The Difference Between CBD and THC

The Difference Between CBD and THC

CBD (cannabidiol) and THC (tetrahydrocannabinol) are the two main compounds found in the cannabis plant.

Each has unique properties, potential health benefits, and side effects.

The following article discusses CBD and THC, their effects, legal status, and safety considerations.

The man added CBD oil to his morning tea to use as medicine.

miodrag ignjatovic / Getty Images

The difference between CBD and THC

CBD and THC are known as cannabinoids. They have very similar chemical structures and activate the same receptors in the body endocannabinoid system.

This system is involved in essential body processes, including the following:

  • brain development
  • Regulation of the immune system
  • Pain perception
  • Motor control

Despite their similarity in structure, CBD and THC exert completely different effects.

Psychoactive vs. non-psychoactive

The most significant difference between these two compounds is that THC is psychoactive. This means it can affect how the brain works.

THC activates the body’s “reward” pathways to produce the “high” which is associated with marijuana use. It does this by activating or activating a cannabinoid receptor called CB1. When THC activates this type of receptor, things like movement, body temperature, and brain function are affected.

In contrast, CBD is not considered psychoactive. Does not cause euphoria or a “high”, even in large doses.

The Research

Cannabis products have been studied for the following medical conditions:

Much of the research on CBD and THC is preclinical, meaning it has been studied in animal models.

Large-scale human trials are needed to determine whether CBD or THC can help treat most of these conditions.

What is CBD?

CBD is commonly available in the following forms:

Although it acts on cannabinoid receptors, CBD primarily affects other receptors, including serotonin receptors.

It can help counteract some of the negative effects of THC, including serious side effects like psychosis.

CBD has many purported therapeutic properties. Research is limited, but some studies show it may benefit those with the following conditions:

  • pain. In general, there is not enough evidence that CBD alone helps with pain. Some research has shown that high doses can improve neuropathy (nerve pain), although more data are needed.
  • anxiety. So far, the results are mixed. Some studies show that CBD can improve symptoms of social anxiety disorder and post-traumatic stress disorder (PTSD), while others show no effect.
  • Seizures. Epidiolex, a purified CBD oil, is approved by the US Food and Drug Administration (FDA) for some difficult-to-treat types of childhood epilepsy.
  • Brain protection. Animal studies have shown that CBD may have benefits for those with Alzheimer’s disease or Parkinson’s disease, but human clinical trials are needed to verify these effects. Effects on animals may or may not translate into benefits for humans.

What is THC?

THC is the psychoactive ingredient in the marijuana plant. Possession and use of marijuana and products containing THC are not legal in all US states.

Aside from some prescription products, THC is available in the following forms:

  • cigarettes
  • Electronic cigarettes (vaping)
  • Edibles
  • Drinks

THC is effective for increasing appetite and for nausea and vomiting associated with cancer chemotherapy.

The FDA has approved the following THC-based prescription drugs:

  • Cesamet (nabilone), chemically similar to THC, taken for cancer-related nausea and vomiting
  • Marinol (dronabinol), synthetic THC (made in a lab), take for nausea and vomiting related to cancer or weight loss in people with AIDS
  • Syndros (dronabinol), a liquid for nausea and vomiting related to cancer or weight loss in people with AIDS

Other conditions for which THC may be effective include:

  • pain. Prescription THC products have been shown to improve neuropathy and quality of life.
  • Spasticity (muscle tension). Sativex (nabiximols), a mouth spray combining THC and CBD, is approved for spasticity in Europe.
  • PTSD. One very small trial found that Cesamet reduced nightmares in 10 servicemen with PTSD.
  • Irritable Bowel Syndrome (IBS). Smoking THC was found to improve IBS symptoms, but the benefits may be short-lived. People who used THC long-term were more likely to require surgery for IBS.

In particular, most research on the effects of THC has used standardized THC prescription drugs. Other THC-containing products available at dispensaries may or may not be beneficial for any of these conditions. More research is certainly needed.

Legality and regulation

Understanding how CBD and THC are regulated in the United States is a bit complicated. Basically, it comes down to where the product comes from, whether it’s from the marijuana plant or the hemp plant.

