Study register · detailSystematic Review · Chronic Pain · 2026
Cannabis-Based Products for Chronic Pain : An Updated Systematic Review.
Chou et al.·Annals of internal medicineImpact 4.3
MixedGRADEHigh2 citations
Samplek = 25 Studien n = 2.303 Pat.
Duration1 to 6 months
ControlPlacebo
EndpointPain intensity
Blindingdoppelblind
DesignSystematic Review
”Key finding
Highly rational THC/CBD and comparable THC/CBD products show small pain improvements, but with substantially increased adverse effects (dizziness, sedation, nausea); nabilone reduced pain moderately, but dronabinol did not; low THC/CBD products showed no benefit.
Summary
Updated systematic review of k=25 short-term RCTs (1–6 months, n=2.303; 64% neuropathic pain). Oral synthetic high-THC products (THC-only) may slightly reduce pain intensity (pooled difference −0.78 points, 0–10 scale); oromucosal extracted comparable-THC-to-CBD products probably slightly reduce pain (−0.54 points). Nabilone moderately reduced pain (−1.59 points), dronabinol did not (−0.23 points). Low-THC-to-CBD products may not improve outcomes. Moderate to large increase in dizziness, sedation, nausea with THC products.
P
PopulationAdults with chronic pain (64% neuropathic pain), pooled n=2303
I
InterventionCannabinoids (oral synthetic/purified, oromucosal extracted, THC-only, THC/CBD combinations, CBD monopreparations) – categorized by THC-to-CBD ratio
C
ControlPlacebo
O
OutcomeComparable and high THC-to-CBD ratio products slightly reduced pain intensity (pooled differences -0,54 to -0,78 points on a 0–10 scale); nabilone moderately reduced pain (-1,59 points), dronabinol did not (-0,23 points); low-THC-to-CBD products showed no demonstrable benefit; increased risk of dizziness, sedation and nausea
Confidence in the evidence
Very lowLowModerateHigh
High
The highest of four GRADE levels, the effect estimate is very reliable.
Background: Benefits and harms of cannabinoids for chronic pain are uncertain.
Purpose: To update an evidence synthesis on cannabinoids for chronic pain.
Data Sources: Ovid MEDLINE, PsycINFO, Embase, the Cochrane Library, and Scopus to 28 July 2025.
Study Selection: Randomized placebo-controlled trials.
Data Extraction: Data extraction, risk of bias, and strength of evidence were dually reviewed. Cannabinoids were categorized by tetrahydrocannabinol (THC)-to-cannabidiol (CBD) ratio (high, comparable, or low), source (synthetic, purified, extracted), and administration method.
Data Synthesis: 25 short-term (1 to 6 months) randomized controlled trials (n = 2303; 64% neuropathic pain) assessed cannabinoids. Oral synthetic/purified high THC-to-CBD (THC only) may slightly reduce and oromucosal, extracted, comparable THC-to-CBD ratio products probably slightly reduce pain severity (pooled differences, -0.78 and -0.54 points, respectively, [0 to 10 scale]), with moderate or large increased dizziness, sedation, and nausea. Among THC-only products, nabilone moderately reduced pain severity but dronabinol did not (pooled differences, -1.59 and -0.23 points, respectively). Low THC-to-CBD interventions may not improve outcomes. Although low THC-to-CBD mixed THC/CBD products may increase dizziness, sedation, and nausea, CBD alone may not increase harms.
Limitation: Variability within categories; lack of product details; unclear U.S. availability of studied products; restricted to English-language studies.
Conclusion: Comparable and high THC-to-CBD ratio cannabinoid products may result in small improvements in pain and increased common adverse events during short-term treatment of primarily neuropathic pain; among high-ratio THC-only products, nabilone (but not dronabinol) reduced pain. Low THC-to-CBD products may not improve outcomes. Studies are needed on long-term outcomes and other cannabis product types.
Primary Funding Source: Agency for Healthcare Research and Quality, U.S. Department of Health and Human Services (PROSPERO: CRD42021229579).