What is HHC? An Evidence-Based Guide (Dec. 2022)

By | last updated April 16, 2023

Medically reviewed by
Kimberly Langdon, MD

Evidence Based 7

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While CBD remains the star of the hemp cannabinoid industry, “alternative” cannabinoids such as delta-8 THC, delta-10-THC, and THC-O have grown popular in the last two years.

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

That’s why we reached out to Kentucky’s KCA Labs, one of the only hemp testing labs in the country familiar with HHC, who provided us with more information.

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 novel cannabinoid compound. Although minuscule amounts of HHC-like compounds have been discovered in cannabis plants, they are chemically different from HHC which is typically made in a laboratory by hydrogenating THC.

The name HHC highlights its chemical similarity to cannabinol (CBN) and tetrahydrocannabinol (THC), two naturally-occurring cannabinoids. In fact, HHC is made from THC by hydrogenation using hydrogen gas and a catalyst.

Tetrahydrocannabinol is named as such because it’s a derivative of cannabinol in which four hydrogen atoms have been added. Hydrogenation of tetrahydrocannabinol adds two more hydrogen atoms so the resulting substance is a hexahydrocannabinol.

Since “tetrahydro” indicates four hydrogen atoms, adding two more makes it “hexahydro,” which means six more hydrogen atoms than cannabinol.

Keep in mind that some people (including researchers) 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 those produced by delta-9 THC. That means that HHC can cause euphoria, sleepiness, and reduce inflammation and pain, among other effects depending on the dose administered.

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 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 from THC through a chemical process called hydrogenation, where molecules of hydrogen replace a double bond in delta-9 or delta-8 THC. Hydrogenation is also widely used to turn vegetable oils into margarine and other solid fat products.

Chemist Roger Adams was reportedly the first to synthesize HHC back in the 1940s.

The hydrogenation process involves 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 red circles below).

Hydrogenation requires a skilled chemist because there’s a real risk of explosion when handling hydrogen gas. Another important caveat is that the THC used to make HHC is usually made by converting pure CBD into THC — the same process used to make delta-8 THC.

That’s because hemp is federally legal and contains high amounts of CBD but little THC. Hydrogenation of CBD directly without conversion to CBD produces a different substance that is not HHC.

HHC Isomers

It’s important to note that the hydrogenation process creates two HHC isomers — molecules that have the same formula but a slightly different configuration 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. These isomers are not mirror images of each other and are therefore separable by standard chromatographic methods used by cannabis/hemp testing labs.

(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 abundances 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 simply don’t know. Having said that, anecdotal user reports coupled with what we know about the effects of other cannabinoids suggest that HHC has a similar safety profile to 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, although 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 their mixture of two HHC isomers was not mutagenic, didn’t cause cardiac safety issues, and was not toxic to human liver cells, although it may be harmful to lung cells. Of course, proper clinical trials are needed before we can say anything definitive.

But another safety concern with HHC is contamination. Although the process used to make HHC has a low potential to produce toxic residues, the synthesis of THC from CBD requires more care. 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 novel cannabinoid products to appear on the market.

Does HHC Show Up on a Drug Test?

Drug tests look for the metabolites of THC. HHC does not produce the same metabolites as THC but it may produce similar metabolites which are not differentiated from THC metabolites, which means it could show up on a drug test.

What do HHC Products Contain?

Another issue with HHC products is that they don’t necessarily contain HHC. For one thing, they may contain other cannabinoid and non-cannabinoid substances that were in the conversion product and then 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 isomers varies between products and brands, which means the potency and effects will be different from one to the other based. All of 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 label on it. The same thing may be happening with HHC since it requires experienced chemists and a well-equipped laboratory.

Although we couldn’t find any specifics, we suspect that a small number of companies like Colorado Chromatography are making the purified HHC which is then sold to HHC vendors who use it to formulate their own products.

HHC Third-Party Testing

If you’ve read any of our articles, you’ll know that we’re big on third-party testing.

We 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 produced by a reputable lab.

That’s even more important for HHC because it’s a hot new product and requires advanced chemical knowledge to prepare and purify. An added problem with HHC is that very few testing labs know how to identify and quantify 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 we linked to 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 you exactly how much HHC (in both of 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 are selling HHC vape pens, carts, gummies, and more, only a few are trustworthy and send their products to the reputable labs we mentioned earlier. There are many scam vendors and low-quality products.

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

Right now, the three best options are:

  • Summit, the sister company of reputable CBD brand R&R
  • PureKana, another established CBD company
  • TreHouse, a brand operated by CBDfx, another trusted CBD company


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 are 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 reputable lab (Columbia Laboratories). It also uses high-quality ingredients like tapioca syrup and pectin, and only natural flavoring and colors.


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 at reasonable prices.

PureKana uses KCA Labs to test some of its HHC products. Other tests are done by Kaycha Labs, another reputable lab. PureKana has over 9,000 customer reviews with an average 4 out of 5 stars on the independent review website Trustpilot, highlighting its reliable reputation.

My experience: I tried the HHC gummies, taking one 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.


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 new brand by the makers of 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 we’ve seen. The vape pens are especially cheap, containing 1900 mg HHC at only about 2 cents per mg.

Only some of Trehouse’s products are tested by KCA labs. But it does also use Gobi Labs, another testing lab considered reputable for HHC testing.

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