What is CBL?

Cannabicyclol (CBL) killed a rabbit in the 1970s and has rarely been spoken about since.

Marijuana plant with cannabicyclol cannabinoid
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CBL is one of roughly 140 chemical compounds (cannabinoids) present in cannabis and is the result of cannabichromene (CBC) degradation when exposed to heat and UV light over long periods. It’s non-intoxicating and doesn’t induce a euphoric high like delta-8, delta-9, or THC-O. However, CBL could potentially be psychoactive insofar as affecting your central nervous system and altering brain functionality, thus altering mood, perception, and behavior. 

Very little is known about CBL, though it did contribute to the killing of a rabbit in the 1970s.

What is Cannabicyclol (CBL)?

Definition: CBL is short for cannabicyclol and is a non-intoxicating minor cannabinoid found in varieties of cannabis, including hemp and marijuana. It’s a photochemical product created from cannabichromene (CBC) degradation. This degradation occurs when CBC is exposed to natural elements, most notably UV light. CBL does not induce a euphoric high but could potentially affect your central nervous system and alter mood, perception, and behavior the same way as CBD and CBG, potentially making it a psychoactive substance. 

Chemical formula: CBL’s chemical formula is C21H30O2, similar to CBN, a mildly intoxicating cannabinoid and THC isomer also formed from the degradation of another cannabinoid via heat and UV light. However, what separates CBL from CBN is the lack of a double bond on its molecular structure, which is one of the reasons why CBL is likely not an intoxicating compound and probably won’t bind to cannabinoid receptors. 

Cannabicyclol molecular structure

Discovery: CBL was first discovered and isolated from the cannabis plant by Korte and Sieper in 1964. Gaoni and Mechoulam later clarified its molecular structure. Since its discovery and subsequent isolation from the cannabis plant, researchers know very little about CBL. 

An ancient cannabinoid: In an exciting twist of events, scientists discovered high percentages of CBL and CBN in 2700-year-old cannabis plant samples, which isn’t particularly surprising since both cannabinoids are formed through degradation over a long period.

Research on Cannabicyclol (CBL)

Cannabis flower in jar

Research on CBL is largely non-existent. There are currently very few studies on its pharmacological effects. This lack of research isn’t shocking. CBL isn’t only overshadowed by other cannabinoids such as CBD and THC, but it’s also a challenging cannabinoid to isolate from the cannabis plant due to existing in very small quantities. 

Of the studies that do exist, each one is preliminary and not wholly conclusive. 

An old study from 1973 shows CBL combined with other cannabinoids might inhibit prostaglandin production. Prostaglandins are a group of naturally-occurring compounds with hormone-like effects. They’re produced by the body to facilitate smooth muscle contractions and reduce injury. 

Later, in 1976, researchers discovered doses of 8mg/kg of CBL caused severe illness, convulsions, and death in one of two rabbit test subjects. The cause of this negative outcome is unclear and isn’t likely representative of CBL’s overall safety. 

Other mysterious minor cannabinoids share a similar lack in research. For example, researchers are still very much in the dark about Cannabidiphorol (CBDP), a cannabinoid found in a specially bred cannabis plant in 2019.

Benefits: What is CBL good for?

Tincture rich in cannabicyclol cannabinoid

Unfortunately, CBL’s benefits are unknown. However, we can assume it has some therapeutic qualities since its molecular structure and chemical formula are almost identical to CBD and CBC. We can also confidently assume CBL works alongside other cannabinoids and interacts with your endocannabinoid system.  

Your endocannabinoid system is a complex biological network of cannabinoid receptors, endocannabinoids, and enzymes. Together, these components work around the clock to regulate internal functions such as pain perception, inflammatory response, sleep, and mood.

When you consume CBD, for example, it prevents enzymes from breaking down valuable endocannabinoids, allowing them to target problem areas in your body with more efficiency, thus making them more effective.

Now, whether CBL affects your endocannabinoid system in the same way as CBD is unknown, but it’s not unreasonable to think CBL has some positive interactions with it. Only time will tell. 

Effects: How does CBL make you feel?

CBL’s effects are unknown. Researchers have yet to determine how CBL makes you feel after consumption. There are also no anecdotal stories from users since no CBL products exist.

Is CBL legal?

Yes. The Agriculture Improvement Act (Farm Bill), signed into law in 2018, made hemp and all hemp-derived compounds (minus delta-9) legal across all 50 states, Washington DC, and inhabited US-owned territories. CBL derived from hemp plants carrying no more than 0.3% THC by dry weight is currently legal under federal law. Therefore, the use, possession, sale, distribution, purchase, promotion, and production of hemp-derived CBL is permitted in the US without risk of penalty or prosecution.

How does CBL compare to other cannabinoids?

Cannabis plant rich in cannabicyclol cannabinoid


  • THC is an intoxicating and psychoactive cannabinoid capable of binding to CB1 receptors. This binding activity means THC induces a euphoric high and impairs thinking, judgment, perception, and behavior. 
  • The reason for THC’s binding ability is the double bonds in its molecular structure.
  • CBL isn’t an intoxicating substance, and likely doesn’t bind directly to CB1 receptors. However, it might bind to other receptor sites around the body to induce unique effects and benefits, though no research reinforces this theory. 
  • THC’s main benefits include anti-inflammation, pain relief, and sleep promotion. CBL’s benefits are largely unknown. 


  • CBL and CBN are minor cannabinoids formed from the degradation of other cannabinoids. CBL is the degradative product of CBC. CBN is the degradative product of THCA. The degradation process occurs over long periods of time. 
  • CBN is a mildly intoxicating cannabinoid with sedative effects equal to or greater than diazepam. CBL is not intoxicating, nor is it likely to be a sedative. 
  • CBN also binds to CB1 and CB2, while CBL likely doesn’t bind to either one.


Cannabicyclol (CBL) is quite possibly the biggest mystery in the cannabis industry. From killing a rabbit in the 1970s to fading into obscurity thereafter, there are a lot of unanswered questions surrounding CBL’s safety, benefits, and effects. 

To be honest, we don’t expect to see CBL gaining the spotlight in the future. Researchers are too preoccupied with CBD, CBG, THC, and delta-8, which is unfortunate because we’re pretty intrigued already — and we suppose you are too!