The following table gives diphenhydramine dosing guidelines by weight. It can be used for the different products available, including Benadryl, generics and store brands. Benadryl can be given every six hours.

Diphenhydramine is a very effective medicine for allergic reactions, nasal allergies and hives in children over 2 years of age.  Please consult with our office for children under 2 years.

Always use  the dropper or teaspoon provided with the medication.

The most common side effect of diphenhydramine is drowsiness and occasionally excitation instead.  Do not drive or operate heavy machinery after taking a dose of medication.

If your child has concerning symptoms and you would like them seen in the office, you can book a same day sick (week days) or urgent care visit (weekends/holidays) using MyChart.

Source: adapted from


WeightDoseLiquid 12.5 mg/5ml(tspLiquid 12.5 mg/5ml(tsp)Chewable 12.5 mgTablets 25 mg Capsules 25 mg
20-24 lbs9.3 mg3/4 tsp4 ml---
24-37 lbs12.5 mg1 tsp5 ml1--
38-49 lbs18.75 mg1 1/2 tsp7.5 ml 1 1/21/2-
50-99 lbs25 mg2 tsp10 ml2 11
100+ lbs50 mg--422