Meet the special compounds that give cannabis its strange powers.
You know that marijuana has a unique influence on the body, but have you ever stopped to wonder why? Medical marijuana has been used since ancient times, and more recently, researchers set out to figure out why the body responds to cannabis sativa the way that it does.
The short answer: Marijuana speaks the brain’s language.
Meet the Endocannabinoid System
One of the first thing researchers realized in their quest to understand how marijuana affects the body is that cannabis contains a number of active chemical compounds—over a hundred, in fact. The first, named THC, was discovered in the 1960s. Researchers dubbed these compounds cannabinoids.
As they studied cannabinoids, it became clear that these active compounds were interacting with receptors in the body. These receptors belong to the body’s complex nerve system, which uses neurotransmission to send and receive messages between the brain and the rest of the body. By interacting with these receptors, the cannabinoids were essentially altering the brain’s normal communication.
This left the researchers with an important question: What allows these cannabinoids to interact with these specific receptors?
That’s when they realized the body makes its own version of cannabinoids. Beginning in 1992, researchers discovered that certain cannabinoids in cannabis actually resemble the molecular structure of the body’s own cannabinoids, according to a 2018 study in International Journal of Molecular Sciences. Researchers named these endocannabinoids (since the prefix endo– means “within”).
Endocannabinoids are neurotransmitters, meaning they help send nerve impulses to the brain to trigger different effects on the body. Because cannabinoids (from cannabis) look and act like endocannabinoids (from the body), the brain recognizes them and allows cannabis to affect behavior, mood, coordination, and more.
Let this sink in: The fact that cannabinoids were discovered *before* endocannabinoids means that some of our natural neurotransmitters are named after a cannabis term (crazy, right?).
Meet the Cannabinoids
Although scientists have identified at least 113 cannabinoids so far, the two most studied are THC and CBD.
THC is short for delta-9-tetrahydrocannabinol, and it’s responsible for marijuana’s most well-known effects:
A euphoric “high”
Altered sense of time
Slower reaction time
Loss of coordination and balance
And reduced pain.
THC works because it very closely mimics the chemical structure of the endocannabinoid known as anandamide, according to the National Institutes of Health. Both THC and anandamide interact with receptors known as CB1 receptors. Like THC, anandamide can also affect things like perception of pain and sense of reward, but not at the same levels of THC.
Researchers also identified a different group of receptors called CB2 receptors, with which THC interacts but anandamide does not. Most CB1 receptors are part of the central nervous system (like the brain and spinal cord); most CB2 receptors are part of the immune system. This explains why marijuana has both psychoactive and therapeutic effects.
CBD is short for cannabidiol. It doesn’t act on CB1 or CB2 receptors, so it has much different effects than THC. Most notably, CBD does not cause a “high.” Instead, it’s known for having a calming effect. Some research suggests CBD may be able to:
And quiet anxiety.
Researchers are still identifying which receptors CBD acts on, but they know a few of them. They know CBD interacts with a serotonin receptor called 5-HT1A, which could explain its anti-anxiety effect. They also know it interacts with receptors known as the vanilloid receptors, specifically one called TRPV1, which is known to influence the body’s perception of pain.
Moral of the story: Cannabis has a fascinating effect on the body, and researchers are still studying exactly what those effects are. However, it’s a good idea to study up on cannabis before investing, since some health claims and marketing tactics can be misleading.
Want more weed wisdom?
Cannabis and cannabinoids (PDQR)-patient version. Bethesda, MD: National Cancer Institute. (Accessed on April 2, 2019 at https://www.cancer.gov/about-cancer/treatment/cam/patient/cannabis-pdq?redirect=true.)
How does marijuana produce its effects? Rockville, MD: National Institute on Drug Abuse. (Accessed on April 2, 2019 at https://www.drugabuse.gov/publications/research-reports/marijuana/how-does-marijuana-produce-its-effects.)
Lafaye G, Karila L, Blecha L, Benyamina A. Cannabis, cannabinoids, and health. Dialogues Clin Neurosci. 2017 Sep;19(3):309-16.
Marijuana and cannabinoids. Bethesda, MD: National Center for Complementary and Integrative Health. (Accessed on April 2, 2019 at https://nccih.nih.gov/health/marijuana.)
NIH research on marijuana and cannabinoids. Rockville, MD: National Institute on Drug Abuse, 2018. (Accessed on April 2, 2019 at https://www.drugabuse.gov/drugs-abuse/marijuana/nih-research-marijuana-cannabinoids.)
What are marijuana effects? Rockville, MD: National Institute on Drug Abuse. (Accessed on April 2, 2019 at https://www.drugabuse.gov/publications/research-reports/marijuana/what-are-marijuana-effects.)
Zou S, Kumar U. Cannabinoid receptors and the endocannabinoid system: signaling and function in the central nervous system. Int J Mol Sci. 2018 Mar;19(3):833.