When you're having trouble getting that sound sleep your body craves, add some Zzzs to your night with ZzzQuil. ZzzQuil liquid capsules work to help you fall asleep fast - in as little as 20 minutes - so you can get the sleep when you need it and wake refreshed. All ZzzQuil products are non-habit forming and specifically formulated with clinically proven ingredients by our team of dedicated scientists. They contain 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. Each dose (2 LiquiCaps) contains 50mg. It helps you get some shut-eye, so you can wake up feeling refreshed and ready to take on your day.