In 2018, the US legalized CBD containing less than 0.3% THC. Plants that contain this low concentration of THC are known as hemp. Historically, hemp has been used to make things like fiber and paper.

In particular, marijuana (which comes from a cannabis plant with more than 0.3% THC) remains a Schedule 1 controlled substance. This means that it is considered by the FDA to have a high risk of abuse and is not accepted for any medical use. Accordingly, CBD and THC that come from a marijuana plant are also Schedule 1 controlled substances. These are illegal in the US

The use of hemp-derived cannabis for medical purposes is legal in 47 US states as of 2024. This usually refers to CBD or THC in low concentrations (less than 0.3%). Some states also allow the recreational use of cannabis.

There are a lot of gray areas, though. If you’re traveling interstate, check the latest guidelines for the state you’ll be visiting. Some states do not allow products purchased in other states or only allow cannabis for specific medical conditions, for example.

To further complicate the picture, research shows that cannabis product labels are not always accurate. THC levels listed on a product label may be higher or lower than what is actually in the product. In general, there has been a marked shift towards higher and higher concentrations of THC in cannabis plants, making side effects and toxicity more likely.

Side effects and risks

CBD can cause the following side effects, which usually affect the gastrointestinal tract:

We don’t know much about the long-term effects of CBD; more research is needed.

CBD is also associated with a number of drug interactions, most of which involve drugs that are broken down by the liver. Some of the effects of CBD over prescription drugs or recreational drugs include:

  • Increased levels of seizure medications such as Onfi (clobazam) in the body
  • Increased sedative effects of alcohol
  • Increased levels of antidepressants, which can also increase the side effects of these medications
  • Increased risk of liver toxicity when combined with Tylenol (acetaminophen)

This list does not include everything. Be sure to discuss your medication list with your healthcare provider or pharmacist before taking a CBD product for optimal safety.

The side effects of THC it can be very serious. They often involve the brain and include:

  • Cognitive impairment, including problems paying attention, learning and remembering things. The risk of impaired mental function is higher among young THC users and those who use high concentrations.
  • Motor disability. Drivers under the influence of THC are twice as likely to be involved in vehicle crashes.
  • Risk of addiction. Although public opinion suggests that THC is safe, research shows that up to one in three people who use THC become dependent on it.
  • Anxiety and fear, especially if large doses are taken.
  • Psychosis, including hallucinations (seeing things that aren’t there) and paranoia
  • Seizures
  • Respiratory depression (shallow breathing), brain changes or coma in children.

In addition, long-term use of THC and THC-containing products, especially by inhalation (smoking or vaping), is associated with lung and heart disease.

THC has very negative impacts on the brains of children and adolescents. It is especially dangerous for these groups. THC can rewire reward and stress signals in the developing brain, increasing the chances of drug addiction and psychosis later in life.

Check out these amazing stats:

  • Teens who use THC are four times more likely to become dependent on THC than people who start using it in adulthood.
  • THC use before the age of 17 predisposes people to mental health conditions such as depression, anxiety and schizophrenia. Research shows that avoiding high levels of THC could prevent psychotic illness in nearly one in four people.

It is not clear whether THC works as a “gateway drug” by rewiring the addiction and reward functions of the brain. It’s possible that using THC can make it easier for someone to get hooked on a “harder” drug.


CBD and THC are the two main components of the cannabis plant.

They are similar in structure but have very different effects. THC is responsible for the “high” associated with marijuana use, while CBD does not alter the mind.

Although marijuana is still illegal in the US, CBD products that come from the hemp plant and contain less than 0.3% THC are legal in most states. Keep in mind, however, that this does not mean that CBD and THC are safe.

CBD can cause gastrointestinal side effects. There is very little data on its long-term use.

THC can cause serious effects on the central nervous system. These include anxiety, cognitive impairment and psychosis. THC is especially risky for children and teenagers because they are more likely to become dependent on it or develop mental health problems.

Hemp supply challenges since CBD plunged

Hemp supply challenges since CBD plunged