Ask Dr. Leigh: what is HHC?

what is hhc

Using cannabis can have a big impact on your physical and mental health—for better, and once in a while, for worse. That’s why it’s important to consult a healthcare provider before experimenting.

Here at GreenState, cannabis clinician Dr. Leigh Vinocur is here to answer your questions on healthy living with cannabis.

RELATED: Ask Dr. Leigh: can cannabis help dementia patients?

Editor’s Note: The answer to this question is meant to supplement, not replace, advice, diagnoses, and treatment from a healthcare provider.  Always consult a medical professional when using cannabis for medicinal purposes, and do not disregard the advice of your healthcare provider because of anything you may read in this article. 

Q) I have seen vape shops offering HHC; what is that? 

HHC is the abbreviation for Hexahydrocannabinol. It’s a relatively “new” compound in the cannabis marketplace, generating significant interest and curiosity. It is now being synthesized from other cannabinoids, which is why it is now characterized as a semi-synthetic compound. 

HHC was actually first synthesized by the prestigious chemist Roger Adams in the 1940s while at the University of Illinois-Champaign Urbana. He used the natural THC from Cannabis Sativa.

However, the products today on the shelves seen in vape shops are mostly synthesized from hemp-based compounds such as CBD. It is done by adding hydrogen atoms so that HHC has no double bonds in the cyclohexyl ring, causing it to be hydrogenated, much like the fats used to create margarine. This not only makes HHC more stable and less susceptible to oxidation but also slightly alters its effects compared to THC. It is believed to be less intoxicating than THC but obviously more intoxicating than the original compound, CBD.  

What are the effects of HHC on the body?

There is not a lot of data in the medical research on this compound. Some studies have shown it does interact with our endocannabinoid system, so it will have physiological effects.  A study that surveyed users of HHC reported effects such as mild intoxication and altered perception, along with some potential medicinal benefits like pain relief and reduced anxiety. The research corroborated reports that its effects are milder than those of THC.  Of note, these effects can vary widely in individuals, and they depend on the dosing and purity of the product—which brings up the very important issue of safety. 

How safe is HHC? 

There is very limited research regarding the safety profile of HHC. In fact, many hemp-derived cannabinoids (including HHC) are not subject to stricter cannabis regulations seen in legal medical and adult-use markets in states that require third-party testing to ensure proper purity and potency. These laws ensure proper labeling and dosages of the compounds present and testing for dangerous contaminants such as heavy metals, molds, and bacteria. 

According to the FDA, there is also the risk of dangerous residual solvents and by-products that can be found in these compounds, such as HHC and Delta-8-THC, after their synthesis from CBD. And for those people who feel they can use these intoxicating compounds such as HHC and skirt detection during cannabis drug testing, they may, in fact, be wrong. A study examining the analytical toxicology testing found that HHC could be detected after qualitative analysis. This then begs the question of legality. 

Is it legal? 

That is not a clear-cut issue despite it being a hemp-derived product that was legalized with the 2018 Farm Bill.  There is no federal clarity on this yet. However, looking at Delta-8-THC as an example of a newer hemp-based semi-synthetic, the DEA is now considering its legality in its Interim Final Rule (IFR).  

Additionally, for both Delta-8-THC and HHC, as well as any new synthetic cannabis compounds that might be developed in the future, the federal government has already enacted a law called the Federal Analogue Act. It states that any substance or drug sold for human consumption that has analogous biological effects and is chemically similar to a controlled substance will also be treated as a Scheduled I controlled substance and illegal.  

While the feds are figuring this out, some states have taken matters into their own hands. Currently, with respect to the other semi-synthetic compounds, such as Delta-8-THC, 16 states are regulating its sales. 13 states have banned its sale either by law or administrative rule. However, the issue has not been determined yet for HHC by either the federal or state governments.  

In conclusion, as a physician, in my opinion, using a semi-synthetic cannabinoid like HHC should be approached with caution. Without the protective guardrails of testing for standardization and purity, it can pose a safety hazard. Additionally, the lack of meaningful clinical research on short- and long-term effects and safety and the murky legal landscape of these products should not be used therapeutically.  

Got cannabis questions? Ask Doctor Leigh. Send your questions to GreenState’s Editor at and keep an eye out for new answers from Dr. Leigh Vinocur every month.

Dr. Leigh Vinocur is a board-certified emergency physician who also has a cannabis consulting practice for patients and industry. She is a member of the Society of Cannabis Clinicians and a graduate of the inaugural class, with the first Master of Science in the country in Medical Cannabis Science and Therapeutics from the University of Maryland School of Pharmacy.

The response to this question was not written or edited by Hearst. The author is solely responsible for the content.