Does ZzzQuil work?

ZzzQuil works, according to Drugs.com; its active ingredient is diphenhydramine, which is an antihistamine used to treat cold and allergy symptoms such as sneezing, itching, watery eyes and runny nose. It is also helpful for skin rashes and hives. Diphenhydramine is useful in treating motion sickness and inducing sleep.

Drugs.com warns of possible side effects including dizziness; drowsiness; dry mouth, nose or throat; constipation; upset stomach; dry eyes; or daytime drowsiness or a hangover sensation after use at night. ZzzQuil is an over-the-counter medication, but WebMD warns it is not safe to use for children under the age of 6 without physician approval.