Cannabis 101: What is THC and CBD?

You have probably become aware of the fact that cannabis legalization is happening fast. Ten statesin the US now have some form of law that has expanded or completely legalized recreational marijuana.

Whether you are an avid user of cannabis, know people who are, or are simply curious about what all the hype is about, it’s important to know how cannabis affects your brain and body (so you don’t end up uncomfortably stoned on the floor of some friend-of-a-friend’s apartment…don’t worry, you’re not alone).

Knowing a little about the compounds in cannabis can help you choose the right strain and the right dose for you.

What is THC?

∆9-Tetrahydrocannabinol, or THC, is the chemical produced by cannabis that’s responsible for the feeling of being “high.” THC activates receptors in our body called cannabinoid (CB) receptors. These receptors are part of a system called the endocannabinoid (eCB) system.

The eCB system is widespread throughout the brain and body. In the brain, studies showthat CB1 receptors present in the forebrain affect executive functioning and decision making, and those in the hippocampus play an important role in memory.

CB receptors are also widespread throughout the body, present in places like the lungs, gastrointestinal tract, and the immune system. Not surprisingly then, the endocannabinoid system is responsible for a multitude of bodily processes like appetite, pain modulation, memory, mood, and a vast array of others.

There are two known chemicals naturally produced by our body that activate receptors in the eCB system—2-arachidinoyol-glycerol (or 2-AG) and anandamide.

These chemicals contribute to the eCB system’s role of homeostatic regulation—which is basically your body’s way of checking in with itself and making sure things don’t get too out of whack.

When you smoke cannabis (or eat it, swallow it, vape it, rub it, or consume it by any other method), THC enters the brain and binds to these receptors. THC is now present, making it harder for the cannabinoids that our body naturally produces to do what they do best, and this can throw off homeostatic regulation. This is why you might get “the munchies” or find that your memory is not the best after you smoke—because THC is taking the place of the chemicals that normally regulate appetite and memory.

However, you probably know that there are benefits of cannabis too. THC has been known to help people with insomnia by partially restoring the regulation of sleep. It also helps those who struggle with eating disorders by restoring appetite.

THC is just one of over 100 cannabinoids in cannabis—cannabidiol, or CBD, is another main chemical in cannabis.

What is CBD?

CBD is the primary non-intoxicating (meaning it doesn’t make you feel high) cannabinoid found in cannabis, and when given to people with epilepsy, has reduced the instance of seizures by almost 40%.

CBD helps cancer patients endure chemotherapy and weakly activates some CB receptors that regulate inflammation. It also works through other mechanisms like the serotonin system. This floods the body with “messages,” which will have different effects depending on where certain receptors are located.

If CB receptors in the lymphnodes are being activated as part of the immune response, the message could be telling the body to lower inflammatory responses, thus decreasing pain for inflammatory conditions (which is why CBD helps with pain modulation).

The bottom line is, there is a lot scientists have learned about cannabis and its effects since THC was first discovered in 1964, but we are just beginning to find out how cannabis affects the body long-term. Because each brain works a little differently, the strain of cannabis that may help you with anxiety could have a different effect on someone else. This could be because of the wide variety of THC:CBD ratios that exist in recreational cannabis today, or because of the other chemicals produced by cannabis, like terpenes (which give each strain its unique aroma or “flavor profile”)—but maybe there is some other reason we haven’t quite figured out yet.

So before you send your very curious mother to the dispensary down the block, keep in mind that not all endocannabinoid systems are made the same. 



2Mackie K (May 2008). “Cannabinoid receptors: where they are and what they do”. J. Neuroendocrinology. 20 Suppl 1: 10–4.

3Aizpurua-Olaizola O, Elezgarai I, Rico-Barrio I, Zarandona I, Etxebarria N, Usobiaga A (January 2017). “Targeting the endocannabinoid system: future therapeutic strategies”. Drug Discovery Today22 (1): 105–110. 



Related Posts