Systematic review found cannabis-based medicines reduced neuropathic pain in most but not all RCTs | Research

The takeaway

Of 22 randomized controlled trials, 15 found significant pain reduction with cannabis-based medicines for neuropathic pain conditions, particularly when using personalized dosing strategies.

Pain specialists, neurologists, clinical pharmacologists, patients with neuropathic pain

68% of RCTs found significant neuropathic pain reduction

What the researchers found

Among 22 RCTs of cannabis-based medicines for neuropathic pain, 15 reported significant pain reductions for conditions including multiple sclerosis, spinal cord injuries, diabetic neuropathy, postherpetic neuralgia, HIV-associated neuropathy, and peripheral neuropathic pain. Positive outcomes were more common with personalized, adjusted dosing. Seven trials found no significant pain relief versus placebo, though some showed improvements in secondary outcomes like mood and sleep.

Why it matters

Neuropathic pain is notoriously difficult to treat, and many patients do not respond to first-line medications. This comprehensive review shows that cannabis-based medicines can help, but the evidence is complicated by study limitations and variable outcomes.

The numbers in context

22 RCTs reviewed; 15 (68%) found significant pain reduction; 7 (32%) found no significant relief; conditions covered: MS, SCI, diabetic neuropathy, postherpetic neuralgia, HIV neuropathy, peripheral neuropathy, CRPS, chronic radicular pain

How the study worked

Systematic review of literature from January 2003 to December 2024 using Web of Science, PubMed, and MEDLINE. Identified 22 RCTs evaluating CT-3, THC, CBD, THC/CBD combinations, and cannabidivarin for neuropathic pain across multiple conditions.

What this study cannot tell us

Reviewed studies had small sample sizes and short durations. High placebo response rates in pain trials reduce statistical power. Psychoactive effects of THC may unblind participants. Heterogeneity in cannabinoid types, doses, and conditions limits direct comparisons across studies.

How to read the evidence

Systematic review of RCTs is a strong study design, but the underlying trials had small samples, short durations, and potential unblinding, resulting in moderate overall confidence.

When this study was published

2025 publication reviewing studies from 2003-2024

The bigger picture

The pattern of positive results with personalized dosing and negative results with fixed dosing suggests that cannabis-based pain treatment may require individualized approaches rather than standardized protocols, which has implications for both clinical practice and future trial design.

Questions still open

What patient characteristics predict response to cannabis-based medicines for neuropathic pain? Would longer trials with adaptive dosing protocols produce more consistently positive results?

Common questions

Which neuropathic pain conditions responded best?

Multiple sclerosis, spinal cord injury, diabetic neuropathy, postherpetic neuralgia, and HIV-associated neuropathy all showed significant pain improvements in at least some trials, particularly those using personalized dosing.

Why did some trials fail to show benefit?

Seven of 22 trials found no significant pain relief. Contributing factors included high placebo response rates common in pain trials, fixed rather than personalized dosing, potential unblinding from psychoactive effects, and small sample sizes reducing statistical power.

Read the original research

Are Cannabis-Based Medicines a Useful Treatment for Neuropathic Pain? A Systematic Review.

Biomolecules, 15(6)

View on PubMed ↗Publisher’s paper ↗

Citation

Almuntashiri, Nawaf; El Sharazly, Basma M; Carter, Wayne G. (2025). Are Cannabis-Based Medicines a Useful Treatment for Neuropathic Pain? A Systematic Review.. Biomolecules, 15(6). https://doi.org/10.3390/biom15060816