Melatonin 

Melatonin is a hormone made by the pineal gland. That’s a pea-sized gland found just above the middle of your brain. It helps your body know when it’s time to sleep and wake up.

Normally, your body makes more melatonin at night. Levels usually start to go up in the evening once the sun sets. They drop in the morning when the sun goes up. The amount of light you get each day — plus your own body clock — set how much your body makes.

You can also buy melatonin supplements. They come in pills, liquids, and chewables. You might find them in natural or synthetic forms. The natural forms are made from the pineal gland in animals.

Why Take It?
People use melatonin when they have insomnia — trouble falling asleep and staying asleep. They also take it for other sleep problems. This could include something called delayed sleep phase disorder. If you have that, falling asleep before 2 a.m. is tough. So is getting up in the morning.

Folks may also try it if they have jobs that disrupt typical sleep schedules, a condition called sleep work disorder.

It’s used to treat or prevent jet lag, too. That’s the tired, run-down feeling some get when they’re traveling across time zones.

Doctors are also studying to see if melatonin can help with:

Alzheimer’s disease
Cancer
Amyotrophic lateral sclerosis (ALS)
High nighttime blood pressure
Sleep problems in children with autism spectrum disorders
Is It Safe?
While melatonin generally brings fewer side effects than other sleep medicines, you could still have:

Daytime sleepiness
Headache
Dizziness
Stomach discomfort
Anxiety
Crankiness
A “heavy head” feeling
Short-lived depression
Melatonin supplements might cause problems if you take them with some medicines, including:

Blood-thinning medications (anticoagulants)
Drugs that suppress the immune system (immunosuppressants)
Diabetes drugs
Birth control pills
Tell your doctor if you’re thinking about taking any supplement, especially if you take any medicine or have a health condition.

The natural form of melatonin might have a virus or other issues. If you take melatonin, pick a synthetic type.

How Well Does It Work?
Everybody reacts differently to medicines and supplements, so melatonin may or may not work for you.

Some studies say it could help with jet lag and some sleep issues like delayed sleep phase disorder, shift work disorder, and some sleep disorders with children.

Other research shows it may let people with insomnia fall asleep slightly faster. It may also help you sleep better through the night, but not necessarily longer.

Still more studies have shown that melatonin doesn’t help sleep problems at all. There’s also not enough research to say it helps with any issues not related to sleep.