An illustration of a man sleeping with a pot-leaf eye mask

People have been turning to cannabis for its possible health benefits for a long, long time. Its ability to help people, for example, is mentioned in the Atharvaveda, a Hindu text that dates back to around 1500 B.C., and its use for inducing sleep is described in a 1200 A.D. Chinese medical text. 

Today, people are still using cannabis to help them sleep, particularly one form of it: CBD, or cannabidiol. That’s a compound found in marijuana and hemp that doesn’t get you high, and that has recently exploded in popularity because of its potential to treat other health problems, including pain and anxiety.

In a recent nationally representative Consumer Reports survey, about 10 percent of Americans who reported trying CBD said they used it to help them sleep, and a majority of those people said it worked. 

More on CBD

It’s easy to understand why people are turning to CBD to help with sleep: Almost 80 percent of Americans say they have trouble sleeping at least once a week, according to another recent nationally representative CR survey of 1,267 U.S. adults. And many existing treatments, particularly prescription and over-the-counter drugs, are often not very effective—and are risky, too.

A small but growing body of scientific research provides some support for CBD as a sleep aid. A study out this month, for example, suggests CBD might help people with short-term sleep problems.

And Joseph Maroon, M.D., a clinical professor and neurosurgeon at the University of Pittsburgh Medical Center who has researched the effect of cannabis on the brain, says that CBD has properties that could help some people sleep better. Most notably, he says, it appears to ease anxiety and pain, both of which can make it harder to fall asleep or stay asleep.

Some other research hints that CBD may also affect sleep directly, by interacting with receptors in the brain that govern the body’s daily sleep/wake cycles, according to a 2017 review of sleep and cannabis in the journal Current Psychiatry Reports.

But “many questions still remain as to timing, the amount to take, and route of dosing CBD for sleep,” Maroon says. All of that could affect who CBD helps for sleep, and who it doesn’t.

And how it affects people does seem to be hit or miss. For example, Melissa Giovanni, age 32, a licensed dietitian in Nashville, Tenn., takes CBD regularly for sleep and says it often helps. But Liz Fuller, age 47, a makeup artist in Boston, says she tried two different CBD brands—spending about $135—to treat her insomnia, and neither worked. 

Maroon says he doesn’t see CBD as a treatment for insomnia, but instead as an “alternative natural method to help calm anxious thoughts that often delay or interrupt natural sleep.” He points out that next to nothing is known about the safety or effectiveness of CBD in children, pregnant women, or older people when used for sleep or anxiety. Maroon urges those with insomnia to see their doctor before using any treatment.

Still, he notes that if you occasionally have difficulty sleeping, CBD is considered a safe, non-habit-forming, natural alternative.

For those looking to try CBD to see whether it helps improve sleep, here’s what you need to know.

How CBD Might Help With Sleep

One way CBD may help with sleep is by easing anxiety. In a study in the January issue of The Permanente Journal, published by the Kaiser-Permanente health insurance company, Colorado researchers looked at the health records of 72 patients who were treated with CBD for either anxiety or poor sleep.

During the three-month study, anxiety levels did decline, even in people whose main complaint was poor sleep. For those with sleep problems, the results weren’t as clear cut, though people did report some improvement in the first month.

Those benefits might be due to the placebo effect, says Scott Shannon, M.D., the study’s main author and an assistant clinical professor of psychiatry at the University of Colorado-Children’s Hospital in Denver. But Shannon, who is also founder of the Wholeness Center, an integrative medicine clinic in Ft. Collins, Colo., also thinks that some people may have slept better because they "worried less about their sleep issue."

Scientists have some biological explanations for how CBD may affect both sleep and anxiety. Recent studies have shown that cannabis compounds interact with receptors throughout the body—the so-called endocannabinoid system—including in the brain. At least one of those type of receptors is thought to affect the body’s sleep/wake cycle, offering one explanation for how CBD could affect sleep directly. And CBD also interacts with another receptor in the brain that researchers have linked to anxiety.

Should You Try It?

Shannon and other experts we spoke with say that before turning to CBD for sleep, you should try more proven therapies. The best evidence is for a form of therapy called cognitive behavioral therapy for insomnia, or CBT-I, which focuses on changing habits that disrupt sleep. Research shows it's more effective and safer than prescription or over-the-counter sleep drugs, which can cause dependence and pose a risk of overdose and death. 

Although CBD’s benefits for sleep are still unclear, Shannon notes that CBD poses few side effects. The most common one in his study was fatigue. Other common side effects can include diarrhea and changes in appetite and weight.

If other remedies haven’t helped and you want to give CBD for sleep a try, experts we spoke with said here are some things to consider:

CBD may work better for anxiety than sleep. There's more evidence for CBD's ability to ease your anxiety than to help you fall asleep, though helping you relax could help you sleep, too. 

Short-term use might be best. CBD’s ability to improve sleep may diminish the longer you use it, so you may not want to use it daily or long-term. In Shannon’s study, people whose main complaint was sleeplessness improved in the first month, but then faded during months two and three. And Michael Backes, an expert in cannabis science and policy and author of “Cannabis Pharmacy: The Practical Guide to Medical Marijuana” (BDL/Hachette, 2014), says his research and interviews with users suggest that once a person is no longer chronically sleepy, CBD might, paradoxically, keep people awake.

Higher doses could work better. There’s not much research on dosing, but what there is suggests low doses might not be very effective. A 2004 study found that low doses (15 mg in this case) didn’t help people fall asleep and might actually have made people more wakeful. And an even earlier study found that a relatively large dose—160 mg—worked better than a lower one. In Shannon's study, patients were given a 25 mg dose.

Mitch Earleywine, Ph.D., a professor of psychology at the University at Albany, State University of New York, and on the advisory board the marijuana advocacy group NORML, suggests starting with a modest dose of 30 mg and slowly working up if that doesn’t work. And he cautions that a dose of 160 mg “is going to be incredibly expensive.”

Consider the form. Vaping CBD might work faster, because that quickly gets the compound into your system, says Earleywine, who is also the author of “Understanding Marijuana” (Oxford University Press, 2005). But pills, oils, and edibles such as gummy bears might help you sleep longer, because they release the CBD more slowly. If you opt for one of those forms, Earlywine suggests taking it about an hour before bedtime. (Read more about the different forms CBD comes in and how they affect the body differently.)

Look for quality products. Some studies suggest that many CBD products don’t have what they claim or are contaminated with pesticides or other harmful substances. (Read more about how to shop for CBD products.)

Use it safely. Last, talk with your doctor—especially if you take other meds—because CBD may interact with medications. (Read more about how to use CBD safely.)