Melatonin won't cure your sleep problems — and it might even be harmful

Getting a good night’s sleep during the pandemic has been no easy task.

Anxiety, disrupted schedules, less physical activity, and more screen time are just a few common reasons why sleep has been hard to come by the last two years.

It’s no coincidence then that sales of the over-the-counter sleep aid melatonin have spiked dramatically. Nielsen reports that in 2020, Americans spent $826 million on melatonin supplements, a 43 percent increase from the year before.

This surge has doctors concerned. For one, melatonin supplements aren’t regulated by the Food and Drug Administration (FDA), so there are no guarantees that what the label says is inside the pills actually is.

“This is the only hormone [supplement] that’s not FDA approved,” Jamie Zeitzer, an Associate Professor of Psychiatry and Behavioral Health at Stanford University tells Inverse. Zeitzer is a circadian physiologist specializing in the understanding of the impact of light on circadian rhythms.

“We all need to reduce anxiety and prioritize sleep,” Whitney Roban, a clinical psychologist and sleep specialist tells Inverse. “There are so many ways to achieve that without reaching for a pill and so many reasons reaching for a pill isn’t the most effective solution.”

What is melatonin?

Melatonin is a hormone our body naturally produces during the sleep/wake cycle, or what researchers call the circadian rhythm. As it becomes darker the pineal gland secretes melatonin. The precise molecular mechanism by which melatonin affects sleep isn’t clear, but, synthetic melatonin is often effectively used to treat insomnia and jet lag. In the United States, synthetic melatonin is available over the counter; in the U.K., melatonin is only available by prescription and only for short-term sleep problems (prescribed for up to 13 weeks). It’s also typically prescribed in small doses (2 mg); in the United States, over-the-counter melatonin supplements can be found in doses as high as 20 mg.

While Zeitzer doesn’t believe a prescription is necessary to take melatonin, he does wish it was regulated by the FDA, much the way Tylenol or other over-the-counter medications are. He also thinks people should be very cautious when giving it to their children and especially — as it’s often used — by kids who have developmental delays because it hasn’t been studied extensively in that population.

The problem with melatonin supplements

Again, what’s on the label of any given supplement, including melatonin, doesn’t always match what’s in the pill. Supplements aren’t regulated by the FDA and thus quality and ingredients can vary widely.

In fact, recent studies have found that the amount of melatonin in these supplements doesn’t always reflect what the bottle says, and there can be other, potentially harmful, non-disclosed ingredients to boot. A 2017 study published in the Journal of Clinical Sleep Medicine found that the amount of melatonin in various over-the-counter supplements could range from as much as minus 83 percent to more than 478 percent of what’s on the label. 70 percent of the products tested were found to have melatonin concentrations less than or equal to 10 percent of what was claimed. Making matters worse, the authors write, “the content of melatonin between lots of the same product varied by as much as 465 percent.”

They also found that these supplements often included active ingredients not listed on the label like valerian and serotonin. While some of these may be the result of poor quality control or other herbal ingredients in the supplements, others might be the result of melatonin degradation, the reachers write, and for many the source of the serotonin contaminant is unknown.

“So many people are on drugs like SSRIs [Selective Serotonin Reuptake Inhibitors] and other drugs that might have contraindications with some of these ingredients. Most people do not check in with their doctor before taking melatonin supplements, which can be quite dangerous,” Roban says.

Because it’s a hormone naturally produced by the body, melatonin supplements are often touted as “non-sedating and non-addictive,” both of which are typically true. Those terms often imply a level of general safety, however, that is simply not borne out by science.

Researchers haven’t fully tested the effects of taking melatonin in high doses nor have they tested it over an extended period of time, Roban says. Higher doses (above 5 mg) are also more likely to result in negative side effects, a 2018 study found.

The negative side effects of melatonin

Negative side effects are a real concern considering how many over-the-counter products—both according to the label and confirmed via independent testing—have more than 5 milligrams​​.

