Effects of cannabinoids on knee osteoarthritis pain

Cannabinoid Interactions With Central and Peripheral Pain Mechanisms in Osteoarthritis of the Knee

Phase 2 Interventional University of Michigan · NCT04992624

This study is testing if daily treatment with THC, CBD, or both can help people with knee osteoarthritis feel less pain and improve their symptoms.

Quick facts

PhasePhase 2
Study typeInterventional
Enrollment200 (estimated)
Ages21 Years to 75 Years
SexAll
SponsorUniversity of Michigan Academic / other
Locations1 site (Ann Arbor, Michigan)
Trial IDNCT04992624 on ClinicalTrials.gov

What this trial studies

This clinical trial aims to investigate how daily treatment with Tetrahydrocannabinol (THC), Cannabidiol (CBD), or a combination of both affects pain and symptoms in patients with knee osteoarthritis. Participants will undergo a screening process and, if eligible, will be randomly assigned to receive either THC, CBD, a combination of both, or a placebo without knowing which treatment they are receiving. Clinical pain assessments will be conducted at multiple time points throughout the 16-week treatment period, followed by a 2-week follow-up. The study hypothesizes that CBD will reduce inflammation, THC will alter pain perception in the central nervous system, and the combination will provide both benefits.

Who should consider this trial

Good fit: Ideal candidates are individuals diagnosed with knee osteoarthritis experiencing moderate to severe chronic knee pain for at least six months.

Not a fit: Patients who have used cannabis or CBD in the month prior to enrollment may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide new treatment options for managing knee osteoarthritis pain using cannabinoids.

How similar studies have performed: Other studies have shown promise in using cannabinoids for pain management, but this specific approach is novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Ability to read and speak English to allow for written informed consent, phenotyping, and patient-reported outcomes measures
* Willingness to participate in a drug intervention trial
* Diagnosis of osteoarthritis (OA) of the knee by a medical provider (confirmed by checking medical records)
* Chronic knee pain, defined as moderate to severe knee pain for ≥ 6-month duration
* No use of cannabis or CBD in the past in the month prior to study enrollment as per self-report
* Fibromyalgia (FM) Survey Criteria score available. The questionnaire will be assessed by the research team for scoring. We will recruit enough patients to satisfy the spectrum of FM scores in four quartiles based on our previously existing data. Once a quartile is filled (approximately 40 patients enrolled), then we will not include more people from that quartile.
* Self-reported normal visual acuity or correctable (with corrective lenses- glasses or contacts) to at least 20/40 for reading instructions in the MRI and visual sensitivity testing
* No contraindications to magnetic resonance imaging (MRI) (for example (e.g.), metal implants)
* Able to lie still on their back for 1-1.5 hours during MRI
* Willingness to refrain from pain medications such as non-steroidal anti-inflammatory drugs (NSAIDs) and acetaminophen for 12 hours prior to neuroimaging and Quantitative Sensory Testing (QST)
* Willingness to refrain from alcohol and nicotine before QST and neuroimaging (alcohol and nicotine consumption is allowed after testing is completed)
* Willingness to refrain from physical activity or exercise that would cause significant muscle and/or joint soreness for 48 hours prior to testing (routine exercise or activity that does not lead to soreness is acceptable)
* Willingness to maintain a stable treatment regimen for chronic knee OA pain during the clinical trial (e.g., not initiating a new course of physical therapy)
* No use of adjunctive pain medications or stable chronic daily use of adjunctive pain medications (excluding opioids)
* Willingness to avoid grapefruit juice or food products for the duration of the study;
* Females of reproductive potential must agree to use acceptable birth control from the screening visit and until the completion study drug administration. Sexually active male participants and/or their female partners must agree to use effective contraception during study drug treatment of the male participant. Male participants may also agree not to donate sperm during study drug treatment

Exclusion Criteria:

* Individuals who are actively applying for or in litigation for compensation or disability and other aspects associated with potential secondary gain per self-report
* Inability to provide written informed consent
* Previous total knee arthroplasty
* Planned total knee arthroplasty within the time frame of the study
* Severe physical impairment (e.g., blindness, deafness, paraplegia)
* Co-morbid medical conditions that may significantly impair physical functional status (e.g., history of non-skin malignancy, or autoimmune disorder)
* Use of cannabis or CBD in the past month per self-report and/or drug screen
* Current opioid use (excepting tramadol) per self-report and/or drug screen
* Current valproate, clobazam, or warfarin use per self-report or medical records
* Current use of moderate or strong inhibitors of cytochrome p450 (CYP) enzymes CYP3A4 and CYP2C19, strong inducers of CYP3A4 or CYP2C19, moderate or strong inhibitors/inducers of CYP2C9, and narrow therapeutic index drugs (e.g., cyclosporine, amphotericin B). Participants will also not be allowed to start using these drugs during the study period if they wish to stay in the study
* Self-reported allergies to sesame oil or cannabis/cannabinoids
* Self-reported medical or psychiatric conditions that in the judgment of study personnel would preclude participation in this study (e.g., schizophrenia, malignancy, psychosis, suicidal ideation, history of substance abuse; note that stable anxiety and depression are not exclusions)
* Pregnant or nursing
* Liver failure
* Self-reported liver cirrhosis
* Active diagnosis or current symptoms of hepatitis by self-report
* Self-reported uncontrolled diabetes
* Blood pressure at screening above 180 systolic and/or 120 diastolic
* Resting heart rate at screening less than 50 beats per minute (bpm) or greater than 100 bpm;
* Elevated liver enzymes and bilirubin (measured via blood test at screening):

  * Serum total bilirubin ≥ 2.5 milligrams per deciliter (mg/dL); or,
  * Alanine Aminotransferase (ALT) or Aspartate Aminotransferase (AST) ≥ 3x upper limit normal (ULN); or,
  * Alkaline phosphatase ≥ 2 times ULN
* Severe cardiovascular disease (examples: history of myocardial infarction, unstable angina, severe coronary artery disease, congestive heart failure, or severe valvular abnormalities) that is self-reported by patient or by medical record
* Severe claustrophobia precluding MRI
* Unable to fit in or lie comfortably in MRI
* Diagnosed peripheral neuropathy
* Diagnosed or self-reported epilepsy or history of seizures
* Current head injury or history of head injury (e.g., traumatic brain injury)
* Any impairment, activity, behavior, or situation that in the judgment of the study team would prevent satisfactory completion of the study protocol

Where this trial is running

Ann Arbor, Michigan

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Osteoarthritis, KneeOsteoarthritis of the KneeCannabidiolTetrahydrocannabinol
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.