Glossary

melatonin

Melatonin is a hormone your body makes to help you sleep. It tells your body when it’s time to go to sleep and when it’s time to wake up. You make more melatonin when it’s dark outside and less when it’s light. You also make less melatonin as you get older. Doctors may recommend slow-release melatonin supplements to treat excessive daytime sleepiness (EDS) and severe sleep inertia.