Sesquiterpenes are a class of primary terpenes that account for approximately 7% of the overall terpene makeup of a cannabis plant. They are secreted in the sticky resin glands of the cannabis plant. Sesquiterpene is found in fragrant, fresh oils from cannabis bud, and because terpenes also contain levels of THC and CBD, these terpenes can bind to receptors in the brain and provide various medicinal benefits.

Sesquiterpenes act as a pheromone on the plant with a strong odor to repel harmful insects and attract pollinating insects. Sesquiterpenes differ from other cannabis terpenes because it contains one additional isoprene unit to create a 15-carbon structure; this makes sesquiterpenes less volatile than monoterpenes.