Understanding Cannabis and Cannabinoids (THC and CBD)

Cannabis is a plant that can be used in different forms to help people manage symptoms of cancer and its treatment. You may hear terms like marijuana, hemp, THC, and CBD, but they all refer to different parts or chemicals found in cannabis plants. Understanding these differences can help you make informed decisions about what might be right for you.

What is cannabis?

Cannabis refers to a group of more than 700 plant varieties that come from the Cannabaceae family. Cannabis sativa and Cannabis indica are the two varieties (sometimes called strains) most often used in inhaled, ingested (edible), and topical cannabis products.

• Cannabis sativa is known for enhancing mood, energy, and mental focus. It has long, thin leaves and a light green color.
• Cannabis indica tends to have a calming, relaxing effect. It has shorter, darker green leaves.

A third variety, Cannabis ruderalis is less commonly used in cannabis products because it has lesser effects. But it is usually crossbred (hybridized) with sativa or indica to make hardier, faster-growing plants. 

• Hybrid cannabis describes a cannabis plant that’s been crossbred from different varieties of cannabis plants.
• Blended cannabis describes a product made by mixing different varieties of cannabis plants. A blended cannabis can include pure or hybrid varieties.

What are THC and CBD?

THC and CBD are two of the main chemicals in cannabis that have psychoactive or medicinal effects on the body. They are both part of a group of more than 100 different types of chemicals called cannabinoids, which are found in cannabis plants. Some cannabinoids are also made naturally in the body. They can also be made artificially in a lab.

Because they are found in plants, THC and CBD are sometimes called phytocannabinoids. (“Phyto” refers to anything related to plants.)

THC and CBD affect your body in different ways:

• THC (delta-9-tetrahydrocannabinol) is a psychoactive chemical. This means it can affect how your brain works. It’s the main ingredient in marijuana and other cannabis products that produce a feeling of being “high” or a sense of euphoria or intense happiness.
• CBD (cannabidiol) can change how you feel pain and how your body responds to inflammation from an injury or a health problem. It can also create a feeling of relaxation. It does not have psychoactive effects. This means it doesn’t cause the type of “high” feeling that THC is known for.

The endocannabinoid system

Our bodies naturally make certain types of cannabinoids as needed. “Endo” means “within,” so cannabinoids made by the body are called endocannabinoids. They are found in various organs and tissues. The reason THC and CBD have the effects they do is because the body has receptors (proteins that can change the way a cell acts) that are activated by cannabinoids, whether they are made by the body or come from a plant.

When the body detects pain, hunger, injury, or stress, the endocannabinoid system (ECS) becomes active to help transmit signals between nerve cells. Cannabinoids react by attaching or binding to cannabinoid receptors, such as CB1 and CB2.

• CB1 receptors are found in your brain, nervous system, and in some organs that help control how you feel pain.
• CB2 receptors are found in many organs and parts of your body. They mostly work with the digestive and immune systems by responding to signs of inflammation or injury and related symptoms, such as nausea and anxiety.

THC binds directly to CB1 receptors, which is why it has the effects it does. CBD doesn’t bind to receptors directly. Instead, it supports the body’s own endocannabinoids and helps to regulate the endocannabinoid system.

Synthetic cannabinoids

Synthetic cannabinoids are made in a lab. They are meant to have similar effects of cannabinoids found naturally in plants and the body. Nabilone is an example of an FDA-approved synthetic cannabinoid available as a prescription. However, many others are much stronger and are known to have harmful side effects. These non-prescription synthetic cannabinoids can be hazardous due to uncertain effects that might cause serious health problems.

What are marijuana and hemp?

Marijuana and hemp are both products made from cannabis plants. They differ in which parts of the plant they use and how much THC they contain.

Marijuana is the name given to the dried leaves, flowers, and seeds of varieties of cannabis plants. It goes by many names, including pot, grass, cannabis, dagga, weed, delta, hemp, hash, flower, buds, marihuana, ganja, and many others. Marijuana contains both THC and CBD.

Hemp is made up of the stalks, stems, and seeds from cannabis plants. Like marijuana, hemp contains both THC and CBD. While both can have varying amounts of CBD, hemp has less THC than marijuana does.

According to the US Food and Drug Administration (FDA), “marijuana” is any cannabis product with more than 0.3% THC and “hemp” is any product with 0.3% or less of THC. Marijuana is considered illegal by federal law, even though some states have legalized it. Hemp is not considered illegal by federal law due to its lower concentration of THC. Read more in Is Cannabis Legal in the US?