People have long used the cannabis plant for medicinal and recreational purposes. Compounds called cannabinoids in the plant are responsible for the effects on the brain, and the two most abundant of these are tetrahydrocannabinol (THC) and cannabidiol (CBD).

THC and CBD are both psychoactive, but they affect the brain differently. Unlike THC, CBD is nonimpairing.

People use CBD for a variety of reasons, including reducing seizures, anxiety, and pain.

Some studies have demonstrated that CBD may also be a sleep aid. In this article, we look at whether it works and any associated risks.

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Some people may benefit from taking CBD as a sleep aid.

In the last decade, growing public interest in the benefits of marijuana, and CBD in particular, has encouraged researchers to study its effects.

Early studies indicate that high dosages of CBD may support sleep.

One investigation found that, compared with a placebo, a CBD dosage of 160 milligrams (mg) increased sleep duration. The researchers also concluded that the placebo, 5 mg of the insomnia drug nitrazepam, and 40, 80, and 160 mg of CBD helped the participants fall asleep.

Levels of cortisol, the stress hormone, typically peak in the morning, but people with insomnia may have high cortisol levels at night. Independent of insomnia, having high cortisol levels at night is associated with an increased number of nighttime awakenings.

In one study on the effects of CBD, researchers found that cortisol levels decreased more significantly when participants took 300 or 600 mg of CBD oil. These results suggest that CBD affects the release of cortisol, possibly acting as a sedative.

A more recent analysis of CBD and sleep recruited 103 participants who had anxiety or poor sleep. The researchers studied the effects of CBD combined with those of other prescribed medications.

The CBD dosages ranged from 25–175 mg. The researchers found that 25 mg was the most effective dosage for anxiety and that addressing troubled sleep required higher dosages.

During the 3-month study, the investigators followed up with the participants monthly. At the first follow-up, 66.7% reported an improvement in sleep, but 25% had worsened sleep. At the second, 56.1% of the participants reported improved sleep, but 26.8% had worsened sleep.

The researchers conclude that although CBD might help people sleep in the short term, the effects may not be sustained.

Overall, the available evidence suggests that CBD is well-tolerated.

Some people report fatigue and mental sedation with CBD use, but researchers believe that this may be related to the dosage.

Taking 10–400 mg of CBD per day for a long period and by different routes did not have a toxic effect on participants in a large retrospective study. Even dosages of up to 1,500 mg per day were well-tolerated, other researchers report.

However, determining whether there are long-term risks of CBD use will require further studies.

So far, no reports of lethal CBD overdoses exist. Some researchers may be concerned about CBD abuse, but information on significant complications is limited.

One study indicates that dosages of 400–700 mg of CBD, which are considered high, can aggravate cognitive deficits in people with schizophrenia. Combining CBD and THC may, however, improve cognition.

Researchers do report that CBD may cause other adverse effects, including:

  • alterations of cell viability, in studies conducted in cell cultures
  • decreased fertilization capacity
  • inhibition of drug metabolism in the liver
  • decreased activity of P-glycoprotein and other drug transporters

If these effects on drug metabolism and transportation are confirmed, it would indicate that CBD interferes with other medications. Overall, more research is necessary.

Still, it is a good idea for anyone who wants to use CBD to speak with a healthcare provider first.

CBD has several properties that may make it an attractive therapeutic agent.

Researchers are interested in its effects on:

  • anxiety
  • other psychiatric disorders
  • nausea and vomiting
  • inflammation

The first CBD-based medication approved by the Food and Drug Administration (FDA) is Epidiolex, which doctors prescribe to treat rare and severe forms of epilepsy.

Sativex is a CBD and THC combination medication used to help ease spasticity in people multiple sclerosis. However, the FDA has not approved this for use in the United States.

Researchers believe that CBD may also help treat or prevent:

However, the capacity of CBD to address these issues remains unclear, and further research is necessary.

Learn more about the potential effects of CBD oil here.

The mainstay of insomnia treatment is behavioral therapy. Some effective techniques include:

  • relaxation techniques
  • stimulus control therapy
  • sleep restriction therapy
  • sleep hygiene practices
  • paradoxical intention therapy
  • cognitive restructuring

Some people may still require medications. Doctors may recommend controlled-release melatonin or prescribe doxepin for adults.

Or, they may recommend a Z-drug — a class of medications that help people stay asleep. Among them are zolpidem (Ambien), eszopiclone (Lunesta), and zaleplon (Sonata).

Benzodiazepines can help people sleep, but doctors do not recommend them as a sleep aid because of their high abuse potential.

Other sedative drugs that people sometimes use to support sleep include:

  • antihistamines
  • antiepileptics
  • atypical antipsychotics

However, doctors do not recommend these as sleep aids unless a person requires them for another purpose.

Insomnia is common, particularly among older adults and people with other medical and psychiatric disorders.

Anyone who has trouble sleeping should speak with a doctor and avoid self-medicating. A person may be experiencing:

  • trouble falling asleep
  • trouble staying asleep
  • poor sleep quality

The best approach to treatment depends on the type of difficulty sleeping, but a doctor may recommend behavioral therapy, medication, or a combination.

Anyone who thinks that they may be taking too many sleep aids or who is experiencing adverse effects of a sedative should speak with a doctor.

Insomnia is a common condition, and doctors typically recommend behavioral changes, sometimes in combination with prescription drugs.

Some people try to self-medicate sleeping problems with CBD. Taking CBD appears to be generally safe, though research into its effects, particularly in the long term, is limited.

Doctors are unsure whether CBD helps people sleep, but some evidence suggests that it may improve sleep duration.

Determining the most effective way to take CBD and the right amount to support sleep will require more studies.