Cannabidiol (CBD) is an oil derived from the cannabis plant. Possible health benefits include reducing inflammation and pain. However, CBD oil is illegal in some states, and carries some health risks.

In June 2018, the Food and Drug Administration (FDA) approved the prescription use of Epidiolex, a purified form of CBD oil, for treating two types of epilepsy. Other forms of cannabis are legal in other states.

Cannabis contains a wide range of compounds, with varying effects. Some — but not all— are useful as a treatment. Similarly, some forms — but not all — are legal in some states.

This article will look at what CBD is, how it might benefit a person’s health, how to use it, any possible risks, and its legal status in the United States.

Is CBD legal?The 2018 Farm Bill removed hemp from the legal definition of marijuana in the Controlled Substances Act. This made some hemp-derived CBD products with less than 0.3% THC federally legal. However, CBD products containing more than 0.3% THC still fall under the legal definition of marijuana, making them federally illegal but legal under some state laws. Be sure to check state laws, especially when traveling. Also, keep in mind that the FDA has not approved nonprescription CBD products, and some products may be inaccurately labeled.

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CBD oil may help manage symptoms of chronic pain.

CBD is one of many cannabinoids (compounds) in the cannabis plant. Researchers have been looking at the possible therapeutic uses of CBD.

Two of the compounds in marijuana are delta-9 tetrahydrocannabinol (THC) and CBD. These compounds have different effects.

Until recently, THC was the best-known compound in cannabis. It is the most active constituent, and it has a psychological effect. It creates a mind-altering “high” when a person smokes it or uses it in cooking. This is because THC breaks down when a person applies heat and introduces it into the body.

CBD, in contrast, is not psychoactive. It does not change a person’s state of mind when they use it. However, it may produce significant changes in the body, and it is showing some significant medical benefits.

Find out more about the differences between CBD and THC.

Where does CBD come from?

CBD comes from the cannabis plant. People refer to cannabis plants as either hemp or marijuana, depending on how much THC they contain.

The FDA note that hemp plants are legal under the Farm Bill, as long as they contain less than 0.3% THC.

Over the years, marijuana farmers have selectively bred their plants to contain high levels of THC and other compounds that suited their interests.

However, hemp farmers rarely modify the plant. CBD oil comes from these legal hemp plants.

How CBD works

All cannabinoids produce effects in the body by interacting with cannabinoid receptors, which form part of the endocannabinoid system.

The body produces two receptors:

CB1 receptors are present throughout the body, particularly in the brain. They co-ordinate movement, pain, emotion, mood, thinking, appetite, memories, and other functions.

CB2 receptors are more common in the immune system. They affect inflammation and pain.

THC attaches to CB1 receptors but CBD stimulates the receptors so that the body produces its own cannabinoids, known as endocannabinoids.

CBD resources

Visit our dedicated hub for more research-backed information and in-depth resources on CBD.

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CBD may benefit a person’s health in various ways.

According to a 2018 study, reasons for taking CBD oil include:

  • chronic pain
  • arthritis or joint pain
  • anxiety and depression
  • sleep disorder
  • migraine
  • cluster and other headaches
  • post-traumatic stress disorder (PTSD)
  • nausea
  • cancer
  • allergies or asthma
  • epilepsy and other seizure disorders
  • multiple sclerosis (MS)
  • lung conditions
  • Parkinson’s disease
  • Alzheimer’s disease

There is some evidence to support some of these uses.

How does CBD help relieve pain? Learn more here.

Natural pain relief and anti-inflammatory properties

Conventional drugs can help relieve stiffness and pain, but some people see CBD as a more natural alternative.

There is growing evidence that the non-psychoactive compounds in marijuana, such as CBD, could provide a new treatment for chronic pain.

In 2018, mouse studies showed that CBD reduces inflammation by preventing the release of compounds that trigger inflammation in the body.

A 2019 study showed that CBD applied to the skin as an ointment significantly reduced inflammatory skin disease and scarring.

Quitting smoking and drug withdrawal

A 2013 pilot study found that smokers who used inhalers containing CBD smoked fewer cigarettes than usual and stopped craving nicotine. This suggests that CBD may help people quit smoking.


A 2018 study found that CBD helped reduce cravings during withdrawal from tobacco because of its relaxing effect.

Authors of a 2015 review found evidence that specific cannabinoids, such as CBD, may help people with opioid addiction disorders.

The researchers noted that CBD reduced some symptoms associated with substance use disorders. These included anxiety, mood-related symptoms, pain, and insomnia.

Research continues to support CBD’s use in managing withdrawal symptoms.

Epilepsy

After years of research into the safety and effectiveness of CBD oil for treating epilepsy, the FDA approved the use of Epidiolex, a purified form of CBD, in 2018.

They approved it for treating the following in people aged 3 years and over:

  • Lennox-Gastaut syndrome
  • Dravet syndrome

These rare forms of epilepsy involve seizures that are difficult to control with other types of medication.

Scientists are beginning to understand how CBD prevents seizures without the sedating side effects of medications used previously. Synthetic drugs are not yet available that target the endocannnabinoid system as CBD does.

Learn more here about Epidiolex (cannabidiol).

