Written by Tabish Mehraj, PhD. Following the intervention (i.e., 60 days or the trial endpoint), both the placebo and cannabis groups showed comparable improvements in pain scores, with no statistically significant differences in pain intensity. The CBD-rich cannabis oil was well-tolerated, as no patient experienced any serious adverse events or clinically significant changes in serum biomarkers.

Knee osteoarthritis (OA) is one of the most progressive inflammatory conditions worldwide and is a common cause of chronic pain and disability worldwide. Patients often experience joint stiffness and reduced mobility, which affects their quality of life. Standard treatments such as nonsteroidal anti-inflammatory drugs (NSAIDs) and opioids only provide some symptomatic relief and are frequently associated with adverse effects for long-term use. Thus, there is a need for alternative safe therapies. Cannabidiol (CBD), a derivative of Cannabis sativa, is a non-intoxicating phytocannabinoid that has anti-inflammatory and analgesic properties. The endocannabinoid system, which regulates inflammation and pain signaling, is present in osteoarthritic joints and provides a biological rationale for cannabinoid-based therapies. However, clinical evidence that supports CBD for osteoarthritis remains limited and inconsistent.

For the assessment of CBD-rich cannabis oil in pain management and function in individuals with knee osteoarthritis, investigators conducted the CANOA trial, a randomized, double-blind, placebo-controlled clinical study in Brazil. 45 adults between the ages of 30–70 years with radiographically confirmed knee osteoarthritis and moderate-to-severe pain were grouped to receive either a full-spectrum CBD-rich cannabis oil or a placebo consisting of medium-chain triglyceride (MCT) oil for 60 days. Participants in the treatment group received an oral CBD dose of 45 mg/day taken twice daily.

Results/ Findings

• The CBD and placebo groups were comparable in clinical characteristics, demographics, medication use, and laboratory values at study entry.

• Both groups showed significant improvements in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) reported as 66.82 (95% CI: 59.30-74.33) and Visual Analog Scale (VAS) pain scores (8.50, 95% CI: 7.22-8.86) after 60 days, with no significant differences between CBD-rich cannabis oil and placebo.

• Sleep quality (PSQI), depression (BDI), and health-related quality of life (SF-12) improved in both groups, but improvements were similar across treatment groups, with negligible effect sizes.

• Comparable improvements in both groups suggest a substantial placebo response, a common finding in chronic pain trials.

• CBD-rich cannabis oil was well tolerated, with no serious adverse events or clinically significant changes in liver function, kidney function, or lipid profiles. Reported adverse effects were mild and occurred at similar rates in both groups.

The investigators assessed many possible explanations for the lack of clinical benefit. Although the product was described as a full-spectrum cannabis oil, lab analyses detected no significant tetrahydrocannabinol (THC) or other minor cannabinoids. There were some limitations to this study. The study consisted of mostly Caucasian women. The treatment used a CBD-dominant formulation with little exposure to compounds that may contribute to the proposed “entourage effect.” In addition, the daily CBD dose of 45 mg was lower than doses reported in earlier clinical studies. The relatively small sample size and single-center design also limit the generalizability of the findings. Larger multicenter studies with longer treatment durations and broader evaluation of cannabinoid combinations will be needed to determine whether specific cannabis formulations offer benefits for osteoarthritis pain.

Overall, this randomized clinical trial found that oral CBD-rich cannabis oil was safe and well-tolerated but did not provide greater pain relief or improvements in quality of life than placebo among patients with knee osteoarthritis. While these findings do not support the use of this specific low-dose CBD-rich formulation as an effective analgesic for knee OA, they contribute valuable evidence to a rapidly evolving field and underscore the importance of conducting rigorous clinical trials before cannabinoid therapies are widely adopted for chronic pain management.

Click here to read the full text study.

Posted July 23, 2026.

Dr. Tabish Mehraj is a pharmaceutical scientist with expertise in pharmaceutics, drug delivery, and formulation development. She earned her PhD in Pharmaceutical Sciences from the University of Mississippi, where her research focused on the formulation, optimization, and characterization of lipid-based nanocarriers for targeted liver delivery of antimalarial therapeutics. Dr. Mehraj has also served as an ORISE Fellow at the U.S. Food and Drug Administration (FDA), where she evaluated the effects of formulation and process design on the quality and performance of intravaginal drug delivery systems and developed bio-relevant in vitro drug release testing methods. She has teaching experience in pharmaceutical and life sciences courses and has authored peer-reviewed publications, book chapters, and conference presentations. Dr. Mehraj is an active member of the American Association of Pharmaceutical Scientists and has been recognized by honor societies including Rho Chi and Gamma Beta Phi.

Reference:

1. Mojoli, A., Haider, O., Fakih, Y., Luz Gonçalves, M. V., Zepeda Rojas, B., Xaia, G., … & Nascimento, F. P. (2025). Effects and safety of a CBD-rich Cannabis sativa oil in knee osteoarthritis: a double-blind, randomized, placebo-controlled trial–CANOA–cannabis for osteoarthritis. Frontiers in Pharmacology, 16, 1657065.