The Truth About Weed and Sleep
Does cannabis really help with shut-eye—or is that just a dream?
More and more people are using cannabis to sleep. One 2020 study found that this was one of the most common reasons people used medical marijuana, and according to SleepFoundation.org, some 70 percent of young people who use weed report they do so to help with snoozing.
To those who rely on a pleasant high to get some shut-eye, the logic behind this use feels intuitive: After consuming an edible, or smoking pot, many people feel a mellow calm set in, and this helps them launch off to dreamland with less tossing and turning.
But there are reasons to be wary of these anecdotal reports—and even of your own experience with sleep and cannabis.
“If you smoke a lot of cannabis or drink a lot of alcohol, you will be unconscious fast,” says W. Christopher Winter, a neurologist and host of the Sleep Unplugged podcast. “So, for a lot of people, that’s the metric they’re looking for—if I fall asleep fast, then I slept well, and if it takes me a while to fall asleep, then I didn’t.”
Instead, Winter says, people should consider, “Is this substance or chemical improving the quality or nature of your sleep?”
With beer and whiskey, we know that the answer is no. “Alcohol is an interesting cautionary tale of how something can appear like it’s helping you sleep but is actually making your sleep worse,” says Peter Grinspoon, an instructor at Harvard Medical School and author of Seeing Through the Smoke.
But the question of “does it induce quality sleep” is actually pretty hard to answer when it comes to cannabis. Research is limited and the answer is, well, about as hazy as Willie Nelson’s greenroom.
One paper published in 2022 in a BMJ journal examined a survey of 21,729 individuals and found that adults who used marijuana on 20 or more days in the past month were 64 percent more likely than the rest of the group to sleep less than six hours a night on average. Counterintuitively, members of this group were also 76 percent more likely to sleep longer than nine hours a night. It’s hard to take anything concrete from those figures, other than the fact that cannabis is probably not a reliable way to get an even eight hours of sleep. And, for the group that got a lot more sleep than that, it’s worth noting that more sleep is not always better. Extra sleep has been associated with poor health outcomes.
Another study published in January 2021 in the journal Addictive Behaviors looked at survey data from 152 moderate users of cannabis and found that frequency of recent use and the concentration of THC (the main psychoactive compound in cannabis) or CBD (an active ingredient in cannabis that does not cause a high) were “largely not associated with sleep outcomes.”
These types of survey-based studies are not as reliable as randomized controlled trials (people who decide to use cannabis as a sleep aid may have other factors affecting their sleep). But there are limited high-quality studies looking at the relationship between weed use and sleep. Those that exist, however, are similarly lukewarm on the promise of cannabis as a sleep aid.
One of the most robust to date is a meta-analysis published in the journal Sleep in 2022 that looked at 39 randomized controlled trials with a combined total of 5,100 patients. The majority of these trials, 33 of them, enrolled patients with chronic pain, including chronic cancer pain. Overall, a small percentage of patients, about 8 percent, saw sleep benefits from cannabis use in the studies. “That means you’d have to treat about 12 people with sleep problems with cannabis versus placebo to get one that says, ‘Yes, my sleep is now a little bit better,’ ” says Jason W. Busse, one of the study’s authors, and the associate director of the Michael G. DeGroote Centre for Medicinal Cannabis Research at McMaster University.
But even that result should be taken with a grain of salt, stresses Busse. For one thing, his research primarily looked at data from patients with chronic pain. Since cannabis has been linked to pain relief, it might provide more of a sleep benefit in this population. (That said: It’s also possible that those who suffer from this type of pain might have more intense sleep problems and get less benefit than the general public from cannabis.)
Busse and his co-researchers also found that, despite all the hype around the substance, there were some downsides to cannabis use. The most prominent was an increased risk of dizziness in users. This became more likely to occur over time among participants. In the studies, cannabis users were 29 percent more likely to experience dizziness, Busse says.
Some experts are optimistic that further research will bear out a clear benefit to taking weed for sleep. “I’ve been treating people for 20 years and I got a lot of success treating people with cannabis for insomnia,” says Grinspoon.
“There are thousands and thousands of people saying it works; it probably does,” says Benicio N. Frey, a psychiatrist and colleague of Busse’s at McMaster University. “I think it does work, but I don’t know to what extent.” Frey is leading a pilot study of 60 participants that will look at the impact of cannabis on sleep in people with a history of depression.
Frey notes that one issue with the research so far is that there’s almost no data comparing smoking to edibles or droplets, or on dosage levels, or on the role CBD versus THC might play. The answer to “Does weed help with sleep?” might well be that a certain dose delivered a certain way helps people with certain conditions sleep better—not that weed is or isn’t a good solution for the average person. “We need to be more granular in terms of understanding,” explains Frey.
Additionally, the studies included in Busse’s analysis didn’t examine how cannabis use influences sleep in the long term. The median follow-up for studies in the research was only 35 days. The long-term effect of cannabis as a sleep aid should also be studied, as there’s a chance that over time those who use cannabis to sleep might build a dependence on it.
“You may find it difficult to sleep without it if you get into a habitual pattern,” Busse says. In other words, cannabis helping you with sleep might become a self-fulfilling prophecy.
However, in this way, cannabis may not be so different from many other sleep medications. “When you look at medications for sleep, probably the biggest factor in their effectiveness is belief,” says Winter, who is skeptical of cannabis’ effectiveness for sleep (as well as that of most sleep medications). “If you believe the pills that you put in your mouth every night are helping with your sleep, and making you perform better the next day, that’s going to affect you more than what the pill actually does.”
If you do try cannabis for sleep, Grinspoon recommends erring on the side of too low of a dose to begin with, and using mostly CBD. Grinspoon believes cannabis carries less risk than common sleep medications such as Benadryl, benzodiazepines, and Ambien, which he notes have been associated with dementia.
Also, says Grinspoon: Have a conversation with your own doctor about the fact that you’re using weed to sleep, even if it’s a little awkward. This can help you better track whether cannabis is helping your sleep and also make sure it is not interfering with other medications you are taking. When these conversations don’t happen, people are left navigating the internet, and frequently find themselves on sites that tend to overstate the benefits of medical marijuana treatments.
This situation is exactly why researchers like Busse believe cannabis treatments need more attention and funding. “Let’s get some good studies on it so we can tell patients what their realistic expectations should be for both benefits and harms,” he says. “And let’s start to get this as part of the discussion that patients can have with their health care providers, so there’s less need to go out to the Wild West of the internet and have people figure out things on their own.”