Alzheimer’s disease

Numerous studies have looked at the effect of CBD on Alzheimer’s disease.

In 2014, a rodent study showed that CBD might help people retain the ability to recognize familiar faces. People with Alzheimer’s can lose this ability.

One 2019 review found that CBD might help slow the onset and progress of Alzheimer’s disease. More research is underway to understand the dosage better. Some scientists believe a treatment involving both THC and CHD may be more effective.

Other neurological symptoms and disorders

Research suggests that CBD may also help treat complications linked to epilepsy, such as neurodegeneration, neuronal injury, and psychiatric diseases.

A 2012 study found that CBD may produce effects similar to those of certain antipsychotic drugs and that the compound may provide a safe and effective treatment for people with schizophrenia. However, further research is necessary.

Fighting cancer

Authors of a 2012 review found evidence that CBD may help prevent the spread of some types of cancer. The compound appears to suppress the growth of cancer cells and promote their destruction.

The researchers pointed out that CBD has low levels of toxicity. They called for more research into how CBD could support standard cancer treatments.

A 2020 review article discusses adding CBD to chemotherapy drugs to improve the immune system’s response to cancer treatment.

Other research has been looking at how CBD might help:

  • prevent the growth of cancer cells
  • reduce anxiety
  • improve the action of chemotherapy
  • lessen the side effects of conventional chemotherapy

Learn more here about CBD and cancer.

Anxiety disorders

Doctors have often advised people with chronic anxiety to avoid cannabis, as THC can trigger or amplify feelings of anxiousness and paranoia. CBD, on the other hand, may help reduce anxiety.

A 2019 study showed that CBD significantly reduced symptoms in mice with anxiety.

Authors of a 2015 review had previously suggested that CBD might help reduce anxiety-related behaviors in people with the following conditions:

  • PTSD
  • general anxiety disorder (GAD)
  • panic disorder
  • social anxiety disorder
  • obsessive-compulsive disorder

The authors noted that current treatments could have adverse effects, and some people stop using them for this reason. However, there is no evidence to confirm that CBD has significant adverse effects.

Type 1 diabetes

Type 1 diabetes occurs when the immune system attacks cells in the pancreas, leading to inflammation.

In 2016, researchers found evidence that CBD may ease this inflammation and protect against or delay the onset of type 1 diabetes.

In a 2018 study, CBD appeared to have neuroprotective effects on rats with diabetes, including helping preserve their memory and reducing nerve inflammation.

Acne

Acne treatment is another promising use for CBD. The condition is caused, in part, by inflammation and overworked sebaceous glands in the body.

A 2014 study found that CBD helps to lower the production of sebum that leads to acne, partly because of its anti-inflammatory effect.

Applying CBD topically may reduce inflammation in psoriasis and other inflammatory skin diseases, according to research.

CBD is becoming a more common ingredient in skin creams and ointments. However, some experts have concerns about the lack of evidence regarding its effectiveness and the lack of regulation.

The legal status of CBD in the U.S. is complex. Hemp and hemp-derived products are legal under the Farm Bill, as long as their THC content is less than 0.3%.

However, there is still some confusion over the specifics.

People should check the laws in their state and any travel destination.

It is worth remembering that the FDA have not yet approved any nonprescription products, which means people cannot be sure about what their product contains.

As with most therapies, CBD use may entail some risks. It may interact with supplements and other drugs. Most CBD products do not have FDA approval, which also means they have not undergone thorough tests.

It is not possible to know if a product:

  • is safe and effective for everyone to use
  • has the properties or contents stated on the packaging

Anyone who is using CBD – whether as a prescription drug or in other forms — should first speak to a doctor.

Possible adverse effects include:

  • liver damage
  • interactions with other drugs and alcohol
  • changes in alertness, which can make driving dangerous
  • gastrointestinal problems and loss of appetite
  • mood changes, including irritability and irritation
  • a reduction in fertility for males

Future research may prove CBD effective in treating various conditions. For now, however, the FDA urge people not to depend on CBD as an alternative to conventional medical care.

During pregnancy

Experts believe that using marijuana during pregnancy may affect the fetal development of neurons. Regular use among teens is associated with issues concerning memory, behavior, and intelligence.

The FDA advise people not to use CBD during pregnancy or while breastfeeding.

There are various ways of using CBD oil. These are not the same as using or smoking whole cannabis.

If a doctor prescribes CBD for epilepsy, it is important to follow their instructions.

Ways of using CBD products include:

  • mixing them into food or drink
  • taking them with a pipette or dropper
  • swallowing capsules
  • massaging a paste into the skin
  • spraying it under the tongue

Recommended dosages vary between individuals and depend on factors such as:

  • body weight
  • the concentration of the product
  • the reason for using CBD

Click here to learn more about CBD dosage.

There is growing interest in CBD as a therapy for various conditions, but only one product currently has FDA approval. Unapproved products are legal in some, but not all, states.

As regulation in the U.S. increases, more specific dosages and prescriptions will start to emerge.

For now, people should ask a healthcare professional for advice about which product to use and how much to take.

They should also research to ensure they are following regional and local laws. The FDA provide information about a wide range of issues relating to CBD use.