Alpha-humulene (α-humulene), also known as α-caryophyllene, is a naturally occurring monocyclic sesquiterpene hydrocarbon prevalent in the essential oils of hops (Humulus lupulus), cannabis sativa, sage, and ginseng. It imparts earthy, woody, and spicy aromatic notes and plays a significant role in the flavor and aroma profiles of beer and various spices. Research indicates potential pharmacological activities including anti-inflammatory effects via PPAR-α agonism, analgesic properties, and appetite suppression. As a key terpene in plant defense and secondary metabolism, it contributes to the chemical ecology of aromatic species. It is widely used in perfumery, flavoring, and investigated for therapeutic applications in inflammatory disorders.