CBG
Cannabigerol
Cannabigerol (CBG) is the biosynthetic precursor from which CBD, THC, and CBC are all derived. Present in low concentrations in most strains (<1%), it is non-psychoactive and shows early promise for inflammatory bowel disease, glaucoma, and neuroprotection.
Quick Facts
- Molecular Formula
- C₂₁H₃₂O₂
- Molecular Weight
- 316.48 g/mol
- Boiling Point
- 52°C (126°F)
- Legal Status (U.S.)
- Hemp-derived CBG (<0
- Research Status
- Early-stage research
About CBG
Cannabigerol occupies a unique position in cannabis biochemistry: CBGA (cannabigerolic acid) is the "mother cannabinoid" from which all other major cannabinoids are synthesized. Enzymatic conversion of CBGA produces THCA, CBDA, and CBCA — which then decarboxylate to THC, CBD, and CBC respectively. This means most CBG is "used up" in the biosynthesis of other cannabinoids, leaving only trace amounts (<1%) in mature cannabis plants.
Breeders have developed high-CBG strains by harvesting early (before full enzymatic conversion) or through selective breeding. These strains can contain 15–20% CBG.
CBG's pharmacology is distinct from both CBD and THC. It acts as a partial agonist at CB1 and CB2 receptors (with lower affinity than THC), an α2-adrenoceptor agonist, a 5-HT1A antagonist, and a TRPV1 agonist. It also inhibits the reuptake of GABA, anandamide, and norepinephrine.
The most compelling clinical evidence for CBG is in inflammatory bowel disease. A 2013 study in Biochemical Pharmacology found CBG significantly reduced inflammation and nitric oxide production in a murine colitis model. For glaucoma, CBG has been shown to reduce intraocular pressure in animal models. A 2021 survey study (n=127) found self-reported benefits for anxiety, chronic pain, and depression, but this is low-quality evidence.
CBG is at an early stage of clinical research — most evidence is preclinical. The neuroprotection findings in Parkinson's and Huntington's disease models are intriguing but require human translation.
Receptor Affinity
- CB1 partial agonist (low affinity)
- CB2 partial agonist
- α2-adrenoceptor agonist
- 5-HT1A antagonist
- TRPV1 agonist
Key Mechanisms
- Partial CB1/CB2 agonism — anti-inflammatory and analgesic effects
- GABA reuptake inhibition — potential anxiolytic and muscle-relaxant effects
- α2-adrenoceptor agonism — may contribute to intraocular pressure reduction
- 5-HT1A antagonism — distinct from CBD's partial agonism at same receptor
- Inhibits keratinocyte proliferation — potential psoriasis application
- Neuroprotective effects in preclinical models via antioxidant and anti-inflammatory mechanisms
Clinical Uses & Evidence
Graded using a modified GRADE framework. Grade A = strong evidence; B = moderate; C = preliminary.
Inflammatory Bowel Disease
Grade CStrong preclinical evidence in murine colitis models. No human RCTs completed. Phase I/II trials ongoing.
Key study: Borrelli et al., Biochem Pharmacol 2013
Glaucoma
Grade CAnimal studies show intraocular pressure reduction. No human trials. Mechanism may involve α2-adrenoceptor agonism.
Key study: Colasanti et al., Exp Eye Res 1984
Anxiety
Grade CSurvey data and preclinical evidence only. No RCTs. 5-HT1A antagonism is a plausible mechanism but requires clinical validation.
Key study: Russo et al., Cannabis Cannabinoid Res 2021
Neuroprotection (Parkinson's, Huntington's)
Grade CPreclinical models show dopaminergic neuroprotection and reduced neuroinflammation. Human translation unproven.
Key study: Valdeolivas et al., Neurotherapeutics 2015
Side Effects
Drug Interactions
α2-adrenoceptor agonism may have additive blood pressure-lowering effects
CBG inhibits several CYP enzymes in vitro; clinical significance unknown
Always consult a pharmacist or physician before combining cannabis with prescription medications. This list is not exhaustive.
Dosing Notes
No established clinical dosing. Consumer products typically contain 10–25 mg CBG per serving. Bioavailability data limited. Clinical trials are ongoing to establish therapeutic doses.
Dosing information is for educational purposes only. Consult a licensed healthcare provider for personalized guidance.
Legal Status
Hemp-derived CBG (<0.3% THC) is federally legal in the U.S. under the 2018 Farm Bill. Cannabis-derived CBG follows state cannabis laws.
Key Sources
- Beneficial effect of the non-psychotropic plant cannabinoid cannabigerol on experimental inflammatory bowel disease. Biochemical Pharmacology, 2013.
- Neuroprotective properties of cannabigerol in Huntington's disease. Neurotherapeutics, 2015.
- User perspectives on cannabigerol (CBG). Cannabis and Cannabinoid Research, 2021.