What is HHCP (hexahydrocannabiphorol)?

HHCP (hexahydrocannabiphorol) is a semi-synthetic cannabinoid related to HHC, made in laboratories and sold as an intoxicating alternative to THC. It has a seven-carbon side chain instead of the five carbons of HHC and THC. Its effects in people have hardly been studied, poisonings have been reported in Europe, and in the UK the government has said it will make HHCP a Class B drug.

What is HHCP?

HHCP stands for hexahydrocannabiphorol. It belongs to the semi-synthetic cannabinoids: compounds related to THC that are made by chemically changing other cannabinoids, often starting from hemp-derived CBD. The best known of them is HHC, which appeared on the drug market in 2021 (Ujváry 2024). HHCP has the same ring structure as HHC, but its side chain has seven carbon atoms (heptyl) instead of five (pentyl) (Lindbom 2025).

The name "-phorol" is the same as in THCP, the seven-carbon version of THC. Our guide synthetic vs natural cannabinoids explains how these lab-made compounds differ from the cannabinoids that hemp makes itself.

How is HHCP made?

Sellers often claim HHCP is made from CBD, but CBD has a five-carbon side chain and HHCP has seven, so it cannot simply be converted. When Swiss researchers analysed an HHCP sample, they isolated six different substances, including several HHCP isomers and so-called abnormal cannabinoids. They concluded that the sample had been produced purely synthetically (Schirmer 2025).

The same study describes how HHCP spread: after Switzerland banned HHC in March 2023, other semi-synthetic cannabinoids appeared on the Swiss grey market, HHCP most prominently. In October 2023, Switzerland introduced a class-wide ban on this group of compounds (Schirmer 2025).

What are HHCP's effects?

There are no controlled studies of HHCP's effects in people. Swiss researchers note that anecdotal reports from recreational users suggest potent THC-like effects (Schirmer 2025). What is known comes from metabolism studies and poisoning reports:

• Metabolism: in human liver cells, HHCP was broken down much like HHC, mainly by adding a hydroxyl group and then forming a carboxylic acid. Its acetate, HHCP-O, was quickly converted to HHCP (Lindbom 2025).
• Poisonings: the Czech Toxicology Information Centre analysed 196 cases of HHC and HHCP exposure reported between May 2022 and April 2024. Symptoms were mainly neurological, cardiovascular and gastrointestinal. A doctor had to intervene in 87.8% of cases, 6.1% were severe, and 19% involved children under 15. Almost all patients recovered, and no deaths were reported (Čečrle 2025).

Products sold as HHCP may also contain by-products of synthesis that nobody has tested for safety (Schirmer 2025).

Is HHCP legal in the UK?

Not for sale as a psychoactive product. The Advisory Council on the Misuse of Drugs (ACMD) reported in 2025 that HHC, HHCO, HHCP and THCA had been found in the UK, and that HHC and related hexahydro compounds were not captured by the UK's existing generic definition of cannabinoids. It noted that psychoactive examples are covered by the Psychoactive Substances Act 2016. On 20 August 2025 the government accepted the ACMD's recommendation to list HHCP, HHC and several related compounds as Class B drugs and said it would implement this when parliamentary time allows (ACMD 2025).

THC itself is controlled as a Class B drug, while pure CBD is not (Home Office 2024). Our guide is CBD legal in the UK? covers the rules for CBD products.

Is HHCP the same as CBD?

No. CBD is made by the hemp plant and does not cause a high. HHCP is made in a laboratory, has a longer side chain and is sold for its intoxicating effect. Hemp-derived CBD products and HHCP products are often sold side by side online, which is why it pays to check the label and the certificate of analysis. For an overview of which compounds intoxicate, see which cannabinoids produce a psychoactive effect?