THCP (THCP) — Glossary

Tetrahydrocannabiphorol (THCP) is a naturally occurring phytocannabinoid first identified in 2019, structurally analogous to Δ9-THC but distinguished by a seven-carbon alkyl side chain rather than a five-carbon chain, a difference associated with markedly higher binding affinity at CB1 receptors in laboratory assays.

THCP was first characterised by Italian researchers Citti et al. in a 2019 paper published in Scientific Reports, where it was isolated from a medicinal Cannabis sativa L. variety using liquid chromatography–high-resolution mass spectrometry. It occurs in the cannabis plant at very low concentrations , the 2019 paper reported levels roughly 30 times lower than Δ9-THC in the same sample , making it a minor phytocannabinoid by abundance.

The structural distinction is the length of the alkyl side chain attached to the resorcinyl moiety of the cannabinoid scaffold. Δ9-THC carries a five-carbon (pentyl) chain; THCP carries a seven-carbon (heptyl) chain. In radioligand binding assays, this extension produced a CB1 receptor binding affinity approximately 33 times greater than Δ9-THC and roughly 10 times greater at CB2 receptors, according to the Citti et al. data. Binding affinity in an isolated receptor assay does not, on its own, establish potency or effect in a living system , pharmacokinetics, receptor reserve, and downstream signalling all modulate real-world outcomes.

Research into THCP remains at an early stage. As of 2024, published in vivo and human pharmacological data are scarce, and no regulatory body; including Australia's Therapeutic Goods Administration (TGA), has approved any THCP-containing product for therapeutic use. Under Australia's Poisons Standard, cannabinoids derived from cannabis that are not specifically scheduled as approved medicines are subject to Schedule 4 (prescription only) or Schedule 9 (prohibited substance) classifications depending on their specific listing and context of supply. Individuals or entities seeking to work with novel cannabinoids in Australia must consult the current Poisons Standard and, where relevant, TGA scheduling instruments.

THCP also has a biosynthetic counterpart, THCB (tetrahydrocannabibutol, four-carbon chain), identified in the same 2019 study. The two compounds are part of a broader class of homologue cannabinoids whose pharmacological profiles are an active area of phytocannabinoid chemistry research.

Sources: