BY BEN THOMAS | Image by Alexander Grey
The past few years have seen an explosion in “new” cannabinoids synthesized from CBD. You’ve probably gotten used to seeing these synthetic delta-8 and delta-10 products on your local dispensary’s shelves, along with the classic delta-9-THC—but lately you may have heard about a much more unusual cannabinoid: Hexahydrocannabinol, or HHC.
Google doesn’t seem to know much more about HHC than budtenders do. Some articles say it produces a high almost as powerful as delta-9’s, while others insist it’s only mildly psychoactive. Meanwhile, some vendors assert that HHC can evade drug tests that pick up other cannabinoids—though evidence for this claim is shaky at best.
In fact, hard scientific data about HHC is remarkably tough to come by. Chemists know this cannabinoid occurs naturally in cannabis plants, but only in small concentrations—and HHC products are so new to the market that no scientific studies have yet delved into the molecule’s effects in detail. In other words, we know what HHC is and how to make it, but hardly anything about what it does to the human mind and body.
This could be a significant concern for cannabis consumers—especially since many synthetic cannabinoid products have been shown to contain as many as 30 unidentified contaminants in addition to their (often poorly understood) active ingredients. So before you pick up an HHC edible or vape cartridge, let’s get the facts straight, and find out what we really know.
HHC is an acronym for hexahydrocannabinol, a cannabinoid that occurs in extremely low concentrations in natural cannabis plants. If this molecule’s full name reminds you of tetrahydrocannabinol (THC), that’s no coincidence: HHC is essentially a modified version of the delta-9-THC molecule.
Take a close look at THC and HHC molecules side-by-side, and you’ll notice a tiny difference in the hexagon closest to the top. That hexagon represents a cyclohexyl ring, and that little line just inside its top-right side means two hydrogen atoms share a double bond at that location. In fact, all isomers of THC, including delta-8 and delta-9, have a double bond there.
In an HHC molecule, on the other hand, that double bond has been replaced by two additional hydrogen atoms, through a process called hydrogenation. These two extra hydrogen atoms change the molecule’s name from tetra-hydrocannabinol, from the Greek prefix for “four,” tetra, to hexa-hydrocannabinol, from the Greek prefix for “six,” hexa.
HHC’s two additional hydrogen atoms weaken its ability to bind to cannabinoid receptors in the ways THC isomers like delta-8 and delta-9 do. This suggests that HHC should be a lot less psychoactive than delta-9-THC, and somewhat less psychoactive than delta-8, too. However, since scientific research on HHC’s effects is almost nonexistent, all we have to go on (for now) are anecdotes from anonymous users—and since everyone’s neurochemistry is unique, it’s hard to know what to make of these vague and contradictory trip reports.
In a Reddit thread on HHC experiences, for example, one reviewer describes “a fuzziness and a softness that pulses lightly through the body, and… a mental cloudiness… akin to delta-9.” Another user, meanwhile, says HHC’s effects are similar to those of delta-9-THC, but “with more euphoria and floaty headspace; less intense but smoother overall.” However, other users insist that HHC “does nothing” for them psychoactively, while still others complain that it gives them headaches they don’t get from THC.
It’s worth remembering that these are all just personal anecdotes, not scientific findings—in fact, it’s entirely possible that some of these anonymous “positive reviews” are coming from manufacturers, vendors and publicists who want to hype HHC products through organic marketing. Until we’ve got more objective scientific research on HHC, the truth is that we just don’t have enough data to reach a clear conclusion about how this chemical affects people.
Since HHC occurs in such low concentrations in cannabis plants, products sold under the name “HHC” aren’t the natural molecule; they’re synthetic substitutes generated from CBD in laboratories. This means that, despite what vendors may claim when they try to sell you HHC, these products occupy a sketchy gray area, both legally and in terms of safety.
Manufacturers insist that HHC is perfectly legal, due to a supposed loophole in Congress’s 2018 Farm Bill, which states that any Cannabis sativa plant containing less than 0.3 percent THC by weight is not illegal “marijuana,” but legal “hemp.” According to vendors, this means that all chemicals synthesized from hemp plants are legal, too—which is basically like saying that if Sudafed is legal, then so is methamphetamine. Not a super convincing argument.
More worryingly, an ongoing survey by ProVerde Labs has found potentially toxic chemical contaminants in every synthetic cannabinoid on the market right now. Most include additional THC isomers that don’t exist in natural cannabis—while others have been found to contain as many as 30 unidentified chemicals. “Every sample these vendors send me seems to be more contaminated than the last,” says Dr. Christopher Hudalla, ProVerde’s president and chief scientific officer. That’s good reason for customers to think twice before buying any synthetic cannabinoid, which Hudalla compares to “bathtub gin” on the danger scale.
One of HHC’s biggest selling points, according to manufacturers, is that it can supposedly evade drug tests. They claim that HHC is less likely to metabolize into 11-Hydroxy-THC—the THC metabolite that sticks around longest in the body, and the one that most drug screenings look for—than either delta-8 or delta-9-THC is.
However, even hardcore HHC supporters admit there’s no scientific evidence for this claim. And since even a tiny amount of 11-Hydroxy-THC can be detected in hair and urine for 30 days or more after imbibing, the smartest move is to avoid HHC (along with all other cannabinoids) if you’re aiming to pass a weed screening within the next few weeks.
HHC is so new to the cannabis market that no peer-reviewed scientific study has yet examined its effects on humans, as of fall 2022. This means all the info we have on HHC is coming from anecdotal trip reports, subjective customer reviews, and manufacturers’ publicity hype.
Until researchers have examined HHC’s effects across a sizable group of people, and contrasted those effects with those of a control group dosed with other cannabinoids (or with no cannabinoids at all), we’re really just taking strangers’ word that HHC does what they say.
One way to find out could be to try HHC for yourself—but given the safety risks of synthetic cannabinoids, a smarter idea might just be to stick with products made from natural cannabis.
Ben Thomas is a journalist and novelist who's lived in 40+ countries. He runs the publishing company House Blackwood, and produces the podcast Horrifying Tales of Wonder! Follow him on Twitter at @writingben.