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Study breakdown

JAMA's Comprehensive Review of What Cannabis Can and Can't Treat

Meta AnalysisModerate evidence
The takeaway

FDA-approved cannabinoids have evidence for nausea, appetite loss, and pediatric seizures, but evidence-based guidelines recommend against inhaled or high-potency cannabis for most conditions.

Clinicians advising patients about medical cannabis, patients considering cannabinoid therapies, health policy researchers tracking the evidence-practice gap.

What the researchers found

Published in JAMA — the most widely read medical journal in the world — this review synthesized the therapeutic evidence for cannabis and cannabinoids across all conditions studied in randomized trials and meta-analyses.

The strongest evidence supports three FDA-approved indications: HIV/AIDS-related anorexia (cannabinoids moderately increased body weight; SMD 0.57), chemotherapy-induced nausea and vomiting (small but significant reduction; SMD −0.29), and certain pediatric seizure disorders (CBD as Epidiolex).

For chronic pain — the most common reason people report using medical cannabis — the review found that approximately 27% of US and Canadian adults have used cannabis medicinally, with 10.5% of the US population reporting CBD use for therapeutic purposes. However, evidence-based guidelines do not recommend inhaled or high-potency cannabis (≥10% THC or ≥10 mg THC) for pain management.

The review also addressed cardiovascular risks, noting emerging evidence of harm, and highlighted the gap between public perception of cannabis as medicine and what clinical trial data actually support.

Why it matters

A JAMA review represents the medical establishment's current consensus position. The fact that it was published in 2026 — years after most US states legalized some form of cannabis — signals that the medical community is still working to align clinical practice with evidence. The review's distinction between FDA-approved cannabinoids (which have evidence) and inhaled/high-potency cannabis (which guidelines recommend against) is particularly significant.

The numbers in context

27% of US/Canadian adults report ever using cannabis medicinally. 10.5% of US population uses CBD therapeutically. Nausea/vomiting: SMD −0.29 (95% CI: −0.39 to −0.18). HIV/AIDS appetite: SMD 0.57 (95% CI: 0.22 to 0.92). Guidelines recommend against inhaled or ≥10% THC/≥10 mg THC products.

How the study worked

Narrative review with meta-analytic data published in JAMA. Synthesized evidence from randomized clinical trials and existing meta-analyses across all therapeutic indications for cannabis and cannabinoids. Covered FDA-approved products (dronabinol, nabilone, Epidiolex) and non-approved cannabis preparations.

Who was studied

N=various adults in the US and Canada using cannabis for medical purposes.

What this study cannot tell us

Narrative review format means the evidence synthesis may be selective rather than comprehensive. The rapidly evolving cannabis research landscape means some recent findings may not be captured. Focuses primarily on US-centric FDA approval framework. Does not address the full range of cannabinoid products available in legal markets.

How to read the evidence

Comprehensive narrative review published in JAMA incorporating meta-analytic data from randomized trials — represents the current medical consensus on therapeutic cannabinoids.

When this study was published

Published in 2026 in JAMA, providing the most current high-level synthesis of cannabinoid therapeutic evidence.

The bigger picture

This JAMA review serves as a reference point for the entire therapeutic cannabis landscape. It contextualizes more specific findings in this database: the chronic pain reviews (RTHC-00233, RTHC-00225), the mental health evidence (RTHC-00235), the epilepsy research (RTHC-00160, RTHC-00186, RTHC-00238), and the cardiovascular concerns (RTHC-00167, RTHC-00237). The gap between the 27% of adults who have used cannabis medicinally and the narrow set of FDA-approved indications captures one of the central tensions in cannabis medicine.

Replication

Not stated in abstract.

Funding

Not reported in abstract.

Conflicts of interest

Not reported in abstract.

Questions still open

  • Will more conditions eventually gain evidence-based support for cannabinoid treatment, or will the gap between public use and clinical evidence persist? Can harm reduction frameworks bridge the divide between guidelines that recommend against inhaled cannabis and the millions of people already using it? How should clinicians counsel the 27% of patients who have already tried medical cannabis?

Read the original research

Therapeutic Use of Cannabis and Cannabinoids: A Review.

JAMA, 335(4), 345-359

JAMA is a highly respected medical journal known for publishing peer-reviewed research.

Citation

Hsu, Michael; Shah, Arya; Jordan, Ayana; Gold, Mark S; Hill, Kevin P. (2026). Therapeutic Use of Cannabis and Cannabinoids: A Review.. JAMA, 335(4), 345-359. https://doi.org/10.1001/jama.2025.19433

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