NCT06414473 · University of Florida
CBD for Knee Osteoarthritis
(SLACK-OA)
What this study is about
Osteoarthritis is a disease that affects millions of Americans and is the leading cause of persistent pain and physical disability in the older adult population. Many physically active Americans have reported pain-relieving effects of cannabidiol (CBD) that can reduce or eliminate use of nonsteroidal anti-inflammatory drugs (NSAIDs) for activity-related pain with minimal to no side effects.
View original scientific description
Osteoarthritis is a disease that affects millions of Americans and is the leading cause of persistent pain and physical disability in the older adult population. Many physically active Americans have reported pain-relieving effects of cannabidiol (CBD) that can reduce or eliminate use of nonsteroidal anti-inflammatory drugs (NSAIDs) for activity-related pain with minimal to no side effects. Long-term use of over-the-counter medications, including NSAIDs, can pose a significant health risk, and therefore clinical research on the safety and efficacy of CBD is needed.
Interventions
DRUG
Cannabidiol (CBD) Extract
Administered thrice daily (with food) using a sublingual route of administration
DRUG
Placebo
Administered thrice daily (with food) using a sublingual route of administration
Primary outcome measures
Patient-Reported Outcomes version of the Common Terminology Criteria for Adverse Events (PRO-CTCAE)
Time frame: Weekly until 1 month
Categorical scale, None or not at all (0) and very severe or very much (4), higher scores mean worse outcome
Theoretical Framework of Acceptability Questionnaire (TFAQ)
Time frame: Baseline and 1 month
Likert scale, 1 and 5, higher scores mean worse outcome
Self-report Ratings of Knee Pain
Time frame: Baseline and 1 month, daily until 1 month
Numeric Rating Scale, 0 and 10, higher scores mean worse outcome
Physical Activity
Time frame: Daily until 1 month
Accelerometer measures step counts per day
Western Ontario and McMaster Universities Arthritis Index (WOMAC)
Time frame: Baseline and 1 month
Categorical scale, none (0) and extreme (4), higher scores mean worse outcome
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
- established clinical diagnosis of knee osteoarthritis (KOA)
- moderate to severe knee pain (≥4/10) with physical activity in one or both knees
Exclusion criteria
- pregnant (urine pregnancy test) or lactating
- current cannabis (THC and/or CBD) use (urine drug screen)
- any prior or ongoing medical condition that, in the investigators' opinion, could adversely affect the safety of the subject
- any major surgery within 3 months prior to recruitment or planned orthopedic surgery for any time during this study which would interfere with the ability to report pain or quality of life outcome measures
- any exposure to another investigational drug within 3 months prior to screening
- current use of any enzyme-modifying drugs, including strong inhibitors or strong inducers of cytochrome P (CYP) enzymes
- history of:
- suicidal ideation or self-harm behavior
- seizure disorder or traumatic brain injury,
- liver or kidney disease, and
- cardiovascular diseases
Where
- Gainesville, Florida
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 Sep 17, 2025 · Source of record for eligibility and locations