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Does weed help you sleep?

Many people believe cannabis and CBD products can be used as sleep aids, but the research shows mixed results.

A photo illustration that shows a white speech bubble with a series of emojis: a green tree, a puff of smoke, a sleeping face, and a red question mark. The background is a blue and pink gradient background.
(Washington Post illustration; iStock)
7 min

Many people say they turn to marijuana or CBD products as a way to help them sleep. But whether that edible, swallowed pill or inhaled hit soothes you to sleep may depend largely on how often you use it.

Researchers have known since the 1800s that the cannabis plant can have sleep promoting effects. The plant contains tetrahydrocannabinol, or THC, the main psychoactive chemical in marijuana which causes a “high,” as well as cannabidiol, or CBD, which is not psychoactive but may still affect your mood and feelings of well-being. THC and CBD have the same chemical formula but different structures, which is why they have different effects on the body.

The science on THC, CBD and sleep

But a variety of factors, including differences in state laws on legal use, have made the sleep effects of cannabis challenging to study.

Recreational cannabis can have varying levels of THC, making it difficult to parse through self-reported data because the actual dose used and resulting effects often aren’t clear. While clinical studies with pharmaceutical-grade THC are more controlled, the chemical used in lab studies often is nothing like the products people actually are using in the real world.

“When we’re looking at survey studies using recreational marijuana, you have no idea what it contains in terms of concentrations of various compounds and ratios to each other, and it’s very hard to replicate those findings,” said Bhanu Kolla, a sleep and addiction physician at the Mayo Clinic.

Another problem is that many of the cannabis studies that collect data on sleep come from patients with cancer or other chronic conditions. It may be that the drug is actually relieving pain, which allows the person to sleep better, but those findings do not offer insight into how the drug might help a healthy person sleep.

“From those studies, there is a slight signal that maybe cannabis products could improve sleep but that is specifically in the context of those conditions,” said Kolla. “It could be the pain is getting better so sleep is getting better. It’s very hard to extrapolate from that to say that the general population will have improved sleep.”

Maryland studied how much weed adults consume. It's a lot.

Daily marijuana use and sleep

While most experts agree that THC can promote sleep, how well it works depends on the specifics of the sleep problem and how much experience the user has had with the drug. In fact, daily users of cannabis typically report more sleep disturbances than less regular users.

The issue may be that regular users have developed a tolerance for the drug — meaning they may need a higher dose to achieve the same effect as someone who rarely uses it. Sleep problems can also result from cannabis withdrawal.

“Like alcohol, cannabis may improve sleep, particularly when used over short periods of time,” said Anastasia Suraev, a research fellow at the Lambert Initiative for Cannabinoid Therapeutics at the University of Sydney. Suraev disclosed that she has received consulting fees from Australia’s medicinal cannabis industry.

“When used regularly, [cannabis] can lead to tolerance and dependence, as well as disruptions to sleep architecture, resulting in worse sleep in the long term,” said Suraev. “These are the concerns that some specialists have that we are still trying to pinpoint and clarify.”

We thought our dog was having a stroke. She was stoned.

Ryan Vandrey, a professor in the department of psychiatry and behavioral sciences at Johns Hopkins Medicine, said people who use cannabis products for sleep should view them as they would any other sleep medication. Typically in sleep medicine, patients are rarely prescribed a medicine for longer than a few weeks at a time, he said.

“What happens is you take that medication every night and you become dependent on it to help you get to sleep,” said Vandrey. “It’s not as effective over time, you need to increase your dose, and ultimately trying to sleep without that medication, you end up being worse off than you started.”

Suraev also emphasized the importance of making sure people know how to safely withdraw from cannabis or THC-containing products — by gradually reducing their dose over time. “Stopping suddenly can make their sleep worse,” she said.

Smoking vs. edibles

How a drug is taken may also affect how people with sleep issues respond to cannabis. In controlled clinical trials in a laboratory setting, when adults who infrequently use cannabis are given vaporized THC, it has a stronger and faster effect. The study didn’t ​focus on sleep, but Vandrey says it’s reasonable to extrapolate ​the findings to sleep. ​

“If you’re trying to induce sleep, if you inhale the drug you’re going to get peak drug effects pretty quickly,” Vandrey said. “But with oral dose formulation it might takes an hour or three hours before the peak drug effects kick in. Topical dosing is going to take even longer.”

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Sativa vs. indica

It’s a common belief among cannabis users that different strains have different effects, and dispensaries may claim that a strain known as sativa is more energizing, while one called indica is more calming. Sativa is a tall slim plant with light green leaves, while indica is a short, bushy plant with dark green leaves.

The anecdotal evidence about differences in indica and sativa have not been supported by science and are “essentially meaningless,” said Vandrey. But when you interview people who use these products routinely and ask them about what kinds of effects they expect from an indica vs sativa, they will reliably say that they use indica to relax and sleep and sativa for focus or energy, he said.

“It’s unclear if that’s a true pharmacological difference of genetic plant lines or if it’s the expectation of the user that’s the kind of experience they’re going to have when they use that product based on the marketing that the industry uses,” he said.

Using cannabis to help sleep

If you want to try using cannabis for sleep, experts recommend starting with low doses and slowly increasing until you feel like it’s helping or you experience side effects. A common refrain, Suraev says, is “start low and go slow.”

CBD may also be another option for inducing sleep, and has less of a risk of dependence or withdrawal. However, study results for CBD as a sleep aid are mixed. Researchers caution that the compound also could interact with other drugs a person might be taking so it’s a good idea to talk to your doctor or pharmacist.

For many people, melatonin is a good option for sleep. Practical changes, like avoiding fluids before bed and keeping your room dark, can also help.

When Kolla is talking to his patients, he does mention cannabis compounds as a potential treatment. But given the lack of concrete evidence, he tends to steer them toward more evidence-backed approaches such as cognitive behavioral therapy and prescription medications.

“There are a lot of evidence-based good treatments for various sleep problems which should be what we attempt to use first,” he said. “Hopefully, with time and more research, we can clarify what, if any beneficial effects, THC, CBD or any combination would have. But we don’t have that yet.”

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