Cannabinoid Science 101: What Is Cannabicyclol (CBL)?

The chemical structure of cannabicyclol, cannabis buds in the palm of a hand, and cannabis leaves

Cannabicyclol (CBL) is a little-studied phytocannabinoid that occurs naturally in the cannabis plant. Very little is known about CBL or its potential in medicine. Most existing research into CBL has focused on the structure and biosynthesis of the molecule itself, and the few studies that have looked into its use in specific medical applications have not yielded promising results.

Cannabicyclol (also known as CBL) is one of the least studied phytocannabinoids of the cannabis plant. Until now, no biomedical research has taken place with respect to CBL or its medical applications. Rather, scientists have simply identified CBL as a constituent of the cannabis plant and its biosynthesis, but have not studied the ways in which it affects humans.

Structure and properties of the CBL molecule

CBL has the molecular formula C₂₁H₃₀O₂, identical to many other cannabinoids including THC, CBD, CBC and CBG. However, all these molecules differ slightly in the arrangement of their atoms, giving them significantly different effects.

The chemical structure of cannabicyclol
The CBL molecule

CBL itself differs from THC in that it contains no double bond within its molecule. Lacking a double bond entirely, CBL is not considered to have psychoactive potential, and it is not yet known if it has affinity with the cannabinoid receptors.

A woman wearing a stethoscope round her neck. She is holding out a cannabis leaf

CBL in the cannabis plant

CBL is known to occur as a decarboxylation product of Cannabicyclolic acid (CBLA-C 5 A).  

CBL has been found in an ancient sample of cannabis discovered in a Chinese tomb and dated to approximately 2700 BCE. In this sample, CBN and CBL were respectively the two largest fractions. CBD levels were much lower and THC was undetectable (although the presence of CBN and other metabolites indicates it was once high in THC).

White-gloved hands touching a cannabis plant

Medical potential of CBL

Very little is known about the medical potential of CBL. It has been investigated along with several other cannabinoids for its potential to inhibit production of prostaglandins (compounds that have hormone-like effects, such as regulating smooth muscle contractions). However, CBL was found to have the lowest biological activity of all tested compounds.

In one study on rabbits published in 1976, it was found that administration of CBL caused no effects at 1mg/kg, but caused convulsions and death when administered at 8mg/kg. However, CBL was only administered to two rabbits, and this effect was only seen in one! Thus, it is clear that more research into CBL is necessary.

  • Disclaimer:
    This article is not a substitute for professional medical advice, diagnosis, or treatment. Always consult with your doctor or other licensed medical professional. Do not delay seeking medical advice or disregard medical advice due to something you have read on this website.


3 thoughts on “Cannabinoid Science 101: What Is Cannabicyclol (CBL)?”

  1. Scott Messenger

    Cbl is the only chemical, that if i heard right.Can kill you,and what amount was dose amount,that 6 dose killed the test subject.cannabis compounds at what rate does cbl occur

    1. Scarlet Palmer - Sensi Seeds

      Hi CannaWorld,

      I just tried it on this post and it does for me? Can you let me know exactly what happened and I’ll pass it on to our IT folks.

      Thank you!

      With best wishes,


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