What is HHC? An Evidence-Based Guide

By | Updated on May 31, 2024

Medically reviewed by
Kimberly Langdon

Evidence Based 7

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Key takeaways:

  • Hexahydrocannabinol (HHC) is a synthetic form of THC made by adding hydrogen. It has similar but less potent psychoactive effects compared to regular (delta-9) THC.
  • Although there’s a lack of research, user reports suggest that HHC has similar potential side effects to THC, including anxiety and impaired memory. The bigger safety concern is removing any potential contaminants after HHC is made.
  • When shopping for HHC products, make sure to buy from reputable brands backed by third-party test reports for both potency and contaminants to ensure a safe and accurate product.

While CBD remains the star of the hemp cannabinoid industry, “alternative” cannabinoids like delta-8 THC, delta-10-THC, and THC-O have grown popular.

One of the newest additions to this list is hexahydrocannabinol (HHC), a psychoactive cannabinoid made by hydrogenating THC. Unfortunately, evidence-based information about HHC is scarce.

That’s why I contacted Kentucky’s KCA Labs, one of the only hemp testing labs in the country familiar with HHC, for more info.

What is HHC? Is it safe? How can you make sure you’re buying a legitimate and safe product? Here’s a science-backed look at this new cannabinoid.

What is HHC?

Hexahydrocannabinol (HHC) is a synthetic cannabinoid made in a lab through a process called hydrogenation. HHC is closely related to cannabinol (CBN) and tetrahydrocannabinol (THC), two naturally occurring cannabinoids.

The name hexahydrocannabinol means that six hydrogen atoms (“hexahydro”) have been added to a cannabinol molecule (two more than THC).

Although minuscule amounts of natural HHC-like compounds have been discovered in cannabis plants, they are still chemically different from HHC.

Did you know? Some experts use the abbreviation HHC to refer to related compounds such as 9-beta-hydroxyhexahydrocannabinol. Experts over at KCA labs argue that the term should be reserved specifically for hexahydrocannabinol.

What are the Effects of HHC?

HHC interacts with the brain’s cannabinoid receptors, causing effects similar to delta-9 THC. That means HHC can get you high and cause effects like euphoria, sleepiness, dry mouth, and hunger.

There isn’t any research to tell us precisely how strong HHC is. But user reports suggest that it’s less potent than delta-9 THC, the most common form of THC in cannabis, and similar to the mellower effects of delta-8 THC.

That lines up with my experience taking HHC gummies, which felt similar to delta-8 ones and caused effects like increased appetite, euphoria, dry mouth, and sleepiness.

How is HHC Made?

HHC is made through a two step process:

  1. First, pure cannabidiol (CBD) derived from hemp plants is transformed into a mixture of delta-8 and delta-9 THC through a chemical reaction.
  2. Next, the mixture is hydrogenated to turn the THC into HHC.

The hydrogenation process involves replacing the double bond in delta-9 or delta-8 THC with hydrogen molecules.

It’s done by adding a metal catalyst like palladium to catalyze the addition of a hydrogen molecule across the double bond in the cyclohexenyl ring of THC, which breaks the bond (see illustration below).

Hydrogenation requires a skilled chemist because there’s a real risk of explosion when handling hydrogen gas. Chemist Roger Adams was reportedly the first to synthesize HHC in the 1940s.

Hydrogenation is also widely used in the food industry to turn vegetable oils into margarine and other solid-fat products.

HHC Isomers

It’s important to note that the hydrogenation process creates two HHC isomers — molecules with the same formula but a slightly different arrangement of atoms.

For HHC, these isomers are called (6aR,9R,10aR)-HHC or (9R)-HHC for short and (6aR,9S,10aR)-HHC or (9S)-HHC.

(9R)-HHC is reported to be about 20 times stronger than the (9S) isomer, which means that HHC products containing higher amounts of the 9R isomer can be expected to have greater psychoactive effects.

Most legitimate HHC products contain close to a 50/50 mix of the isomers, but it can differ depending on the relative abundance of delta-8-THC and delta-9-THC in the conversion materials obtained from CBD.

Is HHC Safe?

There’s little to no research on HHC, so we don’t know. Anecdotal user reports coupled with what we know about the effects of other psychoactive cannabinoids suggest that HHC is about as safe as THC.

However, the effects of ingesting hydrogenated substances from the conversion mixture are unknown.

There haven’t been any reports of serious side effects from HHC consumption. However, we can assume that it may cause anxiety, slowed reaction time, impaired memory, and other common side effects associated with THC.

Additionally, the company Colorado Chromatography, which synthesizes HHC through a patent-pending process, recently released the results of four preclinical safety studies.

The researchers concluded that a mixture of the two HHC isomers was not mutagenic, didn’t cause cardiac safety issues, and was not toxic to human liver cells. However, it may be harmful to lung cells. Of course, proper clinical trials are needed before we can say anything definitive.

HHC Contamination

Another safety concern with HHC is contamination. Although the process used to make HHC has a low potential to produce toxic residues, the first step of the process, which turns CBD into THC, can produce harmful compounds.

That means unscrupulous or inexperienced manufacturers can do an inadequate job of removing harmful chemicals from finished HHC products.

That’s one reason why third-party contaminant testing by a reputable, experienced, accredited lab is crucial when buying HHC products.

Is HHC Legal?

The truth is that nobody knows. Technically speaking, hemp-derived HHC is legal. That means starting with extracting pure cannabidiol (CBD) from hemp, converting it into THC, and then hydrogenating it into HHC.

According to the 2018 Farm Bill, hemp and hemp derivatives are legal cannabis products that can contain no more than 0.3% delta-9 THC.

