Humulene is one of the predominant terpenes in Humulus lupulus, the common hops, from which it derives its name. As hops and cannabis are plant cousins, it should come as no surprise that humulene is also one of the most common terpenes in cannabis.
What is Humulene?
Like beta-caryophyllene, alpha-humulene (or humulene) is a sesquiterpene, but it does not have the cyclobutane ring which makes caryophyllene stand out from other terpenes. Due to how frequently they are found together, in the past humulene was referred to as alpha-caryophyllene, but it is a substantially different terpene with its own medical effects. While beta-caryophyllene has been identified as a dietary cannabinoid, humulene has so far not been given that same status.
As the core ingredient in heavily hopped beers, like India Pale Ales, hops is usually described as having a bitter or “hoppy” flavor, which isn’t terribly helpful for anyone who hasn’t had an IPA. What is meant by bitter and hoppy is that the flavor is herbal, woody, or spicy, similar to the scents and flavors of the ginseng, sage, and cannabis plants where it also is commonly found.
It is important to note, that despite humulene (a terpene) having a very similar name to “humulone,” they are very different chemicals, and humulone is not a terpene but actually a form of lupulic acid found in hops. If you are researching studies on humulene you should be certain that the studies you are looking at are on humulene and not humulone.
The Hops Connection
Despite IPAs having “India” in their name, they were first brewed in England and originally called barleywine, the name became IPA when the British Indian army began to import it to India. While today, barleywine is a distinctly different style of beer with a higher alcohol content and sweeter flavor than most IPAs, what they have in common is a huge amount of hops, thus, humulene. Some of the original IPAs were brewed with “up to 10 pounds [of hops] per barrel.” The main reason for hops in beer is that it acts as a preservative, and as the main terpene in hops (up to 52% of the terpenes), humulene plays a huge part in those effects. In addition to having a high amount of humulene, most hops cultivars also have a significant amount of caryophyllene and myrcene. Like cannabis, there can be a wide range of flavors for different types of hops, from the sweet citrus Citra hops, to bitter cultivars like Chinook.
Given the strong genetic links between hops and cannabis, the overlap in terpenes shouldn’t be a shocker. The similarities go even deeper than that, as both cannabis and hops have resinous glands (either trichomes in cannabis, or lupulin glands in hops). This explains why many beer brewers and top craft breweries have been working on creating cannabis-infused beer, either with just terpenes, or in some cases cannabinoids as well.
Humulene in Cannabis
Despite humulene being one of the major terpenes in cannabis, the overall percentage can be quite low. In one older study, researchers found that just 0.7-6.7% of the terpenes in cannabis samples was humulene. In a 2018 study, the percentage of humulene was found to be as low as 11% to potentially as high as 27%, significantly more than in previous research.
Generally speaking, plants have terpenes because they offer some kind of defense or benefit to the plant, and humulene is no exception. Multiple studies have shown humulene to have insecticidal effects in a variety of plants, including “paralysis and muscle contractions … which indicates neurotoxic effects,” and it displays a “deterrent effect” against the yellow fever mosquito. Presumably, humulene plays a similar role in cannabis and hops, fending off predatory insects.
Medical Effects Of Humulene
Pain is one of the major conditions people turn to cannabis for, and humulene is one of the chemicals that plays a role in those pain relieving effects. Research has shown it to be an “effective analgesic when taken topically, orally, or by aerosol.” Multiple studies have found humulene to possess anti-inflammatory properties when taken topically, orally, and by aerosol. In one study, humulene was found to have anti-inflammatory effects comparable to the drug dexamethasone.
Just like humulene can protect plants from insects, it can help protect your body from bacteria. Despite humulene being a relatively minor constituent of balsam fir oil, it was found to be one of three terpenes in that oil with an effect against Staphylococcus aureus bacteria. In a 2020 study on humulene researchers noted it was also effective against enterotoxigenic Bacteroides fragilis, which can cause inflammatory bowel disease and colorectal cancer.
Beyond helping prevent a potential cause of colorectal cancer, humulene has demonstrated anti-cancer properties for a range of other cancers. In another study looking at balsam fir oil, humulene was observed to have dose-dependent antitumor effects through multiple mechanisms of action. A different study on humulene and cancer found its antiproliferative activities to be “significant,” and also that it possessed no binding properties for the CB2 receptor. Finally, caryophyllene has been shown to “significantly increase the anticancer activity of alpha-humulene.”
A Quick Hit
Humulene is one of the main terpenes found in both cannabis and hops, giving them a woody, spicy, or herbal flavor. In addition to giving IPAs their characteristic flavor, humulene has a number of medical benefits including antibacterial and anticancer properties.
