Is cannabis really helping you sleep?

Emily’s bedtime routine begins with a little weed, smoked on her porch, gazing out at the stars. At the end of a long day waiting tables and attending classes, it’s how she sheds the day’s worries and gets ready for sleep.

“It’s a decompression hour before I go to sleep, almost like a ritual,” she says.

Emily, a 23-year-old living in Portland, Oregon, who asked to use only her first name for privacy, has been smoking cannabis at night for a few years. Before she started this nightly ritual, Emily would often feel anxious before bed, or wake in the middle of the night, worrying. Weed helped.

“I started to like smoking pot at night because it would help me unwind. It would alleviate anxiety and an overactive mind,” she says.

Sleep is one of the most common reasons people seek out cannabis for non-recreational reasons, according to Nicole Bowles, who researches cannabis and sleep at Oregon Health and Sciences University. And as more states move to legalize marijuana, cannabis use overall is getting more common — herbal nightcaps included.

Sleep and substance abuse specialists say they’re concerned about the trend, which leads to long-term, nightly use of the drug.

“There’s some short-term beneficial effects at the expense of some potential long-term detrimental consequences,” says Carrie Cuttler, who researches the mental health impacts of chronic cannabis use at Washington State University.

However, cannabis is still widely perceived as a sleep aid. In a survey of more than 2,500 New England dispensary members, sleep was one of the top reasons why patients sought out medical cannabis, just behind “pain relief.”

The abundance of information and misinformation on the web is part of the reason behind this growing perception, according to Bowles. Sites publishing information and news on cannabis began springing up in recent years as more states opted to legalize. Leafly is one of the largest of these cannabis sites, with 15 million monthly visitors. It readily recommends hundreds of strains of cannabis for sleep and even calls marijuana “a well-known insomnia aid in the cannabis community.”

“We don’t have the research to back those claims at all,” says Bowles.

It’s hard to distinguish where information on the web comes from, and whether it’s evidence-based, she says. For instance, sites like Leafly are crowdsourced — meaning users who may or may not have expertise submit the reviews and articles.

But it’s not just the internet contributing to this perception. Dispensaries themselves are also recommending cannabis as a sleep aid.

In the state of New York, for example, insomnia is not a qualifying condition for medical marijuana. Still, says Sang Choi, a pharmacist at New York City-based dispensary, Etain, many patients she sees suffer from insomnia in addition to their qualifying condition, and come to the dispensary for help with both issues.

“We know that [cannabis] can help with sleep issues,” Choi says. “Our patients tell us that they’ve gotten really good sleep at night.”

Choi notes some of the improvement in sleep she sees is due to pain reduction. But she also adds that cannabis “helps restore a natural sleep cycle,” an assertion that Leafly has also made. This claim is more dubious.

Cannabis does make users feel sleepy and relaxed — that’s one of the drug’s main side effects, according to The Mayo Clinic. But does that mean the drug is actually improving sleep? Not necessarily, says Rubin Naiman, a sleep and dream specialist at The University of Arizona’s Center for Integrative Medicine.

“Certainly, cannabis can help you fall asleep,” he says, but that sleep isn’t necessarily good “just because your eyes are closed and you’re unconscious.”

There is some evidence that cannabis helps users fall asleep more quickly. However, other studies suggest the effect is largely subjective. A 1973 study found participants with insomnia given a high dose of cannabis fell asleep in 54 minutes — less time compared to participants given a placebo. However, data for the study was self-reported.

Results like these don’t tell us much about whether cannabis is helpful for sleep or not, says Bowles. She says she’s skeptical of self-reported sleep data — studies have shown the data’s often inaccurate, and it’s natural for people to perceive their sleep as better than it really is.

Studies done in the lab under controlled conditions can explicitly measure both the quantity and quality of sleep participants get. But these lab studies haven’t been able to replicate the effects found in self-reported data, according to a review of studies done prior to 2014. Often, researchers found, when an effect is there, it’s small. For example, one study found that participants given cannabis took two minutes longer to fall asleep than those given a placebo. Bowles says these studies deserve attention — not self-reported data — and two minutes isn’t a large enough difference to make any sweeping claims about cannabis, she says.

In reality, most cannabis users experience a negligible change not only in the amount of time it takes them to fall asleep, but the total time spent sleeping. For Emily, these results aren’t surprising. Although cannabis did help calm some of her middle-of-the-night worries, Emily (who never suffered from insomnia) never noticed a pronounced change in her sleep once she started smoking. 

“I don’t know that it does help my sleep, but I know that it doesn’t hurt it,” she says.

Researchers like Cuttler are concerned not that users will have worse sleep, but that once users start smoking cannabis, they won’t be able to sleep without it.

Insomnia is one of the main symptoms of cannabis withdrawal, which makes it even harder for users to cut back or quit. As many as 76% of regular users report poor sleep quality after quitting and that their sleep quality grew even worse over time, according to a 2015 study in the American Journal of Psychiatry. Another study found that these negative effects on sleep last for up to 45 days.

“The more you use, the more likely you are to have sleep disturbances,” Bowles says about users who try to wean themselves off cannabis.

Some sleep and substance abuse experts also worry cannabis’ effects on dreams.  Emily has noticed this herself. Although she feels more relaxed at night, her dreams stopped almost entirely once she started smoking at bedtime. This concerns her — not only does she miss dreaming, but she sees her dreams as a healthy part of sleep. And she’s right.

People who take cannabis before bedtime tend to get less REM sleep, the deepest stage of sleep when dreaming tends to happen. One early sleep study carried out in the lab found that cannabis reduced time spent in REM sleep by 18%, and total eye movement (an important indicator of the depth of REM sleep) by 49%.

Loss of REM sleep could have detrimental long-term impacts, including memory impairment. In fact, loss of REM sleep “may be part of the memory impairing effects of cannabis,” says Cuttler.

REM sleep is also crucial to our ability to regulate negative emotions, says Naiman. “The better we dream, the better we digest daily life experiences,” he says.

We don’t understand with absolute certainty the effect of cannabis on REM sleep, Cuttler says. Most studies on the REM-suppressing effects of cannabis were conducted in the 1970s and 1980s. Today, it’s almost impossible to research cannabis in a laboratory because of restrictions on schedule 1 substances, Cuttler adds. As a result, most recent studies are based on self-reported data or studies on rats and mice. Many of these studies also support the conclusion that cannabis suppresses REM, according to a review of research on the subject, but animal studies are not necessarily an indication of how a drug will affect humans.

Cuttler emphasizes that people looking into cannabis as a sleep aid should remember that it’s not a long-term solution. Instead, she recommends that people struggling to fall asleep try cognitive behavioral therapy for insomnia, a talk therapy that focuses on implementing good sleep habits and reducing anxiety around bedtime. Unlike medication or cannabis, cognitive behavioral therapy is not a quick fix, but its benefits have been shown to be long-lasting.

“I see cannabis very much as a Band-Aid treatment,” she says, “It temporarily alleviates the problem, but it can create more problems afterward as a result.”