Does Cannabis Actually Help With Sleep? Experts Say It Isn’t Risk-Free

We’re still a long way from fully understanding how weed impacts our sleep.

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Sleep — something all humans need — can be surprisingly elusive. In 2022, the global sleep aids market was valued at $78 billion. Whether it comes in the form of a drug, a tea, a new regimen, or something else, there are many products that claim to help you get a better night’s rest.

In recent years, many people have come to stand by cannabis as a solid sleep aid. While we know which receptors cannabis acts on in the brain, we still don’t know the biological mechanisms behind how it impacts sleep, experts say.

“It is safe to say that current research in no way answers the question of how cannabis impacts sleep,” Fiona Barwick, a behavioral psychiatry professor at Stanford University and director of the Sleep and Circadian Health Program, writes to Inverse.

But it's clear many people find it helpful.

This is especially true for those who live with chronic pain, as this substance seems to be an effective way to get some needed shut-eye. But as with everything, risks come with using cannabis to drift off. While there are far more questions than answers about how cannabis impacts our health, including sleep, it’s worth understanding the potential risks that come with using weed to snooze.

“It is safe to say that current research in no way answers the question of how cannabis impacts sleep”

You might develop a tolerance

“Any substance used regularly — whether alcohol, tobacco, cannabis, or prescription sleep aids — changes the brain,” Barwick says. This change often entails reduced sensitivity to the substance to maintain a constant functional baseline in the brain. In other words, you develop a higher tolerance to this substance. “Over time, this leads to reduced effectiveness, which often leads people to increase the amount of the substance they’re using.”

You’ll need higher doses to reach the point that lets you drift off to sleep. The great sleep you initially got from 2 milligrams of THC might require 5 milligrams after a few weeks, especially if you use it every day. We don’t have a clear idea, however, of how long tolerance takes to build because it varies depending on the cannabis strain, method of ingestion, and your unique brain chemistry. Tolerance also manifests differently in everyone, according to Karim Ladha, an anesthesiology professor at the University of Toronto. “We've seen people unable to tolerate even doses of five milligrams, and we've seen patients who feel absolutely nothing at 20 milligrams,” he tells Inverse.

Building up a tolerance could also mean you might find yourself using more products at once, so you need to buy them more frequently, or you start buying more expensive, higher-dose products. This is one sleep aid that can be prohibitively expensive. Cannabis products “can sometimes run you hundreds of dollars a month, and a lot of patients can't do that,” Ladha says.

And as tolerance builds, sleep quality can change.

You might sleep worse in the long run

Some immediately feel sleep relief from cannabis, making it an appealing option in the short term. “When used initially, cannabis appears to increase the amount of deep sleep somewhat, as well as reduce wakefulness at night, which is how people start using it as a nightly sleep aid,” Barwick writes. “At the same time, it suppresses our rapid eye movement [REM] or dream sleep, which is important for consolidating what we learn during the day and regulating our emotions.”

Tolerance also impacts sleep. “Over time, however, as tolerance increases, the percentage of deep sleep declines and the amount of time awake at night increases, especially with THC, leading to poorer sleep over the long term,” Barwick writes to Inverse. If you stop cold turkey, then your insomnia could be even worse than it was before, she writes. Ryan Vandrey, a behavioral pharmacologist at Johns Hopkins University, adds that forgoing weed after building a tolerance might also lead to unusually intense, vivid dreams.

You might experience dependence and withdrawal

If high doses of cannabis become part of your nightly bedtime routine, you run a higher risk of becoming dependent on it. As Ladha explains regarding tolerance, exactly what constitutes a high dose can vary for everyone.

After using it daily for months, stopping use can result in withdrawal effects like insomnia, irritability, tremors, nausea, depression, anxiety, and others. It could take up to three weeks for withdrawal effects to resolve on their own. This is, in part, why regularly consuming cannabis is high risk. At this point, you depend on cannabis not just to feel a certain way but to actively stave off the effects of withdrawal.

“What ends up happening is as you develop tolerance to it and use it on a daily basis for an extended period of time,” Vandrey says, “then stopping use can result in withdrawal effects.”

The bottom line, however, is that we’re still missing a lot when it comes to scientific knowledge about cannabis and sleep. “It is safe to say that current research in no way answers the question of how cannabis impacts sleep,” Barwick writes.

Vandrey recognizes the benefits and risks of using cannabis for sleep. From a research perspective, he just wants to see more evidence. “The current science doesn’t support people going to use [cannabis] as a first-line medication for sleep problems,” Vandrey says.

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