Used for centuries as a source of bitter principles in the brewing of beer, Hops (Humulus lupulus) has a long history of medicinal use as well. Native to North America and parts of Europe, it is the cone-like fruits (strobiles) with many resinous, glandular hairs that are used. Hops contain volatile oils, resinous bitter principles (humulone, lupulone etc.), flavonoid glycosides like rutin, tannins and phenolic acid among its identified active constituents. Some of the bitter resins have been implicated as antimicrobial, but hops are most often used medicinally for their sedative effects.

Traditional medicine has used hops as a sedative for centuries, while only recently has one of the possible components (dimethylvinylcarbinol), a volatile alcohol, been identified as having sedative effects. Hops will usually be found in products used as sedatives or sleep-aids, especially for children.