For many 6-year-olds, diphenhydramine is 12.5–25 mg every 4–6 hours, with a daily limit set on the package.

A common diphenhydramine dose is 1 mg per pound, so a 65-lb dog often gets 65 mg per dose.

A 60-lb dog is often dosed at 50–100 mg of plain diphenhydramine per dose, spaced 8–12 hours apart, only when your vet says it fits your dog.

Most dogs land near 1 mg of diphenhydramine per pound, so a 55-lb dog often starts around 25 mg per dose, given 2–3 times daily with vet approval.

A typical diphenhydramine dose for a 50-lb dog is 50 mg per dose, given every 8–12 hours only when a vet says it fits.

A 5-lb dog can be harmed by Benadryl without a vet’s exact dose, so call your clinic before giving any.

Diphenhydramine dosing for a 4-year-old depends on weight and product strength, and many labels say to ask a clinician before use under age 6.

A 25-lb dog often lines up with 25 mg diphenhydramine per dose every 8–12 hours, only when your vet says it fits.

Most adults take 25–50 mg of diphenhydramine per dose, spaced 4–6 hours apart, while staying within the daily limit on the label.

Many adult Benadryl labels allow 25–50 mg per dose each 4–6 hours, with no more than 6 doses in 24 hours.