CBC (Cannabichromene): Is It Really the Third-Most Common Cannabinoid?

Every few months another cannabinoid becomes the new thing on hemp shop shelves, and CBC keeps getting the same description: the third-most common cannabinoid in the plant, right behind THC and CBD. It doesn't get you high, chemists first isolated it from hashish in 1966, and it is now sold in purified, concentrated form.

So what is CBC, and does it really rank third? The chemistry is clear. The ranking is much weaker, and nearly everything said about its benefits comes from mice and cell cultures.

Cannabichromene in plain chemistry

Cannabichromene, CBC for short, is one of the hundreds of cannabinoids the cannabis plant makes. Its formula is C21H30O2, the same atoms as THC and CBD in a different arrangement. The plant builds it from CBGA, the acid our guide to CBG describes as the starting point for THC, CBD and CBC. An enzyme called CBCA synthase turns CBGA into CBCA, the acid form, and heat or time then turns CBCA into CBC, the same decarboxylation step that turns THCA into THC. Light pushes it one step further, into a breakdown product called cannabicyclol, or CBL.

Two research groups described CBC in 1966. A German team reported in the journal Tetrahedron that it was the first compound isolated from hashish which contains the skeleton of chromene, a ring structure that gave the molecule its name. In Israel, Yehiel Gaoni and Raphael Mechoulam, the chemists who had first isolated THC two years earlier, worked out its structure the same year.

CBC does not get you high. It binds only weakly to CB1, the receptor behind THC's high, and reviews describe it as non-intoxicating.

Third place depends on the plant

That third-place label is hard to find in the research. A July 2026 review in the Journal of Cannabis Research describes CBC as the fourth most abundant constituent in many chemovars, meaning chemical varieties of the plant. In everyday high-THC weed, it falls further back.

In a 2024 paper in Frontiers in Public Health, University of Mississippi researchers averaged the cannabinoid content of cannabis seized across the US from 2013 to 2022. THC came to about 13 percent. CBN came next at 0.72 percent, then CBG at 0.49 percent, with CBC and CBD tied at 0.29 percent. A 2018 study of 33 strains from Canadian licensed producers found that nine strains from its high-THCA groups had no detectable CBC at all.

The ranking shifts because CBC tends to follow CBD. A 2021 study of 21 strains found that CBD-dominant plants carried more CBC, along with more CBD and its relatives. In older measurements, CBC usually made up between 0.05 and 0.3 percent of the plant, a 2024 paper in the journal Metabolites notes.

Young plants make the most

CBC follows an odd timeline. A 2009 study in the journal Euphytica by plant breeder Etienne de Meijer and colleagues noted that CBC is reported to dominate the cannabinoid fraction of juveniles and to decline with maturation, and their own inbred lines confirmed it. In plain words, young plants make mostly CBC, and THC or CBD takes over as they grow. A 2023 study in Phytochemistry describes CBCA as the first cannabinoid to build up in seedlings, shortly after they sprout.

A few rare plants keep that young chemistry all the way to harvest. De Meijer's team called the trait a prolonged juvenile chemotype and found it came with fewer of the stalked resin glands that coat a mature bud. In those plants, less light meant a higher share of CBC. A later GW Pharma patent application by de Meijer describes a clone with 58 percent CBC among its cannabinoids, selected from an Afghan hashish landrace, and notes that such plants are uncommon.

Our Afghan Hash Plant Auto comes from the same part of the world: its page traces it to landrace genetics from the Mazar-i-Sharif region of northern Afghanistan, crossed with BF Super Auto #1. It is listed at 22 percent THC, finishes 75 to 80 days from seed, and smells of sandalwood with a sweet, hash-like taste. Its page does not list CBC, so treat it as a taste of the hash genetics the CBC story started with, not as a CBC source.

