Research study · Biomedicines · 2025
Long-Term Efficacy and Safety of Inhaled Cannabis Therapy for Painful Diabetic Neuropathy: A 5-Year Longitudinal Observational Study
Verified on PubMed Oxford CEBM Level 1B: Randomized Controlled Trial
A 2025 observational study in Biomedicines tested cannabis in pain. The results are encouraging but cannot prove the cannabis was the cause. This study suggests that for some patients with difficult nerve pain from diabetes, long-term use of inhaled cannabis may offer sustained relief and reduce reliance on stronger pain medications, though the lack of.
In plain language
Study overview
This study followed 52 people with long-lasting nerve pain caused by diabetes who had not improved with standard medicines. Each person was given medical cannabis breathed in through a vaporizer or smoked, with the amount adjusted to their pain, and they were checked once a year for five years.
Findings
The results are encouraging but cannot prove the cannabis was the cause. Over the five years, people reported much less pain, needed far fewer strong painkillers, and their blood sugar readings improved somewhat, with few side effects.
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The deeper readScientific analysis
Background/Objectives: Diabetic neuropathy (DN) is a prevalent complication of diabetes mellitus, affecting up to 50% of long-term patients and causing significant pain, reduced quality of life, and healthcare burden. Conventional treatments, including anticonvulsants, antidepressants, and opioids, offer limited efficacy and are associated with adverse effects. Emerging evidence suggests that cannabis, acting via the endocannabinoid system, may provide analgesic and neuroprotective benefits. This study evaluates the long-term effects of inhaled cannabis as adjunctive therapy for refractory painful DN. Methods: In this prospective, observational study, 52 patients with confirmed painful DN, unresponsive to at least three prior analgesics plus non-pharmacological interventions, were recruited from a single clinic. Following a 1-month washout, patients initiated inhaled medical-grade cannabis (20% THC, <1% CBD), titrated individually. Assessments occurred at baseline and annually for 5 years. Results: Of 52 patients, 50 completed follow-up. Significant reductions occurred in BPI pain severity, interference, LANSS score, and HbA1c; analgesic use decreased markedly. Cannabis dose correlated with pain relief (r = 0.74, p < 0.001). No serious adverse events were reported; mild side effects occurred in 15.4% of patients. Conclusions: Inhaled cannabis showed sustained pain relief, improved glycemic control, and opioid-sparing effects in refractory DN over 5 years, with a favorable safety profile. These findings are associative due to the observational design, and randomized controlled trials are needed.
The paper
Citation
Robinson D, Khatib M, Lavon E, Kafri N, Abu Rashed W, Yassin M Long-Term Efficacy and Safety of Inhaled Cannabis Therapy for Painful Diabetic Neuropathy: A 5-Year Longitudinal Observational Study. Biomedicines (2025). PubMed 41153689 · DOI
Limitations the authors noted
Observational design with no placebo or control group; causality cannot be established. Single-center, small sample (n = 52), with 2 deaths and selection bias. Lead investigator managed both clinical care and subject assessment. Inhaled dosing variability not accurately quantifiable; strain data not recorded. Use of last observation carried forward for missing data; exploratory analyses without multiplicity adjustment. Conflict of interest and funding statements are limited; no external funding declared.
In practice
Why this matters
This study suggests that for some patients with difficult nerve pain from diabetes, long-term use of inhaled cannabis may offer sustained relief and reduce reliance on stronger pain medications, though the lack of a control group means we cannot be certain these benefits are caused by the therapy itself.
Frequently asked questions
Clinical Questions & Answers
What were the primary clinical findings regarding Cannabis and Adverse events?
The results are encouraging but cannot prove the cannabis was the cause. Over the five years, people reported much less pain, needed far fewer strong painkillers, and their blood sugar readings improved somewhat, with few side effects.
What study limitations or clinical safeguards should patients keep in mind?
Observational design with no placebo or control group; causality cannot be established. Single-center, small sample (n = 52), with 2 deaths and selection bias. Lead investigator managed both clinical care and subject assessment.
Browse related research
Condition: Adverse events Condition: Diabetes Condition: Pain Topic: Cannabis Topic: Medical cannabis Topic: Smoked cannabis
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Reviewed by Dr. Caplan on October 29, 2026.
This page is general education about a published study. It is not medical advice and does not create a doctor-patient relationship. For care specific to you, book a consultation.