CBD might be able to affect sleep through several primary effects: pain reduction, stress reduction, and sedation. Depending on why someone is having trouble sleeping, any one of these effects might contribute to a better night’s rest.
Sleep is a complicated puzzle influenced by many different factors. First let’s explore why some people have trouble sleeping. Some people have sleep disorders, like insomnia, which prevent them from getting to sleep or staying asleep, despite how tired they might be. Other people may struggle with sleep due to chronic pain, which wakes them up during the night or makes them so uncomfortable they have trouble falling asleep. Additionally, some people may have anxiety that affects sleep. Finally, some people have trouble sleeping because they are plagued by nightmares or night terrors – as is common in people struggling with post-traumatic stress disorder (PTSD).
Based on current data, it seems that CBD might be able to affect sleep through several primary effects: pain reduction, dream suppression, stress reduction, and somnolence. Depending on why someone is having trouble sleeping, any one of these effects might contribute to a better night’s rest.
How Does CBD Affect Sleep?
Pain Reduction
CBD and other plant compounds found in the hemp plant are known as being potent modulators of the inflammatory response. Inflammation and pain are intimate partners. If someone is suffering from inflammation related pain, as might be found in chronic injuries or arthritis, CBD and CBD-rich hemp extracts might alleviate some of that inflammation, ultimately alleviated some of the pain. But not all pain is related to inflammation. What about nerve pain? The good news is that CBD and CBD rich hemp extracts might also help some people experience less intense neuropathic pain as might be found in conditions like fibromyalgia or neurodegenerative diseases. Ultimately whether CBD is reducing inflammation or improving neuropathic pain – that reduction in pain can sometimes help people get a better night’s sleep.
Dream Suppression
Some cannabinoids have the ability to interrupt REM cycles in sleep. For many people, this is not necessarily desired as it reduces dream activity and can sometimes actually make sleep worse. However, for people that are haunted by night terrors or nightmares, such as those suffering from PTSD, dream suppression can actually lead to better sleep and more rest. At lower doses, CBD can disrupt REM cycles by activating areas of the brain associated with wakefulness¹. In this way, CBD can prevent people from entering a deep sleep, avoiding dreaming. For those that do not want their dreams suppressed and are looking for a sedative effect, higher doses of CBD may be more beneficial.
Stress Reduction
Another way that CBD-rich hemp extracts might help sleep is by reducing feelings of stress and anxiety. Many people suffering from severe anxiety report that their mind will race while trying to go to sleep, leading to poor sleep. By reducing anxiety and calming the mind, some anxious users may find that their sleep subsequently improves. In one recently published study from 2019, 72 adults exhibiting anxiety or poor sleep were treated with CBD and the researchers found that CBD successfully decreased anxiety in 80% of patients and improved sleep over the first month of the study in 67% of patients². In another study, researchers examined whether treating anxiety with CBD would disrupt normal wake-sleep patterns and found that anxiety relieving doses using CBD did not disrupt sleep³. This may be related to the fact that low doses of CBD can be stimulating, but high doses can be sedating.
Somnolence/Sedation
One of CBD’s side effects is somnolence, which is essentially the feeling of being drowsy or tired. This effect is dose dependent and tends to occur at higher doses than lower doses. At a low serving size, as mentioned in the previous section on dream repression, it has been shown that CBD can exhibit stimulating effects, which would be helpful for daytime but would not be helpful for treating many sleep deficiencies. One study found that 15mg of CBD appeared to be stimulating and counteracted the sedating effects of THC⁴. A rodent study from 1977 found that rats given servings of 40mg/kg were less wakeful but did not experience modifications to REM sleep⁵. If undesirable somnolence/sedation is experienced after taking CBD, the dose may need to be reduced.
A Discussion on Dosing
When it comes to finding the right dose for nighttime – this discussion might be helpful. As mentioned above, a light dose of Full Spectrum CBD can exhibit wakefulness and stimulating effects which is desired for daytime. While a larger dose of Full Spectrum CBD can cause sedation which is more beneficial for nighttime use.
In the daytime, if undesired sedation or tiredness is experienced after taking CBD, the dose may need to be reduced (you may find that reducing that amount by half will not cause daytime sedation). In other words, take a smaller dose during the morning or day for desired wakefulness yet calming effects. At nighttime, if wanted sedation and sleepiness is needed, the CBD dose may need to be larger or increased (you may find that increasing the daytime amount by 2x – 3x may help with relaxation and sleep at night). This occurs because CBD is biphasic – meaning it has two distinct phases. A small amount of CBD affects the body differently than a larger amount.
Will I become tolerant to CBD’s effects on sleep?
With chronic use, tolerance to CBD’s effects on sleep is likely to develop. This tolerance can be interrupted by taking a break from CBD, or sometimes just trying a different CBD product with a unique chemistry can interrupt the development of tolerance. There are other cannabinoids present in Cannabis which may also be beneficial for sleep, like cannabinol, or CBN. It may be possible to reduce the effects of tolerance by switching between products that have more or less CBN or other cannabinoids.
¹ Murillo-Rodriguez E, et al. The nonpsychoactive cannabis constituent cannabidiol is a wake-inducing agent. Behavioral Neuroscience. 2008. 122(6): 1378-382
² Shannon S et al. Cannabidiol in anxiety and sleep: a large case series. Perm J. 2019. 23:18-041
³ Linares IMP, et al. No acute effects of cannabidiol on the sleep-wake cycle of healthy subjects: a randomized, double-blind, placebo-controlled, crossover study. Front Pharmacol. 2018. 9:315
⁴ Nicholson AN et al. Effect of delta-9-tetrahydrocannabinol and cannabidiol on nocturnal sleep and early-morning behavior in young adults. J of Clin Pharmacol. 2004. 24(3): 305-313
⁵ Monti JM. Hypnoticlike effects of cannabidiol in the rat. Psychopharmacology. 1977. 55(3): 263-265
Please use this as a guide and not medical advice. Written in collaboration with Jason Wilson, MS – a science educator, natural products researcher, an expert on cannabis and cannabinoid science, and creator of the Curious About Cannabis Podcast.