CBG—The 'Minor' Cannabinoid That Fights Nerve Pain Through a Different Pathway | Research

The takeaway

Cannabigerol (CBG) reduced both acute and chronic nerve pain in rodent models, working primarily through CB2 receptors rather than the CB1 receptors targeted by THC.

Pain researchers exploring non-THC cannabinoids, people with neuropathic pain looking for alternatives, and pharmaceutical scientists interested in CB2-targeted therapies.

What the researchers found

Most cannabis research focuses on THC and CBD. This study investigates cannabigerol (CBG)—a "minor" cannabinoid found in smaller quantities in the plant but with a distinct pharmacological profile.

Using both acute pain tests (formalin and hot plate) and a chronic neuropathic pain model (spinal nerve ligation in rats), the researchers found that CBG-enriched extract had significant pain-reducing effects. The optimal dose was 30 mg/kg orally.

What makes this mechanistically interesting is the pathway. CBG's pain-relieving effects worked primarily through CB2 receptors—not CB1 receptors (the ones THC activates to produce a "high") and not through BDNF or TNF pathways. CB2 receptors are found mainly on immune cells, including the microglia in the spinal cord. This immune-mediated mechanism was confirmed by the finding that CBG reduced microglial density and spinal morphological changes at the injury site.

This CB2-mediated mechanism is significant because it suggests CBG could provide pain relief without the psychoactive effects of THC (which works through CB1). The spinal nerve ligation model is particularly relevant—it mimics the type of nerve damage that causes chronic neuropathic pain in humans, which is notoriously difficult to treat.

CBG also upregulated CB2 receptor expression in the spinal dorsal horn, suggesting it doesn't just activate existing receptors but actually increases the density of the receptors it works through.

Why it matters

Neuropathic pain affects millions and responds poorly to conventional treatments. RTHC-00170 showed that nerve pain patients use cannabis more intensively—suggesting they're seeking relief that other treatments don't provide. CBG's CB2-mediated mechanism offers the possibility of cannabinoid pain relief without the cognitive and psychoactive effects of THC, which limit THC's clinical utility for chronic daily pain management.

The numbers in context

Optimal dose: 30 mg/kg oral CBG. 14-day daily treatment in the chronic pain model. Pain-relieving effects mediated through CB2R. Reduced microglial density at spinal injury site. CB1R, BDNF, and TNF did not play major roles.

How the study worked

Animal study. Acute pain: formalin and hot plate tests in male Swiss mice. Chronic pain: spinal nerve ligation (SNL) in 8-week-old male Wistar rats, with CBG-enriched extract administered orally daily for 14 days. Assessed thermal and mechanical sensitivity, microglial density, spinal morphology, and receptor involvement (CB1R, CB2R, BDNF, TNF).

Who was studied

Male Swiss mice and male Wistar rats used in pain models.

What this study cannot tell us

Animal study only—no human data. CBG-enriched extract (not pure CBG), so other cannabinoids may contribute to effects. Only male animals used—sex differences in pain processing are well-documented. The 14-day treatment window is short for modeling chronic pain management. Oral bioavailability of CBG in humans may differ from rodents. CBG is currently expensive to produce in quantity.

How to read the evidence

Preclinical animal study with systematic receptor analysis—mechanistically informative but requires human clinical testing.

When this study was published

Published in 2025, reflecting growing research interest in minor cannabinoids beyond THC and CBD.

The bigger picture

This expands the cannabinoid pain toolkit beyond THC and CBD. RTHC-00182 showed CBD alone didn't help knee osteoarthritis, and RTHC-00158 found THC:CBD specifically helped cancer pain. CBG represents a third cannabinoid approach—targeting CB2 immune-mediated pathways specifically for neuropathic pain. The reduced microglial density finding connects to RTHC-00190's review of CBD's neuroinflammatory mechanisms, suggesting multiple cannabinoids can modulate neuroinflammation through different receptor pathways.

Replication

Not stated in abstract.

Funding

Not reported in abstract.

Conflicts of interest

Not reported in abstract.

Questions still open

Will CBG show the same pain-relieving effects in human neuropathic pain trials? Could CBG be combined with other cannabinoids for enhanced effect? Does the CB2-mediated mechanism mean CBG is truly non-psychoactive at therapeutic doses?

Read the original research

Cannabigerol Modulates Cannabinoid Receptor Type 2 Expression in the Spinal Dorsal Horn and Attenuates Neuropathic Pain Models.

Pharmaceuticals (Basel, Switzerland), 18(10)

Pharmaceuticals is a peer-reviewed journal focusing on drug development and therapeutic applications.

View on PubMed ↗Publisher’s paper ↗

Citation

Rezende, Bismarck; Fernandes, Gabriel Gripp; de Simas Gonçalves, Vitória Macario; Nascimento, Gabriela Guedes; Marques, Kethely Lima; de Oliveira, Barbara Conceição Costa Azeredo; Dos Santos, Yure Bazilio; de Andrade, Maria Eduarda Barros; Calumbi, Karine Simões; Maia, Eduardo Perdigão; Trefilio, Luisa Menezes; Antunes, Fernanda; Fontes-Dantas, Fabrícia Lima; Montes, Guilherme Carneiro. (2025). Cannabigerol Modulates Cannabinoid Receptor Type 2 Expression in the Spinal Dorsal Horn and Attenuates Neuropathic Pain Models.. Pharmaceuticals (Basel, Switzerland), 18(10). https://doi.org/10.3390/ph18101508