Each dose (one 30 mL dose cup) contains 50 mg.
ZzzQuil Nighttime Sleep Aid Liquid, Cherry, 12 FL oz - 12 oz | CVS ZzzQuil Calming Vanilla Cherry tastes great - you'll look forward to falling asleep whether you are at home or traveling through multiple time-zones.ZzzQuil is the World's #1 Sleep Aid Brand! It contains a non-habit-forming ingredient, Diphenhydramine HCI, which causes drowsiness by blocking the action of histamine, a chemical that sends waking signals to the brain.