NCT05351801 · VA Office of Research and Development
Proof of Concept Trial of Cannabis Derivatives in Neuropathic Pain
What this study is about
Chronic neuropathic pain (CNP) is disabling. Research on frontline treatments for CNP, shows inconsistent outcomes and dissatisfaction among Veterans. Veterans and clinicians have shown significant interest in cannabis derivatives (THC, CBD) for neuropathic pain control, but there are no well-controlled trials guiding expectations for benefit and adverse outcomes associated with cannabis for CNP.
View original scientific description
Chronic neuropathic pain (CNP) is disabling. Research on frontline treatments for CNP, shows inconsistent outcomes and dissatisfaction among Veterans. Veterans and clinicians have shown significant interest in cannabis derivatives (THC, CBD) for neuropathic pain control, but there are no well-controlled trials guiding expectations for benefit and adverse outcomes associated with cannabis for CNP.
Interventions
DRUG
THC (Syndros)
Participants will receive a target dose of 10mg per day of THC (Syndros).
DRUG
CBD (Epidolex)
Participants will receive a target dose of 800 mg per day of CBD (Epidolex).
DRUG
THC + CBD (Nabiximols)
Participants will receive a target dose of 10.8 mg / 10 mg per day of THC + CBD (Nabiximols).
DRUG
Placebo
Placebo
Primary outcome measures
To compare the short-term efficacy of THC, CBD, or THC+CBD vs Placebo on Neuropathic Pain as measured by the Numeric Rating Scale of Pain
Time frame: Baseline, Week 6
The mean change in the weekly average of daily Numeric Rating Scale (NRS) pain score (0-10 scale; 0=no pain, 10=worst possible pain) from baseline to week 6.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- Able to provide written consent
- Veterans 21 years and older at the date of screening
- Meet diagnostic criteria for neuropathic pain as defined by the Neuropathic Pain Special Interest Group of the International Association for the Study of Pain (NeuPSIG)
- Meet criteria for persistent, high-impact pain criteria.
- Presence of allodynia confirmed by one of the screening dynamic brush tests
Exclusion criteria
- Peripheral neuropathy is not a primary source of neuropathic pain
- Hypersensitivity to THC, CBD, or THC/CBD
- Self-report of cannabis use during screening phase confirmed by positive urine toxicology for THC-COOH as measured and resulted at visit 5 before randomization
- Unwilling to refrain from using cannabis or cannabis-based products through the entire duration of the study
- Diagnosis of DSM-5 Cannabis Use Disorder in the past 6 months
- Current DSM-5 diagnosis of cannabis use disorder, substance use disorder or serious psychiatric disorders
Where
- San Diego, California
- West Los Angeles, California
- West Haven, Connecticut
- Providence, Rhode Island
- San Antonio, Texas
- Seattle, Washington
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Feb 27, 2026 · Source of record for eligibility and locations