Compare Benadryl vs. ZzzQuil

Diphenhydramine, also known by the brand name Benadryl, is an over-the-counter antihistamine used to relieve allergy or common cold symptoms in adults and children. It comes as pills and a liquid and is typically taken by mouth every 4 to 6 hours as needed. Because it can make you drowsy, some people also use it as a sleep aid at bedtime. Common side effects include sleepiness, dizziness, and dry mouth.