But there are many questions, such as whether HHC counts as a synthetic cannabinoid or a form of THC, which could make it illegal federally or at least in certain states.

In that sense, the legal status of HHC is quite similar to that of delta-8 THC, another relatively new cannabinoid that is psychoactive but is “technically” legal because it’s derived from hemp.

The bottom line is that the current laws leave a legal gray area, allowing companies to sell “alternative” cannabinoids like delta-8, delta-10, THC-O, and HHC. Until this is addressed through legislation, we can expect more synthetic THC products to appear on the market.

Does HHC Show Up on a Drug Test?

Drug tests look for the metabolites of THC. Since HHC has a similar structure, it may produce similar metabolites, which means it could show up on a drug test. So yes, you can test positive for THC if you use HHC products.

What do HHC Products Contain?

Another issue with HHC products is that they don’t necessarily contain just HHC. For one thing, they may contain other cannabinoid and non-cannabinoid substances that resulted from the conversion CBD into THC and were hydrogenated during the synthesis of HHC.

Some scam companies also market products labeled as HHC but that have no HHC at all and instead contain other cannabinoids like delta-8-THC since their effects are similar.

Finally, the ratio of the two HHC isomers varies between products and brands, which means the potency and effects will be different. These factors highlight the importance of proper third-party testing to verify exactly what you’re getting.

Who Makes HHC?

It’s a common practice in many industries for companies to source a product from a single or several manufacturers and put their labels on it. The same thing may be happening with HHC since it requires experienced chemists and a well-equipped laboratory.

Although I couldn’t find many details, I suspect that a few companies, like Colorado Chromatography, are making the purified HHC, which is then sold to HHC vendors who formulate their own products.

HHC Third-Party Testing

If you’ve read any of my articles, you’ll know I’m big on third-party testing.

I always recommend that people only buy CBD, delta-8-THC, and any other hemp cannabinoid product with publicly available, up-to-date potency and contaminant third-party test reports done by a reputable lab.

That’s even more important for HHC because it’s a relatively new product and requires advanced chemical knowledge to prepare and purify. An added problem with HHC is that few testing labs know how to identify it.

At this time, there are only a handful of hemp & cannabis testing labs that you can trust to provide correct and accurate test results for HHC.

The best one is Kentucky’s KCA Labs, the same lab that gave me information to help write this article. Other reputable labs trusted by CBD industry insiders are Gobi Labs, New Bloom Labs, and Columbia Laboratories.

KCA developed methods to identify and measure the two isomers of HHC and released several scientific papers (that I discussed earlier) about these substances. It’s also one of the only labs that provide accurate and reliable test results for delta-8-THC and delta-10 THC.

KCA labs third-party lab test report for HHC
An example of a legitimate HHC third-party lab test report done by KCA Labs.

As you can see in the above screenshot, this lab result shows exactly how much HHC (in both its isomer forms, 9R and 9S) is present in the product.

The Best HHC Brands

You have to be careful when shopping for HHC. Although many companies sell HHC vape pens, carts, gummies, and more, only a few are trustworthy and send their products to the reputable labs I mentioned earlier. There are many scam vendors and low-quality products.

If you’re completely deadset on trying out HHC, I recommend exercising caution and doing plenty of research before buying anything.

Right now, the best options are:

  • Summit, the sister company of the reputable CBD brand R&R
  • TreHouse, a brand operated by CBDfx, another trustworthy CBD company
  • Purekana, an established CBD vendor


summit hhc gummies


HHC Potency25 mg
Gummy Count20
Total HHC500 mg
Cost per mg HHC$0.10
Third-Party TestsView report


  • Comprehensive third-party testing
  • Free shipping
  • Quality ingredients


  • Only gummies available

The best HHC product I’ve come across is the gummies from Summit, the sister brand of reputable CBD company R&R. I’m a big fan of this brand because it provides detailed test results from a top-tier lab (Columbia Laboratories).

It also uses high-quality ingredients like tapioca syrup and pectin and only natural flavorings and colors.


trehouse hhc disposable vape pen


Potency20-50 mg
Gummy Count20
Total HHC500-1900 mg
Cost per mg HHC$0.02-0.08
Product Types3
Third-Party TestsView report


  • Low prices
  • Three product types
  • Multiple flavors
  • Potency third-party tests


  • Some products don’t have contaminant tests

TREHouse is a brand by the same people behind CBDfx, one of the most popular CBD companies out there. It specializes in intoxicating hemp-derived cannabinoids, including delta-8, delta-9, delta-10, and HHC.

TREHouse sells HHC gummies, cookies, and disposable vape pens in multiple flavors and cannabinoid formulas. It also has some of the lowest prices for HHC products I’ve seen. The vape pens are especially cheap.

Trehouse’s products are tested by the previously-mentioned KCA Labs and Gobi Labs, which is great to see.


purekana hhc gummies


HHC Potency25 mg/90%
Gummy Count/Volume20/1 gram
Total HHC500-900 mg
Cost per mg HHC$0.04-0.08
Third-Party TestsView report


  • Comprehensive third-party testing
  • Free shipping
  • Three product types


  • Not all tests are done by KCA Labs

Founded in 2017, Arizona’s PureKana is an established CBD company that also offers delta-8, HHC, and TCH-O products. It sells 25 mg HHC gummies, 900 mg vape cartridges, and 900 mg disposable vapes.

PureKana uses KCA Labs to test some of its HHC products. Other tests are done by Kaycha Labs, another reputable lab.

My experience: I took a piece near bedtime alongside peanut butter for improved absorption. I felt relaxed with a minor buzz and dry mouth about an hour and a half later. About 10 minutes later I had to get into bed because I felt quite sleepy. I fell asleep quickly but did wake up at 6 am for a bit and dreamed less.

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