The endocannabinoid system comprises a vast network of chemical signals and cellular receptors that are densely packed throughout our brains and bodies. The "cannabinoid" receptors in the brain — the CB1 receptors — outnumber many of the other receptor types on the brain. They act like traffic cops to control the levels and activity of most of the other neurotransmitters. This is how they regulate things: by immediate feedback, turning up or down the activity of whichever system needs to be adjusted, whether that is hunger, temperature, or alertness.

To stimulate these receptors, our bodies produce molecules called endocannabinoids, which have a structural similarity to molecules in the cannabis plant. The first endocannabinoid that was discovered was named anandamide after the Sanskrit word ananda for bliss. All of us have tiny cannabis-like molecules floating around in our brains. The cannabis plant, which humans have been using for about 5,000 years, essentially works its effect by hijacking this ancient cellular machinery.

Cannabinoids are a fundamental part of the cannabis plant. These naturally occurring chemical compounds contribute to the myriad effects cannabis consumers experience when they light up a joint, eat an edible, or drop a cannabis-infused tincture under their tongue.

THC and CBD are by far the best known cannabinoid acids produced by cannabis. These two cannabinoids occur in much higher concentrations than other cannabinoids present in the plant. Both THC and CBD are psychoactive cannabinoids, so they can alter nervous system function and temporarily change perception, mood, cognition, and behavior. THC is intoxicating and can get you high, while CBD does not. Both cannabinoids also boast a range of other physical and mental effects. These two major cannabinoids also form the basis for defining cannabis.

Terpenes, the aromatic compounds that determine the scent of many flowers and herbs, bestow cannabis with its distinctive odor and contribute to its flavor. Cannabis contains more than 150 types of terpenes. Although most terpenes are present in only trace amounts, the more prominent ones team together to give diverse cannabis strains their signature scent profiles.

Beyond providing cannabis with its unique bouquet of scents, terpenes also hold diverse functions in the plant and can produce a range of therapeutic and mood-altering effects in cannabis consumers. Most cannabis cultivars are dominant in either myrcene or caryophyllene. Myrcene, a terpene that’s also predominant in hops and lemongrass, has been described as delivering scent notes that are herbaceous, spicy, earthy, and musky. Caryophyllene, also known as beta-caryophyllene or β-caryophyllene, lends a spicy, peppery bite to some cannabis strains. Caryophyllene is also found in other plants such as cloves, rosemary, oregano, and black pepper.