THC or CBD?

By Kimberly Kirchner, Herbalist contributor

To the inexperienced buyer, a dispensary menu can read like a chemistry textbook, full of scientific names and long lists of percentages. Two terms in particular get tossed around as proof of a product’s potency and medicinal value: THC and CBD. Understanding these two substances can help users find exactly what they’re looking for in their cannabis experience.

THC and CBD are cannabinoids, chemical compounds that interact with cannabinoid receptors throughout the body to alter transmissions within the brain, which in turn trigger the mental and physical effects of cannabis. Thanks to slightly different chemical structures, however, THC and CBD interact differently with these receptors.

THC (short for tetrahydrocannabinol) is the most abundant cannabinoid in marijuana, and the one responsible for its psychoactive effects. Found exclusively in the female cannabis plant, it works predominantly in the brain to produce a feeling of euphoria, or “high,” popular with recreational users. It’s also been associated with medicinal uses, showing promise as a treatment for anxiety, chronic pain, loss of appetite and nausea.

CBD, or cannabidiol, is the second-most concentrated cannabinoid in the cannabis plant, and is popular with medicinal cannabis users for several reasons. First, CBD is not psychoactive and does not produce a euphoric high like THC. Second, CBD is found in both marijuana and hemp (cannabis with no more than trace amounts of THC) plants. Hemp and its extracts, while still illegal in many places, are less tightly regulated than marijuana because they aren’t psychoactive.

Cannabidiol proponents suggest CBD is responsible for much of cannabis’ impact outside the brain, especially in the immune and nervous systems. In addition to its mitigating effect on pain, anxiety and inflammation, CBD has shown promising results as a treatment for some forms of epilepsy. In 2018, an orally administered CBD solution under the commercial name Epidiolex was approved by the Food and Drug Administration to treat two rare forms of childhood epilepsy.

CBD can have benefits for recreational users, as well, especially those who are sensitive to THC. Evidence suggests that CBD molecules might get between THC and the body's cannabinoid receptors, effectively muting THC’s effects. Depending on the ratio of the two chemicals, this can result in a milder high and fewer unpleasant side effects, such as increased heart rate, dry mouth and red eyes.

To grossly oversimplify, THC is the Phish-blasting, prank-pulling party animal of the cannabis plant; CBD is the yoga enthusiast with a penchant for meditation and clean eating. In more nuanced terms, we’ve been able to roughly define each compound — THC works on the brain, CBD on the body — but future research will give us a better understanding of what they do, why they do it and how they interact with each other.