Do melatonin, CBD, magnesium, valerian and other sleep supplements really work?
By Ashley Abramson, Michele Lent Hirsch
Americans have a lot of trouble sleeping. Only 41% say they sleep well or very well, according to a nationally representative survey (PDF) conducted in October 2022 by Consumer Reports of 2,084 American adults. And nearly all Americans (91%) say they have experienced at least one sleep problem in the past year, according to the survey.
So it’s no wonder that so many people turn to supplements in search of a good night’s rest. Trying to sleep better is one of the 3 most common reasons people say they’ve taken a supplement, according to a nationally representative survey (PDF) conducted in the summer of 2022 by Consumer Reports of 3,070 American adults. Approximately 1 in 3 Americans say they have taken supplements to get better sleep.
Melatonin was by far the most mentioned sleep supplement in our survey. CBD and magnesium round out the top 3, but are much less popular. And other vitamins and supplements, such as valerian, iron, and vitamin D, have also sometimes been promoted as sleep aids. Here’s what the tests say about whether any of them actually work, plus what you could try instead.
Whenever you buy a supplement, you should look for a seal of security from a trusted third party. (More information on the safety of supplements).
Melatonin
Your body runs on an internal clock called a circadian rhythm. Melatonin, a natural hormone, helps signal your brain that it’s time to go to bed. That’s the idea behind using a melatonin supplement at bedtime.
Evidence suggests that taking melatonin can help you fall asleep about 7 minutes faster, on average, and studies show it’s helpful for people with prolonged flight disorder. [jet lag] or with a sleep disorder called delayed sleep phase syndrome. But to avoid interfering with the body’s natural production, high doses shouldn’t be taken long-term, says Selena Chan, DO, a psychiatrist and interim director of clinical programs at the Osher Center for Integrative Health at the University of California, San Francisco. (For more information on this popular supplement, see our articles on melatonin for adults and melatonin for children.)
CBD
Some people use this compound, a non-psychoactive derivative of hemp [cannabis] or marijuana, to relieve anxiety and promote sleep.
A 2017 article suggests that CBD may be a reasonable treatment for insomnia, but the scientists stated that this type of research is in its early stages, and more long-term studies are needed. As long as you have good sleep habits and don’t take other medications at the same time, Chan says CBD can be beneficial before bed. You just have to check with your doctor first.
And buy carefully. CR tests have found that some CBD gummies do not have the amount of CBD stated on the label.
Magnesium
The mineral magnesium can help reduce stress and relax the body before bed. Magnesium supplements can be taken as pills or powdered to add to drinks.
However, research in this field is scarce. Although some studies link magnesium to better sleep quality, it’s not clear if taking supplements helps with sleep disorders like insomnia and restless legs syndrome. (Be sure to avoid the types called magnesium oxide or citrate sleep aids because these forms are most commonly used as laxatives.)
Iron
Iron deficiency is closely linked to restless legs syndrome, a disorder characterized by uncomfortable sensations in the extremities and an uncontrollable urge to move them, which can interfere with sleep. Do you think this could be your problem? Consult your doctor before treating it on your own. Taking iron could hide a more serious problem.
Also, for people who don’t have a deficiency, supplementation could lead to iron overload, which can damage organs.
Vitamin D
There is increasing evidence that there is a link between low vitamin D levels and sleep problems.
A study of 89 adults with sleep disorders, published in 2018, found that when people whose vitamin D levels were low (but not deficient) took supplements regularly for 8 weeks, they said they fell asleep faster, slept longer and had better sleep quality than those who received a placebo.
But other research has found that, in certain populations, the supplements have no positive effect on sleep, or may worsen it. What can you do? Talk to your doctor about getting tested for vitamin D deficiency, and whether it’s worth taking supplements.
Valerian
This root has been used for centuries to treat insomnia. Additionally, several studies suggest that this supplement may help people fall asleep more quickly and wake up less frequently at night, although grogginess may occur the next day. But other studies show no benefit.
Such mixed results may be due to the variable quality and instability of the active ingredients in valerian, according to a 2020 research review, so be sure to check the bottle for a trusted seal.
what else can you try
A consistent sleep routine can help signal to your body that it’s time for bed. Relax and put the screens aside. You could write a journal, read or take a bath, Chan says. Try to limit your alcohol intake, and don’t have caffeine after mealtime. For sleep disorders, medication or a form of psychotherapy called cognitive behavioral therapy for insomnia (CBT-I) may also be effective.
For more information on healthy sleep, check out CR’s Guide to Better Sleep.
Editor’s Note: This article has been adapted from material published in the February 2022 and January 2023 issues of Consumer Reports magazine.
Consumer Reports is an independent, nonprofit organization that works side by side with consumers to create a fairer, safer, and healthier world. CR does not endorse products or services, and does not accept advertising. Copyright © 2023, Consumer Reports, Inc.
Consumer Reports has no financial relationship with the advertisers on this site. Consumer Reports is an independent, nonprofit organization that works with consumers to create a fair, safe, and healthy world. CR does not endorse products or services and does not accept advertising. Copyright © 2023, Consumer Reports, Inc.