CBC (cannabichromene): molecule, levels and legal status

Cannabichromene was described in 1966 by two teams working independently. Yehiel Gaoni and Raphael Mechoulam presented it in Chemical Communications as a new active principle of hashish. A German team, Claussen, von Spulak and Korte, published it the same year in Tetrahedron.

It is called "minor" because the plant makes little of it, not because it is marginal chemically. A review published in 2024 in the Journal of Pharmacology and Experimental Therapeutics notes that most cannabis varieties produce only small amounts. Several studies summarised in that review find no activation of the CB1 receptor, which fits the absence of a psychoactive effect.

Everything starts from CBGA, cannabigerolic acid, which our article on CBG presents as the mother molecule. Three enzymes compete for this substrate: THCA synthase, CBDA synthase and CBCA synthase. Each turns it into a different acid: THCA, CBDA or CBCA. The genetics of the variety decide which one dominates. In a CBD hemp it is CBDA synthase, and the CBCA branch stays small.

CBCA becomes CBC by losing a carboxyl group under heat and drying. It is the same reaction that turns CBDA into CBD. CBC and CBD even share the same molecular formula; only the arrangement of their atoms differs.

Published measurements confirm the order of magnitude. In 2020 the National Research Council of Canada validated a method for measuring 17 cannabinoids and applied it to five lots of milled hemp. On average, these lots contained 0.289 mg of CBC and 0.520 mg of CBCA per gram, against 5.81 mg of CBD and 15.60 mg of CBDA.

As with CBD, the total is calculated by correcting the acid form: total CBC = CBC + 0.877 × CBCA. On these lots that gives about 0.07% total CBC for 1.95% total CBD. CBC therefore weighs about 4% of the CBD.

A practical detail: the Phytogrammes product pages, checked on 23 September 2026, show a panel of six cannabinoids (CBD, CBDA, CBG, CBN, THC, THCA). CBC is not on it. A product sold for its CBC content should show that content, measured on the lot. Our guide to reading a certificate of analysis shows where to look for it.

Most data on CBC come from cells and animals. The 2024 review lists them:

• at the receptor level, CBC is the most potent activator of the TRPA1 channel among the cannabinoids tested, and it also activates TRPV1 and the CB2 receptor;
• in animals, mainly mice and rats, effects have been observed in tests of pain, inflammation and seizures, with mechanisms still debated;
• in culture, activity has been measured against some Gram-positive bacteria.

In humans, no trial has studied CBC alone. The only pharmacokinetic data, meaning what happens to the molecule in the body, come from an extract in which testing revealed more CBC than THC. The oil contained 20 mg/ml of CBD, 1.1 mg/ml of CBC and 0.9 mg/ml of THC. At the highest daily doses, participants received 26.4 mg of CBC together with 480 mg of CBD and 21.6 mg of THC. CBC remained measurable in the blood, and this dose was tolerated in that mixture.

The review's authors note that CBC products are sold freely while their safety and efficacy have almost no supporting data. CBC is not a medicine. The only authorised medicine based on cannabidiol, Epidyolex, contains purified CBD.

CBC is not on the list of narcotics. It follows the hemp framework: the order of 30 December 2021 allows Cannabis sativa L. varieties listed in the official catalogues whose Δ⁹-THC content does not exceed 0.30%, and applies that threshold to extracts and products containing them. The Conseil d'État decision of 29 December 2022 struck down the ban on selling raw flowers and leaves.

Do not confuse CBC with semi-synthetic cannabinoids. The ANSM classified HHC, HHCO and HHCP as narcotics from 13 June 2023, then H4CBD, THCP and other derivatives from 3 June 2024. CBC occurs naturally in the plant; those molecules are made by chemical conversion. Our article on the H4CBD ban traces that decision.

Swallowed, a CBC extract falls under the novel food regime, like CBD extracts: Regulation (EU) 2015/2283 only allows authorised novel foods on the market. Our overview of CBD regulation in 2026 describes the French situation.

On caution, ANSES proposed on 21 March 2025 classifying CBD as presumed toxic to reproduction. The proposal concerns CBD, not CBC, for which no equivalent data exist. By default, the same precautions apply during pregnancy and breastfeeding, as our article on the classification proposed by ANSES explains.

Isolated CBC remains rare. It turns up mainly as a minor component of full-spectrum oils, which keep the plant's whole range of cannabinoids, and of flowers. The idea that these minor components change the effect of CBD has a name, the entourage effect; it is a hypothesis, not an established result in humans. The catalogue oils are grouped in the CBD oils category.