What is Tetrahydrocannabinol? – THC Definition

Tetrahydrocannabinol — most commonly known as THC or delta 9 THC — is a chemical in the cannabis plant (the marijuana plant). It has psychoactive properties and is responsible for the high effect users get from smoking or ingesting marijuana. It’s used for both recreational and medicinal purposes, including chronic pain, anxiety, and appetite disorder management.

When THC enters the body, it attaches to cannabinoid receptors in the brain responsible for balance, memory, the perception of time, and emotions like joy and gratification. Once attached to THC, these receptors release dopamine, which creates feelings of euphoria. This affects users’ coordination, memory, and mood, and often results in intoxication (being high).

Because it’s only one of many chemicals in the cannabis plant, THC isn’t in every marijuana product. For example, cannabidiol (CBD) is another individual chemical compound in marijuana, so it doesn’t contain THC and is nonpsychoactive.