, dose it right. The error that actually hurts kids is dosing: always by current weight, always with the syringe or cup in the box - per the FDA, a kitchen spoon is not a measuring device. Pymander, a free AI doctor available 24/7 by text, can help you calculate the right dose.