WHAT IS CBL?
Cannabicyclol (CBL) is one of the degenerative cannabinoids like cannabinol (CBN) and cannabichromene. It is a non-psychoactive member of the phytocannabinoids family formed under acidic or irradiation conditions.
As one of the minor cannabinoids, CBL is understudied even though it occurs naturally in the cannabis plant. Most information on this cannabinoids is on its structure, biosynthesis, and little to nothing about its therapeutic benefits.
It is not scheduled under the UN Convention on Psychotropic Substances and Controlled Substances Act in the United States, making it legal with other minor cannabinoids like CBC and CBN.
Korte and Sieper discovered CBL in 1964. After their discovery, they thought the product they had successfully isolated was THC since they share a similar arrangement of atoms with CBL, with CBL, having a double bond.
This led them to name the compound THC III. It was in 1967 when the cannabinoid was re-isolated and renamed to Cannabicyclol.
Contrary to what is observed in other cannabinoids, CBL is not derived from Cannabigerolic acid (CBGA); it is formed from Cannabichromene (CBC). It is formed when CBC is exposed to light or irradiation over time. These and many more reactions surrounding the identity of CBL made the early researchers doubt if it was a naturally occurring cannabinoid in the cannabis plant.
In 1971, the compound’s correct structure was discovered and found to exist in larger concentrations in harvested cannabis plants kept over time.
It was later agreed that CBL is not a naturally occurring cannabinoid but a CBC degradation product during storage. During storage, CBC is converted to Cannabicyclolic acid (CBLA-C 5 A), which is later converted to CBL via decarboxylation.
Related: CBD vs CBN
Extracting CBL from cannabis plants is almost impossible as it exists in minute quantities. One of the criteria for choosing the right strain for extraction is that it must contain a high level of CBC. The strain containing a high CBC must be kept for several years with constant exposure to light before producing a substantial amount of CBL.
The longer the time of storage, the higher the CBL content of the cannabis plant. A group of researchers in China discovered a 2,700-year-old tomb in 2008 containing lots of cannabis. After analysis, it was discovered that the cannabis plant had greater quantities of CBC, CBL, and CBN.
It is also pertinent to note that CBL may be found in large quantities in Hashish, which are often stored for several years before extraction.
HOW DOES IT WORK?
CBL is highly understudied. There is little to no information linking its activity with the endocannabinoid receptors or other body receptors. Its low concentration in the cannabis plant makes it almost impossible to extract and study.
Since it shares some similarities with the THC and CBC, there is a possibility it may adopt a similar method of activity on the cannabinoid receptors.
CBL is highly under-studied. Most of the information from research has been investigated with other cannabinoids hence making it hard to pinpoint if CBL is responsible for the activity or other cannabinoids.
In one of these research works, it was reported that a group of cannabinoids, together with CBL, could inhibit prostaglandin production. These are compounds with hormone-like effects and can regulate smooth muscle contractions. After the research, it was found that CBL exhibited the lowest biological activity among the tested cannabinoids.
Another study in 1976 reported how the administration of CBL at 8mg/kg triggered serious convulsion and death in rabbits. This research’s findings were quite unclear since the compound was administered to two rabbits but only caused that reaction in one. 
- CBL is produced from an aging cannabis plant high in CBC concentration. Its low concentration in the cannabis plant makes it one of the understudied members of the cannabinoid family.
- Its mode of activity and possible therapeutic potential is still unknown.
- Since CBL is not scheduled under the UN Convention on Psychotropic Substances and The Controlled Substances Act in the United States, its use may be legal in most parts of the world, including the United States.
 Korte, F., Sieper, H., 1964. Chemical classification of plants. XXIV. Hashish constituents by thin-layer chromatography. Journal of Chromatography 13 (1), 90 – 98.
 Russo, E. B., Jiang, H. E., Li, X., Sutton, A., Carboni, A., del Bianco, F., Mandolino, G., Potter, D. J., Zhao, Y. X., Bera, S., Zhang, Y. B., Lü, E. G., Ferguson, D. K., Hueber, F., Zhao, L. C., Liu, C. J., Wang, Y. F., & Li, C. S. (2008). Phytochemical and genetic analyses of ancient cannabis from Central Asia. Journal of experimental botany, 59(15), 4171–4182. https://doi.org/10.1093/jxb/ern260
 Burstein, S., Levin, E., & Varanelli, C. (1973). Prostaglandins and cannabis—II inhibition of biosynthesis by the naturally occurring cannabinoids. Biochemical Pharmacology, 22(22), 2905–2910. DOI:10.1016/0006-2952(73)90158-5
 Martin P, Consroe P. Cannabinoid induced behavioral convulsions in rabbits. Science. 1976;194(4268):965-967. DOI:10.1126/science.98205