Cannabis has been used medicinally for centuries to treat a variety of ailments including chronic pain and nausea. Many people also turn to cannabis to help them fall asleep and stay asleep during the night. Here we’ll explore the science behind how cannabis affects the way we sleep.

Cannabis and Sleep Latency

One nearly universally experienced side effect of consuming cannabis is its ability to relax and sedate users. This can make falling asleep much easier for those who suffer from insomnia, a common sleep disorder that causes disturbances in the normal sleep cycle.

The effect of cannabis on sleep is not just anecdotal. Researchers have demonstrated that cannabis decreases sleep latency, the amount of time it takes to fall asleep.

Other studies found that cannabis improves subjective sleep quality, or how well users perceive their sleep. For adults, high quality sleep typically means falling asleep within 30 minutes, sleeping soundly with few awakenings, and drifting back to sleep quickly when you wake up during the night.

Cannabis and Sleep Cycles

Cannabis does more than help you drift off to sleep quickly. It can actually change your sleep architecture. Sleep architecture refers to the structure of your sleep which shifts between several physiologically distinct stages throughout the night.

There are two main categories of sleep.

  • Non-rapid eye movement (non-REM) sleep
  • Rapid eye movement (REM) sleep

Non-REM sleep is divided into four stages which represent increasing levels of deepening sleep. After falling asleep, we progress through these four stages before entering REM sleep. We then continue to cycle through the stages during the night with about 75-80% of the night spent in non-REM sleep and about 20-25% of the night spent in REM sleep.

Several studies from the 1970s found that THC, the primary psychoactive cannabinoid compound in cannabis, decreases the amount of time spent in REM sleep—the sleep stage most closely associated with dreaming—while increasing the amount of time spent in the deeper non-REM sleep stages.

Unfortunately, the long term effects of this type of change to the sleep cycle are still unknown. But although this research has yet to be replicated, it would explain why habitual cannabis users frequently report having fewer dreams. Similarly, cannabis cessation is often associated with an increase in vivid and strange dreams.

The Bottom Line

Both anecdotal and scientific evidence show that cannabis can have a significant effect on our sleep patterns. However, as is the case with many areas of interest involving cannabis treatment, more evidence is needed. It’s also important to note that while short term use may improve subjective sleep quality, habitual cannabis consumption tends to dampen the positively perceived effects of cannabis on sleep.

Lastly, not all strains are created equal. Different strains of cannabis can have surprisingly different effects based on their distinct chemovar. Comprehensive cannabis testing can help inform consumers and give growers and producers a detailed look at the cannabinoid and terpene profiles of their products.