This page is for general educational purposes and does not provide medical advice, diagnosis, or a treatment recommendation.
Medical Ozone Therapy: Uses, Evidence, and Safety Questions
Medical ozone therapy uses a controlled mixture of oxygen and ozone. Clinics may inject the gas into a joint or around soft tissue, mix it with a patient’s blood and return the blood, or use other routes. Evidence and risk differ by method. Ozone should never be inhaled; it is toxic to the lungs.
How It Is Used
For knee osteoarthritis, a clinician may inject an oxygen-ozone mixture into the joint, sometimes as a series. “Major autohemotherapy” removes blood into a closed container, mixes it with gas, and reinfuses it. Rectal insufflation and topical applications are also marketed. These approaches are not interchangeable, and results from one route cannot establish the safety or effectiveness of another.
Proposed Mechanism
Proponents propose that carefully dosed ozone creates a brief oxidative signal that may influence inflammation and antioxidant responses. Laboratory mechanisms do not establish clinical benefit, and excessive exposure can damage cells and tissue.
What the Evidence Shows
Knee osteoarthritis is one of the better-studied uses. Randomized trials and systematic reviews suggest short-term improvements in pain and function for some patients, but reviewers have repeatedly noted small samples, inconsistent protocols, and risk of bias. A 2020 review found encouraging short-term results but no clear advantage over established comparison treatments. Evidence is much weaker for broad claims involving infection, cancer, cardiovascular, neurologic, or systemic disease.
Regulatory Status and Risks
Patients should ask whether the specific ozone device, route, and claimed use have FDA authorization. Do not interpret a clinician’s license or a device registration as proof that a treatment is FDA-approved for a disease.
Injection risks include pain, bleeding, infection, tissue injury, and gas entering a blood vessel. Incorrect intravenous administration can cause gas embolism, stroke-like injury, heart or lung complications, and death. Autohemotherapy adds risks related to blood handling, contamination, clotting, and vascular access. Inhaled ozone can cause coughing, chest pain, shortness of breath, and lung damage.
What to Expect
Joint treatment is usually outpatient. Temporary soreness or pressure may occur. Ask how many sessions are proposed, what rehabilitation accompanies treatment, and what objective measure will determine whether to continue. Improvement, when reported in studies, has generally been symptom relief rather than proven regrowth of cartilage.
Questions to Ask a Provider
- Which route and concentration are you proposing, and why?
- What controlled studies support it for my exact diagnosis?
- What device is used, and what is its FDA status for this purpose?
- How do you prevent contamination, dosing errors, and gas embolism?
- What emergency equipment and training are available?
- What alternatives have stronger evidence, and what is the total cost?
Sources
- Oxygen-Ozone Therapy for the Treatment of Knee Osteoarthritis: A Systematic Review of Randomized Controlled Trials. PMID: 31679646.
- Comparison Between Intra-Articular Ozone and Placebo in Knee Osteoarthritis. PMID: 28738079.
- Intra-Articular Ozone Injection in Knee Osteoarthritis: A Systematic Review and Meta-Analysis. PMID: 30498370.
- U.S. Environmental Protection Agency. Health Effects of Ozone Pollution.