CBD is a compound found in hemp plants. Here’s what researchers know about its benefits and risks.

The best way to take CBD is by mouth, since smoking or vaping may cause lung issues. Pramote Polyamate/Getty Images
  • Unlike marijuana, CBD comes from hemp plants bred to have a very low concentration of THC, which means that CBD will not get you high.
  • There’s limited research on the effects of CBD, but some studies have found that it may help reduce pain and benefit patients with schizophrenia, anxiety, and addiction.
  • But CBD can cause side effects like nausea and sleepiness.
  • This article was medically reviewed by Zlatin Ivanov, MD, who is certified in psychiatry and addiction psychiatry by the American Board of Psychiatry and Neurology at Psychiatrist NYC.
  • Visit Insider’s Health Reference library for more advice.

Cannabidiol (CBD) is a compound found in marijuana and hemp plants that has recently skyrocketed in popularity. Companies market it as a remedy for everything from acne to high blood pressure.

While there are some preliminary studies on how CBD affects the body, more research is needed to understand all its different health benefits. Here’s what researchers know so far about CBD and its effects.

The difference between marijuana and CBD

Marijuana and CBD products both come from cannabis plants. The difference is that marijuana comes from plants that contain a larger amount of the psychoactive substance called Tetrahydrocannabinol (THC).

Whereas the industrial hemp plants bred for CBD products are required by US law to contain no more than 0.3 per cent THC. In other words, “CBD does not get you high,” says Houman Danesh, MD, the director of Integrative Pain Management at Mount Sinai.

The benefits of CBD

Though more research is needed, there is early evidence that CBD can help treat a wide variety of conditions including:


Many pain relief studies have looked at how CBD interacts with THC to help relieve pain, rather than CBD alone. Studies show that a THC-CBD combination can significantly decrease pain for both cancer patients and people with multiple sclerosis.


CBD has been shown to reduce activity in the areas of your brain that cause worry and fear. This may help explain why preliminary studies indicate that it helps with anxiety and insomnia.

For example, a small 2019 study involving 57 men found that taking 300 milligrams of CBD helped participants feel less anxious while doing a public speaking test. But oddly enough neither higher nor lower doses worked as well.


Early studies suggest that CBD may help people with addiction by decreasing their desire for the addictive substance. A 2013 study found that smokers who took CBD smoked fewer cigarettes during the study period.

Scientists are also hopeful that CBD can help prevent opioid users from relapsing. A preliminary 2015 study found that people addicted to opiates reported feeling fewer cravings when seeing images or videos of heroin for up to a week after taking CBD.


Early research suggests that CBD may help treat the symptoms of schizophrenia, including hallucinations and delusions. This could be an important finding because traditional medications that treat schizophrenia often have serious side effects like uncontrolled movements and significant weight gain.

Though scientists do not yet understand how CBD works to treat schizophrenia, a 2012 study found that 600 to 800 mg of CBD worked just as well as the standard antipsychotic medication therapy, but with fewer side effects. However, other studies have found CBD to be less effective.


The only CBD treatment that is approved by the FDA is for rare forms of epilepsy, a potentially life-threatening condition that causes seizures. Though scientists are still not sure exactly how CBD decreases seizures in epilepsy patients, it may help increase the availability of a brain chemical called adenosine, which can help to control seizures.

The risks of CBD

Though we know that CBD can cause side effects like nausea or sleepiness, we don’t yet know about more serious risks over the long term.

“The risks of CBD itself simply haven’t been studied,” says J.H. Atkinson, MD, co-director of the California Centre for Medicinal Cannabis Research.

One risk we are aware of is that CBD seems to interact with certain drugs like blood thinners, increasing how much of the drug stays in your bloodstream, Atkinson says.

The main risk of CBD products, however, is that they are not regulated by the FDA. This means that if you buy a bottle of CBD capsules, it may contain more or less CBD than the label says. “These fluctuations can be as high as 50-100% higher or lower than the stated claims,” Danesh says.

One way to help ensure that you’re getting the proper dose is to get CBD products that are 3rd party tested by an independent lab. For more details, LA Weekly has a list of CBD companies that use third party testing.

Types of CBD

CBD comes in many different forms, including edible gummies, vaping oil, tinctures, and skin cream. If you do decide to try CBD, it’s best to stick to methods that don’t involve smoking or vaping, as these can lead to lung issues. The safest way to take CBD is by mouth, Danesh says.

But even when taking CBD by mouth, there are some complications, Atkinson says. When you digest CBD, it can take much longer for the effects to start compared with smoking or vaping, so there is a risk that people may take too much, thinking it isn’t working.

There are currently no studies that show any major health risks from CBD, but for some people, taking high doses can cause side effects like diarrhoea or drowsiness. It’s also wise to proceed with caution since more research is needed to ultimately determine CBD’s effectiveness for certain conditions.

And remember, as with any new treatment, it’s best to discuss starting CBD supplements with your doctor first.

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