Cannabis Has Not Been Shown to Treat Kidney Stones
Medical cannabis is sometimes promoted as a possible treatment for kidney-stone pain, but the available evidence does not show that cannabis dissolves stones, speeds their passage, or reliably controls renal colic.
Kidney stones are solid mineral deposits that form when certain substances become concentrated in urine. A stone can cause severe, wave-like pain as it moves through the urinary tract, along with nausea, blood in the urine, or difficulty urinating. Larger stones, urinary obstruction, infection, dehydration, or uncontrolled pain may require urgent medical treatment. The National Institute of Diabetes and Digestive and Kidney Diseases describes the symptoms that warrant medical attention.
What the research actually shows
Interest in cannabinoids and kidney health partly comes from research on the endocannabinoid system, a network of receptors and signaling molecules involved in pain, inflammation, and organ function. A 2019 review, “Endocannabinoid System and the Kidneys: From Renal Physiology to Injury and Disease,” discussed evidence that cannabinoid receptors are present in kidney tissue and may influence processes such as inflammation, fibrosis, and acute kidney injury.
That review did not study cannabis as a treatment for kidney stones. Much of the evidence it examined came from laboratory and animal models, so the findings cannot be interpreted as proof that marijuana or a cannabis-derived product benefits people with nephrolithiasis.
Similarly, a widely cited study of cannabidiol (CBD) and kidney injury found that CBD reduced oxidative stress, inflammation, cell death, and impaired kidney function in mice given the chemotherapy drug cisplatin. The 2009 study was a preclinical experiment involving drug-induced kidney damage—not kidney stones and not human patients. It therefore provides a biological hypothesis for further research, rather than evidence for using CBD during an episode of renal colic.
Human evidence is limited—and not clearly positive
A 2023 randomized, double-blind, placebo-controlled trial tested an FDA-approved CBD oil in 90 patients after ureteroscopy and ureteral-stent placement for urinary stones. Participants received either 20 milligrams of CBD oil or placebo daily for three days. The researchers found no significant difference in pain, stent-related discomfort, or opioid use between the groups. The trial concluded that CBD was safe in that setting but did not improve the measured outcomes.
Another study analyzed self-reported marijuana use and kidney-stone history in U.S. National Health and Nutrition Examination Survey data. It found an association between marijuana use and a lower reported likelihood of kidney stones among men, but not across the overall study population. Because the research was cross-sectional and observational, it cannot establish that cannabis prevented stones. Differences in hydration, diet, health status, or other behaviors could have influenced the result. The study authors called for further research on dose, product type, and possible mechanisms.
Safety and standard care
Cannabis products can cause drowsiness, dizziness, impaired judgment, drug interactions, and gastrointestinal effects. CBD products sold outside the prescription-drug system may also contain amounts of CBD or THC that differ from their labels. Frequent cannabis use has been associated with recurrent severe vomiting, a condition that can contribute to dehydration—a concern for people vulnerable to kidney stones. The National Center for Complementary and Integrative Health summarizes the known benefits, uncertainties, and risks of cannabis and cannabinoids.
For a suspected stone, cannabis should not be used to delay evaluation or replace evidence-based treatment. Management depends on the stone’s size, location, and whether it is blocking urine flow. Small stones may pass with observation, fluids when medically appropriate, and prescribed pain relief, while larger or obstructing stones may require a urologic procedure. NIDDK outlines current approaches to kidney-stone treatment and prevention.
Overall, laboratory studies suggest that cannabinoid signaling may affect kidney biology, but that is different from demonstrating a treatment for kidney stones. Human evidence remains sparse, and the strongest stone-specific clinical trial to date did not find CBD helpful for postoperative stent discomfort or opioid reduction. Anyone with severe or persistent flank pain, fever, vomiting, blood in the urine, or difficulty urinating should seek medical care promptly.
