What to Know Before You Take It

First Published 2017 / Updated March 2021

Sales of melatonin supplements skyrocketed by more than 40% from 2019 to 2020 due to the rise in sleeplessness during the COVID-19 pandemic. But do they really work?

A Natural Hormone

Melatonin is a natural hormone produced by the pineal gland in your brain that regulates your body's sleep-wake cycles. These are the natural near 24-hour biological cycles often referred to as circadian rhythm.

This hormone is only secreted at night, in dim light or darkness, to signal to your brain and body that it is time to go to sleep. "Melatonin is the body's biological 'dark signal' that helps promote sleep," says Phyllis C. Zee, MD, PhD, chief of sleep medicine in the Department of Neurology at Northwestern Medicine.

However, melatonin is not helpful in fixing all types of sleep issues. "In most cases, taking a melatonin supplement might not necessarily be the answer to sleep troubles," states Ian S. Katznelson, MD, neurologist at Northwestern Medicine Lake Forest Hospital.

Not for Everyone

"Melatonin supplements are generally not recommended for the treatment of insomnia disorder," advises Dr. Zee. To date, there is not enough evidence on how effective it is in patients with chronic insomnia. However, there is some evidence that melatonin may be beneficial in increasing sleep time in some older adults.  Certain patients — pregnant women and children, and those with diabetes, high blood pressure or epilepsy — should consult their health care professional before taking melatonin supplements.

"People also may have different effects when taking melatonin supplements, depending on their ability to metabolize the drug, the inconsistency of the amount in each tablet and added ingredients in the various formulations," states Dr. Zee. "It's very important to look at the label carefully when taking melatonin."

Dose and Timing Matters

Although melatonin is generally safe and not likely to cause dependence, how much you take and when you take it can alter its effect.

It's best to start by taking the lowest effective dose, which is typically between 0.5 and 1 milligrams. This still creates a level of melatonin that is generally higher to what your brain makes naturally to maintain a normal sleep-wake cycle. "Too much melatonin can make you feel groggy and tired the next day," advises Dr. Katznelson.

When melatonin supplements are taken is important. For example, for the management of delayed sleep wake phase disorder, a sleep specialist may recommend low dose melatonin to be taken several hours before the natural sleep time, whereas for other types of sleep disturbances, it may be taken closer to bedtime.  There is not enough research to determine the safety and risk of side effects from the long-term use of melatonin.  

Other Options for Sleep Support

Lifestyle changes could also improve your sleep by controlling your natural levels of melatonin. Help protect your circadian rhythm by limiting your screen time an hour or two before bed, maintaining a bedtime routine and increasing your exposure to daylight.

Exposure to bright light at night can block melatonin production. "Get bright light during the day, even via an indoor artificial source, and decrease light exposure in the evening to enhance natural melatonin levels," recommends Dr. Zee.

Additionally, review your list of prescription medications. Medications such as beta blockers and antidepressants can inhibit or interact poorly with melatonin. Everyone should consult their healthcare provider or sleep specialist before taking melatonin.