Scientists identified the mechanism behind cannabis-induced dry mouth: CB1 receptors on salivary gland nerves
THC reduces saliva production by activating CB1 receptors on cholinergic nerve axons in the salivary gland, and CBD reverses this effect, explaining why cannabis causes dry mouth.
Quick Facts
What This Study Found
CB1 receptors are expressed on cholinergic nerve axons innervating the submandibular gland but not on gland cells. THC (4 mg/kg) and CP55940 reduced salivation in both sexes. CBD had no effect alone but dose-dependently reversed THC effects. FAAH knockout mice had reduced salivation, confirming endocannabinoid regulation.
Key Numbers
THC dose: 4 mg/kg. CP55940: 0.5 mg/kg. CBD reversed THC-induced dry mouth dose-dependently. SR141716 (CB1 antagonist) had no effect alone. JWH133 (CB2 agonist) had no effect. FAAH KO mice had reduced salivation.
How They Did This
Immunohistochemistry to localize CB1 receptors in submandibular glands. Salivation measured in wild-type, CB1 knockout, and FAAH knockout mice after treatment with THC, CBD, CP55940, and other cannabinoid ligands. Lipidomics profiling of FAAH knockout tissue.
Why This Research Matters
Cannabis-induced dry mouth is one of the most common side effects, affecting millions of users. Understanding the mechanism opens potential therapeutic approaches for dry mouth conditions.
The Bigger Picture
The finding that CBD reverses THC-induced dry mouth adds mechanistic understanding to the "entourage effect" and could inform product formulation for medical cannabis patients.
What This Study Doesn't Tell Us
Animal study in mice. Salivation was stimulated with pilocarpine, which may not fully replicate natural salivation. Dose-response curves were limited.
Questions This Raises
- ?Could the endocannabinoid system be targeted to treat Sjogren syndrome dry mouth?
- ?Do high-CBD cannabis products cause less dry mouth than high-THC products?
Trust & Context
- Key Stat:
- CBD dose-dependently reversed THC-induced dry mouth in mice
- Evidence Grade:
- Thorough mechanistic study with multiple convergent approaches (IHC, knockout mice, pharmacology, lipidomics).
- Study Age:
- Published in 2022.
- Original Title:
- Cannabinoid CB1 receptors regulate salivation.
- Published In:
- Scientific reports, 12(1), 14182 (2022)
- Authors:
- Andreis, Kelsey, Billingsley, Jenna, Naimi Shirazi, Kian, Wager-Miller, Jim, Johnson, Clare, Bradshaw, Heather, Straiker, Alex
- Database ID:
- RTHC-03674
Evidence Hierarchy
Tests effects in animals (usually mice or rats), not humans.
What do these levels mean? →Frequently Asked Questions
Why does cannabis cause dry mouth?
THC activates CB1 receptors on nerve fibers that control saliva production, reducing salivation. The endocannabinoid system naturally regulates saliva through this same pathway.
Does CBD cause dry mouth too?
No. CBD alone had no effect on salivation and actually reversed THC-induced dry mouth in a dose-dependent manner.
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Cite This Study
https://rethinkthc.com/research/RTHC-03674APA
Andreis, Kelsey; Billingsley, Jenna; Naimi Shirazi, Kian; Wager-Miller, Jim; Johnson, Clare; Bradshaw, Heather; Straiker, Alex. (2022). Cannabinoid CB1 receptors regulate salivation.. Scientific reports, 12(1), 14182. https://doi.org/10.1038/s41598-022-17987-2
MLA
Andreis, Kelsey, et al. "Cannabinoid CB1 receptors regulate salivation.." Scientific reports, 2022. https://doi.org/10.1038/s41598-022-17987-2
RethinkTHC
RethinkTHC Research Database. "Cannabinoid CB1 receptors regulate salivation." RTHC-03674. Retrieved from https://rethinkthc.com/research/andreis-2022-cannabinoid-cb1-receptors-regulate
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.