“If you go into your local drugstore, most melatonin products are 5 to10 milligrams,” Roban says. “Anything over 5 milligrams has been shown to increase the likelihood of negative side effects like nausea, increased anxiety, and headaches. The side effects I hear about the most are very vivid dreams and nightmares.”

While the precise mechanism by which melatonin can cause vivid dreams and nightmares isn’t known, some sleep doctors have hypothesized that melatonin may extend REM sleep—the cycle of sleep in which dreams occur—increasing the likelihood one has vivid or nightmarish dreams.

This can be particularly troublesome when parents want to treat their children’s sleeplessness with melatonin, Roban says, something she sees regularly and typically advises against.

“I don't recommend parents give it to their kids, especially young kids who might not tell you the next day that they're not feeling well. Even if you know they’re not feeling well, you might not associate it with melatonin. But it could be that they're taking too much for too long. And they could be having nightmares or feeling anxious or nauseous because of the melatonin.”

There are other reasons to keep any melatonin use short term, Roban says.

“For some people, it might work temporarily, but it's not meant to be used long term. What’s going to happen is your sleep issues are going to come back because you’re not getting to the root of the problem,” she says.

What’s more: the payoff from melatonin isn’t as dramatic as you might think. A meta-analysis of 17 studies “showed melatonin shortened sleep latency by a mean of 4 min, increased sleep efficiency by 2.2 percent and lengthened sleep duration by 12.8 min; all values are modest at best.”

How to get better sleep—without taking melatonin

While melatonin can feel like an easy bandaid, there are alternative, perhaps more sustainable ways to get a proper night’s rest. The number one cause of behavioral sleep problems is stress and anxiety, Roban explains. To address those, she recommends trying to calm the body as well as the mind.

“We all need tools for lower anxiety and I always say the tools I teach for sleep can also be used whenever you feel anxious,” she says. “Things like journaling and meditation are great ways to calm the mind before bed.”

Just as important is what you don’t do before trying to fall asleep. Watching an exciting or intense show, exercising, and staring at your phone or computer all make the list of what not to do before bed.

If, for some reason, you have to be on your phone or staring at a screen before bed, wearing blue light glasses may help offset some of the anti-melatonin stimulating effects of that light, Roban adds.

Zeitzer says some of the marketing around blue light glasses has overstated their capabilities: When you’re binging a thriller on Nextflix, the blue light isn’t the only thing keeping you up, it’s the whole stimulating scenario. But, he says, some blue light glasses do block that particular kind of light and putting them on can be a reminder to yourself that it’s close to bedtime and time to wind down.

Calming routines can also be a signal to your brain that it’s time to wind down and help relax your body.

“It sounds obvious but when we’re not doing things that promote relaxation and sleep, it’s going to be harder for us to relax and sleep,” Roban says. “Having a sleep-promoting drink like warm milk or chamomile tea while you’re trying to wind down for sleep is a great pre-bedtime routine.”

Not only will the routine mentally signal to your brain that it’s time to wind down, but warm milk is also thought to stimulate the effects of tryptophan in the brain. Similarly, chamomile is believed to have flavonoids that may interact with benzodiazepine receptors in the brain, which are also involved with circadian rhythm.

Roban frequently works with both teenagers and adults who have sleeping problems and says a common theme among both age groups is anxiety over not being able to fall asleep. That can spur a vicious cycle.

Giving yourself permission to have a bad night’s sleep can actually help you have a good one.

“I talk a lot about sleep drive,” she says. “If you don't sleep well for a night or two, your body's physically going to crave that sleep. So if you can just tell yourself that you might not sleep well that night but the next night you will be even more tired and it will be easier for you to get it.”

Roban says she isn’t opposed to the idea of sleep aids, it’s just we don’t have one that’s been proven to be completely safe and effective long-term. Until there is, she says, “We just need to prioritize sleep. And the good news is there are very simple and straightforward ways to do that.”