A person sleeping in a bed

Sleep troubles have long been a common complaint for Americans—and the stresses of the COVID-19 pandemic seem to have wreaked further havoc on our ability to get a good night’s rest.

Fifty-six percent of Americans say they’ve experienced an increase in sleep disturbances since the start of the COVID-19 pandemic, most commonly reporting trouble staying or falling asleep, according to an April 2021 survey (PDF) of more than 2,000 people by the American Academy of Sleep Medicine (AASM). And we hadn’t been resting easy before. In 2018, 80 percent of adults in the U.S. said they struggled with sleep at least once a week, according to a nationally representative Consumer Reports survey of 1,767 adults.

In searching for relief, many turn to dietary supplements. Just over half of Americans say they’ve used supplements, medications, or other substances to help them fall asleep, according to the AASM, with 68 percent saying they used sleep aids more frequently than before.

The most popular supplement for sleep, by far, is melatonin, a hormone naturally produced by the body that governs our sleep-wake cycle. In 2020 melatonin sales grew a staggering 42.5 percent, to $687 million, according to Nutrition Business Journal, perhaps driven just not by the desire for more shut-eye but also by reports suggesting it may help protect against COVID-19.

Is that money well spent? 

More on Sleep

Melatonin's value as a COVID-19 preventative is still unclear. One study found it was associated with a 28 percent reduced risk of testing positive for the virus, and other preliminary research suggests it may help people with severe COVID-19 symptoms. But more evidence is needed before it can definitively be said that the hormone has these effects, the National Institutes of Health says.

As for sleep, the scientific research is mixed, says Charles Czeisler, PhD, MD, chief of the division of sleep and circadian disorders at Brigham and Women’s Hospital in Boston. “Melatonin has important but limited uses,” he says.

Melatonin is a hormone secreted by the brain’s pineal gland, usually at night. It regulates the body’s circadian rhythm, the approximately 24-hour internal “clock” that helps control when you’re sleepy and when you feel awake.

It’s the “hormone of darkness,” Czeisler says, something that the brain should start to release as it gets dark, a few hours before we usually go to sleep.

Taking a synthetic supplemental form of that hormone might help people who aren’t producing the hormone naturally because of age, one of several health disorders, or because they’re trying to go to bed at a different time than usual. But it’s less likely to help in most other circumstances and could cause side effects like next-day drowsiness.

Here’s what to know about melatonin, including when it might help and how to take it safely.

When Melatonin Can and Can't Help

Some people with certain kinds of sleep disorders may get some relief from melatonin, research suggests, but there’s less evidence for its use with more common forms of insomnia, according to the NIH’s National Center for Complementary and Integrative Health.

A 2013 meta-analysis found that on average, people with insomnia fell asleep about 7 minutes faster with melatonin than with a placebo. While most melatonin side effects are mild, CR’s survey showed that people may be taking it in unsafe ways, for example, driving too soon after taking it or taking it long term (for years) when there’s little data indicating that longer than three months is safe.

Because of the lack of evidence, the American Academy of Sleep Medicine recommends clinicians not use melatonin as a treatment for insomnia.

But that doesn’t mean it can’t help anyone.

About 5 to 10 percent of people may feel sleepy after taking melatonin, says Alcibiades Rodriguez, MD, the medical director of the Comprehensive Epilepsy Center-Sleep Center at New York University.

“Usually the people that get more benefit are the elderly, maybe 70 or older, and young patients,” he says. That’s because older patients and young children are less likely to produce sufficient melatonin on their own, though it’s important to consult a medical professional before giving a child melatonin. There’s still little research on melatonin in kids and some concern about how it might affect development, especially around puberty

Because the general cue for the body to start releasing melatonin is the change from daylight to darkness, supplements may be essential for people with circadian disorders related to blindness, Czeisler says. It can also help people who need to fall asleep at a time that’s not in sync with their natural clock, like people working a night shift or anyone experiencing jet lag because they have traveled to a new time zone.

Czeisler says melatonin may help some extreme night owls—people whose internal clock makes them inclined to fall asleep hours later than would be considered reasonable—by helping to get their body clocks on a more normal schedule.

What to Know Before You Take Melatonin

  • Start small and don’t overdo it. Many stores sell supplements that are packed with far more melatonin than the body naturally produces. Czeisler recommends starting with a low dose, between 0.2 and 0.5 mg. The Council for Responsible Nutrition, a supplement trade group, says doses should not exceed 10 mg, even though products with higher doses are available.
  • Get it from a safe source. Supplements aren’t subject to the same standards set by the Food and Drug Administration for safety and efficacy as are over-the-counter and prescription drugs. That means supplement makers don’t have to show that their products work. Certain supplements may contain a higher or lower dose or may have other potentially dangerous ingredients. Labels from the supplement-verifying organizations ConsumerLab.com, NSF International, USP, and UL can provide some assurance that a product contains what's listed on its label and that the product isn’t contaminated with something risky.
  • Make sure it won’t interact dangerously with other drugs you take. Melatonin can change the way other drugs work, making blood pressure and diabetes drugs less effective and increasing the effects of blood-thinning drugs, for example. Talk to your doctor before taking melatonin if you take any medication.
  • Be careful driving the next morning. Short-term use of melatonin is generally considered safe, Rodriguez says. But some people do report drowsiness, headaches, dizziness, or nausea. The Council for Responsible Nutrition says not to drive while using melatonin. 
  • Be cautious about long-term use. Studies have shown that melatonin appears to be safe when used for three months or less, according to reviews of research and the NIH. But a lack of long-term studies means we don’t know if long-term use is safe. 
  • Talk to a doctor about sleep problems. Whether melatonin helps you, you should consult your doctor if you’ve had trouble sleeping for three months or longer, according to Rodriguez. “The longer insomnia goes, the more difficult it is to treat,” he says.

Editor's Note: This article has been updated since a version first appeared in the February 2016 issue of Consumer Reports magazine.