CBG: What It Is, Effects and Safety | PatientsCann UK

CBG

cannabigerol, "the mother cannabinoid"

pronounced: kan-uh-bih-JER-ol

The "mother cannabinoid" - the plant makes everything else from its acid form.

Neutral cannabinoidFormula: C21H32O2Intoxicating: No
Type
Neutral
Formula
C21H32O2
Intoxicating
No
Key focus
Focus & gut

Cannabigerol · 316.5 g/mol

The molecule

Chemical structure

This is the accurate skeletal structure of CBG, drawn from PubChem data. Each corner and line-end is a carbon atom, and the red O marks oxygen. Its formula is C21H32O2 and it weighs 316.5 g/mol.

FocusAnti-bacterialGut supportAnti-inflammatory

About

What is CBG?

Cannabigerol, or CBG, is often called the "mother cannabinoid". That is because its acid form, CBGA, is the raw material the plant uses to build almost every other cannabinoid. Most plants turn nearly all of their CBGA into other things, so mature flower usually contains only a little CBG.

To get more CBG, growers harvest some plants early, or breed special CBG-rich varieties. Like CBD, CBG does not make you high.

In the body

How CBG Works

CBG binds both the CB1 and CB2 receptors, but only weakly, which is why it is not intoxicating. It also acts on other targets, including alpha-2 adrenoceptors, which are involved in alertness, and serotonin receptors.

Early research, still mostly in the lab and in animals, is looking at CBG for inflammatory bowel disease, for protecting nerve cells, for mood, and as an antibacterial. Human studies are still limited, so its benefits are not yet proven.

Receptor snapshot

Where CBG Acts

The endocannabinoid system has two main receptors. Here is how strongly CBG acts on each.

CB1Brain & nervous system
Partial

Binds CB1 weakly, so it is not intoxicating.

CB2Immune system & body
Partial

Binds CB2 weakly too.

Beyond CB1 and CB2: Also acts on alpha-2 adrenoceptors and blocks 5-HT1A serotonin receptors.

In the plant

How CBG is Made

CBG comes from CBGA, the first cannabinoid acid the plant makes, by joining a molecule called olivetolic acid with a terpene building block.

Any CBGA the plant does not turn into THCA, CBDA or CBCA can be heated to become CBG. This is why CBG sits at the very start of the cannabinoid family tree.

Comes fromCBGA→ add heat →CBG

Good to know

Safety and Side Effects

CBG appears to be well tolerated in the small amount of research done so far, with few reported side effects. Because studies in people are limited, its long-term safety is not fully known.

As with any cannabinoid, tell your prescriber before adding CBG, especially if you take other medicines.

Questions

CBG: Common Questions

Why is CBG called the mother cannabinoid?
Because its acid form, CBGA, is the raw material the cannabis plant uses to build the other cannabinoids. Enzymes turn CBGA into THCA, CBDA and CBCA, which then become THC, CBD and CBC.
Is CBG intoxicating?
No. CBG binds the CB1 receptor only weakly, so it does not cause a high.
Back to full Cannabinoids Guide
Important: This page is for education only. It is not medical advice. Cannabinoid research is still developing, and many studies have been done in cells or animals rather than people. Always speak to your prescriber before changing your treatment. PatientsCann UK does not recommend any specific cannabis product.

References

  1. Nachnani, R., Raup-Konsavage, W.M. and Vrana, K.E. (2021) 'The pharmacological case for cannabigerol', Journal of Pharmacology and Experimental Therapeutics, 376(2), pp. 204-212. doi: 10.1124/jpet.120.000340.
  2. Izzo, A.A., Borrelli, F., Capasso, R., Di Marzo, V. and Mechoulam, R. (2009) 'Non-psychotropic plant cannabinoids: new therapeutic opportunities from an ancient herb', Trends in Pharmacological Sciences, 30(10), pp. 515-527. doi: 10.1016/j.tips.2009.07.006.
  3. Morales, P., Hurst, D.P. and Reggio, P.H. (2017) 'Molecular targets of the phytocannabinoids: a complex picture', Progress in the Chemistry of Organic Natural Products, 103, pp. 103-131. doi: 10.1007/978-3-319-45541-9_4.
  4. National Center for Biotechnology Information (2025) PubChem Compound Database. Bethesda: U.S. National Library of Medicine. Available at: https://pubchem.ncbi.nlm.nih.gov (Accessed: 29 July 2026).