Lab studies behind the CBC benefits

Most of what we know about the CBC cannabinoid comes from mice and from cells in dishes, and it works differently from THC. CBC leans toward CB2, a cannabinoid receptor found mostly on immune cells, and it strongly activates TRPA1, the nerve sensor that detects the burn of mustard and wasabi. A 2024 review in the Journal of Pharmacology and Experimental Therapeutics calls it the most potent TRPA1 activator among the cannabinoids tested. The results behind most CBC benefits claims look like this:

• Inflammation. In a 2010 mouse study, CBC reduced paw swelling triggered by a bacterial toxin.
• Pain. In a 2024 mouse study, injections of CBC eased pain from light touch in mice with nerve damage.
• Mood. In standard mouse tests used to screen antidepressants, CBC showed antidepressant-like effects at 20 milligrams per kilogram, while CBD needed 200.
• Skin. In a 2016 lab study, CBC cut acne-like fat production in skin oil gland cells.
• Bacteria. In lab dishes, CBC stopped the growth of MRSA, a drug-resistant staph germ, at 1 to 2 micrograms per milliliter.

The inflammation study shows the pattern. In it, both CBC and THC elicited dose-dependent anti-inflammatory effects, meaning bigger doses calmed the swelling more. CBC did it without the CB1 or CB2 receptors, and a dose of THC too small to do anything on its own made CBC's effects in other tests stronger. Every one of these results comes from injected doses in rodents or from cells in a dish, so none of them tells you what a joint or a gummy will do.

The unexamined day is a wasted opportunity. Reflect on what you did, what you learned, and how you can improve.

John Dewey

CBC vs. CBD, and the missing trials

The CBC vs. CBD comparison is uneven. CBD has an FDA-approved drug, Epidiolex, cleared in 2018 for two seizure disorders. CBC has no approved use, though in a mouse model of Dravet syndrome, one of the conditions Epidiolex treats, CBC was as effective as CBD at reducing seizures, according to the 2024 review.

The only human data we found come from a 2022 pilot study of 43 healthy adults, in which CBC came mixed with CBD and THC in one product. The authors concluded that CBC may be absorbed more readily than the other two when taken together, and the study was built to track blood levels, not benefits. Meanwhile, the 2024 review warns that over-the-counter CBC products are being widely utilized with little or no evidence of their safety or efficacy. Side by side, the two compare like this:

• Intoxication. Neither one gets you high.
• Targets. CBC leans toward CB2 and TRPA1, while CBD has minimal direct effects on CB1 or CB2, according to the 2024 Metabolites paper.
• Evidence. CBD has controlled human trials behind its seizure drug, and CBC has none.
• Plant partners. CBC tends to rise in CBD-dominant plants, not in high-THC ones.
• Drug tests. In a 2020 study, two common urine screens for THC did not react to CBC or CBD, though both reacted to CBN.

Buying CBC raises one more question. The federal hemp law signed in November 2025 stops counting cannabinoids "synthesized or manufactured outside the plant" as hemp, Forbes reported, and that covers lab-made CBC even though the plant makes the same molecule. Most of the new rules, that one included, take effect on December 11, 2026.

Growing and storing for a fuller cannabinoid mix

No grower can make an ordinary plant produce lots of CBC, because CBC-rich plants are rare variants that breeders had to find and select. What you can control is how much CBC survives after harvest. Light turns CBC into CBL, so dry buds in the dark, store them whole in opaque, airtight containers, and keep them somewhere cool.

Keep the amounts in perspective, too. At 0.3 percent CBC, the top of the usual 0.05 to 0.3 percent range, a gram of flower holds about 3 milligrams. The highest daily dose in the 2022 human study, 26.4 milligrams, would take close to 9 grams of that flower.

For a strain with old hash roots, Hindu Kush is a pure indica landrace from the mountains between Afghanistan and Pakistan, where its page notes farmers grew it for hashish for centuries. It flowers in 55 to 65 days at 26 percent THC and tastes of sweet sandalwood and earth with a clean citrus finish. Its page lists THC, not CBC.

Small amounts, big claims

CBC is a real, non-intoxicating cannabinoid, built from CBGA and first isolated from hashish in 1966. Calling it the third-most common cannabinoid oversells it: a 2026 review puts it fourth in many chemical varieties, and in typical high-THC weed it trails CBN and CBG. Young plants make the most of it, and the rare high-CBC plants had to be found and selected.

The CBC benefits in the headlines come from mice and cells, not people. CBD has an approved drug and human trials, while CBC so far has one small study that tracked blood levels.

Read the lab report before you pay extra for CBC. Barney's Farm has been developing premium cannabis genetics since the 1980s, with over 40 Cannabis Cup wins. Explore our full seed catalog and find strains bred for every climate and skill level.