Humulene

Humulene, also called alpha-humulene or alpha-caryophyllene, was first identified in hops (Humulus lupulus), which gave it its name, and it contributes to the "hoppy" aroma of many beers. Leafly describes it as an herbal terpene. It is an isomer of beta-caryophyllene and the two usually occur together; Wikipedia lists sage, spearmint, ginseng species and plants of the ginger family among other sources. In Leafly's cannabis lab data it is almost always a minor terpene, appearing in the lower ranks of Critical Mass, Chemdawg, Sour Diesel, Headband and Amnesia Haze.

A 2007 study in the European Journal of Pharmacology found that alpha-humulene isolated from Cordia verbenacea reduced several kinds of inflammation in mice and rats, with effects comparable to the steroid dexamethasone in those models. A 2021 Scientific Reports study found it produced cannabinoid-like behaviors in mice. A 2024 scoping review in Planta Medica, covering 340 articles, concluded that despite promising preclinical results there is a paucity of studies translating the research into patients, citing variable yields and poor bioavailability as barriers.

Boiling point: PubChem lists only a reduced-pressure value (about 99–100 °C at 3 mmHg), and the NIST Chemistry WebBook likewise gives only reduced-pressure data. We did not find a sourced boiling point at normal atmospheric pressure, and reduced-pressure figures should not be compared directly with the atmospheric values given for other terpenes.