THCP (tetrahydrocannabiphorol) is a cannabinoid with the same structure as THC but a longer, seven-carbon side chain, first identified in cannabis in 2019. In laboratory tests it bound to the CB1 receptor about 33 times more strongly than THC, and in mice it caused THC-like effects. It occurs only in trace amounts, there are no studies in people, and in the UK it falls under the controls on cannabinol derivatives.
Key facts
- Full name
- (−)-trans-Δ9-tetrahydrocannabiphorol (Δ9-THCP)
- Discovered
- 2019, by Citti and colleagues in Italy, in the medicinal cannabis variety FM2
- Structure
- Like THC, but with a heptyl (seven-carbon) side chain instead of a pentyl (five-carbon) one
- CB1 binding
- Ki 1.2 nM against 40 nM for THC in vitro, about 33 times stronger
- Amount in the plant
- About 29 µg/g in the FM2 extract, against 39 mg/g of THC
- Human studies
- None published as of October 2026
Prefer watching? This video covers the key points:
What is THCP?
THCP is one of the minor cannabinoids, compounds that occur in cannabis in much smaller amounts than THC and CBD. It is the seven-carbon "cousin" of THC. The researchers who found it named it after sphaerophorol, the chemical name of the seven-carbon building block in its structure.
How was THCP discovered?
A team led by researchers at the University of Modena and Reggio Emilia analysed an Italian medicinal cannabis variety, FM2, with high-resolution mass spectrometry. They found two compounds that had never been reported in nature: THCP and its CBD counterpart, cannabidiphorol (CBDP). They isolated both, described their structures and confirmed them by making the same molecules through stereoselective synthesis in the laboratory. The work was published in Scientific Reports in December 2019 (Citti et al., 2019).
The amounts were tiny. The FM2 extract contained about 29 µg of THCP per gram, compared with 39 mg of THC per gram, roughly a thousand times less. In 2020 Italian researchers also identified the six-carbon homologue, THCH (tetrahydrocannabihexol), in a medical cannabis variety.
What is the chemical structure of THCP?
THCP has the same ring system as THC. The difference is the alkyl side chain on the resorcinol ring: seven carbon atoms in THCP, five in THC and three in THCV. Researchers had already seen in synthetic compounds that a longer side chain can increase binding to cannabinoid receptors. THCP was the first natural cannabinoid found with a side chain longer than five carbons.
| THCP | THC | THCV | |
|---|---|---|---|
| Side chain | 7 carbons (heptyl) | 5 carbons (pentyl) | 3 carbons (propyl) |
| CB1 binding, Ki | 1.2 nM | 40 nM | 75.4 nM |
| Relative to THC | About 33 times stronger | Reference | Weaker |
| Typical amount in cannabis | Traces | Main cannabinoid in drug-type plants | Minor |
A lower Ki means stronger binding. Stronger binding in a test tube does not automatically mean a stronger effect in people.
What does THCP do?
In the same study, mice given THCP showed the four classic signs of THC-like activity: reduced movement, reduced pain response, immobility and lower body temperature (Citti et al., 2019). This is why THCP is described as intoxicating. There are no published clinical studies of THCP in people, so its effects, safety and how long it stays in the body are unknown. Read more about which cannabinoids are psychoactive.
How is THCP made?
Because the plant makes so little THCP, the discovery team also made it by stereoselective synthesis to confirm its structure (Citti et al., 2019). Matching the natural and synthetic molecules showed exactly which three-dimensional form occurs in the plant. Our article on synthetic and natural cannabinoids explains why the origin of a cannabinoid matters.
Is THCP legal in the UK?
The Misuse of Drugs Act 1971 lists "cannabinol derivatives" as Class B drugs and defines them as "tetrahydro derivatives of cannabinol and 3-alkyl homologues of cannabinol or of its tetrahydro derivatives" (MDA 1971, Schedule 2). The Home Office confirms that THC is controlled under this heading (Home Office, 2024). THCP is THC with a longer alkyl chain at the same position, so it falls within that wording. Our page Is CBD oil legal in the UK? explains how the controls work for CBD products.
From our production
We don't sell HHC or any other cannabinoid that intoxicates, and we don't sell THCA products that turn into THC when heated. We test every batch in Switzerland.
— Robin Roy Krigslund-Hansen, co-founder and CEO
Frequently asked questions
What is THCP?
THCP (tetrahydrocannabiphorol) is a cannabinoid with the same structure as THC but a seven-carbon side chain. It was first found in cannabis in 2019 and occurs only in trace amounts.
Who discovered THCP?
Italian researchers led from the University of Modena and Reggio Emilia identified THCP in the medicinal cannabis variety FM2 and published the discovery, including its chemical structure, in Scientific Reports in December 2019.
Is THCP stronger than THC?
In laboratory tests it bound to the CB1 receptor about 33 times more strongly than THC, and it caused THC-like effects in mice. There are no studies in people, so how this translates to human effects is unknown.
What is the difference between THCP and THC?
THCP has a seven-carbon side chain and THC has a five-carbon one. Otherwise their structures are the same. THC is the main cannabinoid in drug-type cannabis; THCP occurs only in traces.
Is THCP legal in the UK?
The Misuse of Drugs Act controls cannabinol derivatives, including 3-alkyl homologues of tetrahydrocannabinol, as Class B drugs. THCP falls within that definition.
Related guides
This article is for information only and does not describe any product in our shop. No Formula Swiss product contains THCP. Our CBD oils are cosmetic products for use on the skin. See our full disclaimer.
Last reviewed:
Sources
- Citti C, Linciano P, Russo F, et al. A novel phytocannabinoid isolated from Cannabis sativa L. with an in vivo cannabimimetic activity higher than Δ9-tetrahydrocannabinol: Δ9-tetrahydrocannabiphorol. Sci Rep 2019;9:20335. doi:10.1038/s41598-019-56785-1
- Misuse of Drugs Act 1971, Schedule 2 (Part II Class B; Part IV definition of cannabinol derivatives). legislation.gov.uk.
- Home Office. Drug licensing factsheet: cannabis, CBD and other cannabinoids. Updated 3 October 2024.
