Ozone Therapy and Hyperbaric Oxygen Claims: Established vs Unproven Uses and Where They Are Covered
Ozone therapy and hyperbaric oxygen are different things. See which hyperbaric uses are established, which claims are unproven, what a federal rule says about ozone, and where to read more.
Content last updated . This page has not been medically reviewed.
Urgent first
Carbon monoxide poisoning, a diver with symptoms, or a severe burn is an emergency: call 911. Do not wait for a chamber appointment. This page is information only and does not replace medical care.Two different treatments
Ozone therapy and hyperbaric oxygen therapy (HBOT) are often sold side by side in wellness and longevity clinics, but they are not the same. HBOT means breathing 100% oxygen in a special chamber at raised air pressure. [1] Ozone is a different gas, and ozone therapy is a different practice. This page gives a short, plain summary of each and points to our fuller guides.Hyperbaric oxygen: established uses and unproven claims
| Question | What the sources found | Label |
|---|---|---|
| Which uses are established? | Harvard Health lists conditions the FDA has approved HBOT to treat, including hard-to-heal wounds such as diabetic foot ulcers [2]. Medicare's national coverage list includes acute carbon monoxide intoxication, decompression illness, gas embolism and gas gangrene [3] | Established for specific, listed conditions |
| Alzheimer's, autism, cancer, Lyme disease? | Harvard Health says some centers claim HBOT treats these, but the FDA has not cleared or approved HBOT for them [2] | No good evidence of benefit in the sources we read |
| Everything else Medicare does not list | Medicare says all indications not specified in its list are not covered [3] | Coverage rule, not a trial result |
Medicare's list is a coverage rule from a 2017 version of the policy, and it is not the same as the FDA's list. [3]
Risks. Complications are uncommon but include ear and sinus pain, eardrum rupture, temporary vision changes and, rarely, lung collapse. [2] High oxygen concentrations also raise the risk of fire. [1] In an August 2025 letter, the FDA said it was aware of reports of serious injuries and deaths with HBOT devices, and also said it believes serious events are rare. [1] Harvard Health says the FDA recommends treatment only at an accredited facility. [2]
Ozone therapy: what a federal rule says
The FDA's regulation on ozone, 21 CFR 801.415, states that ozone is a toxic gas with no known useful medical application in specific, adjunctive or preventive therapy. [4] It adds that inhaled ozone can irritate the lungs enough to cause pulmonary edema. [4]One overview of the research is an evidence and gap map that characterized 26 systematic reviews of ozone treatment. [5] Its authors are affiliated with ozone therapy societies in Brazil and Italy. [5] A gap map shows where studies exist, not whether a treatment works, and the authors themselves wrote that its effectiveness needs to be researched. [5]
Proper evidence not found for ozone as a treatment for cancer or other serious diseases. We searched PubMed (2026-10-22) for ozone therapy trials with cancer survival outcomes and found no such trial. The few results were unrelated or were reviews about mouth and jaw conditions, which we did not assess here. We did not find an FDA page that clears ozone therapy for these uses.
Where each topic is covered in full
- Hyperbaric: established indications, wellness and longevity claims, and hyperbaric vs supplemental oxygen.
- Ozone: ozone therapy claims and IV vitamin and ozone therapy claims.
- Method: how to evaluate a therapy claim.
Frequently asked questions
Is hyperbaric oxygen the same as ozone therapy?
No. HBOT is breathing 100% oxygen in a pressurized chamber. [1] Ozone is a different gas, and a federal regulation describes it as toxic with no known useful medical application in specific, adjunctive or preventive therapy. [4]
What is hyperbaric oxygen actually used for?
Established uses include carbon monoxide poisoning, decompression illness, gas gangrene and hard-to-heal wounds such as diabetic foot ulcers. [3][2]
Does hyperbaric oxygen treat autism, cancer or Alzheimer's disease?
Harvard Health says the FDA has not cleared or approved HBOT for these conditions. [2]
Is hyperbaric oxygen safe?
Harvard Health says it is considered safe for FDA-approved conditions, but complications such as ear pain and eardrum rupture can occur, and fire is a risk with high oxygen concentrations. [2][1]
Does ozone therapy have good trial evidence?
We found no trial evidence for serious diseases, and an ozone-society gap map says effectiveness needs to be researched. [5]
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Who should check with a clinician first
References
- FDA, Follow Instructions for Safe Use of Hyperbaric Oxygen Therapy Devices, letter to health care providers (August 25, 2025). Read 2026-10-22.
- Harvard Health Publishing, Hyperbaric oxygen therapy: Evidence-based uses and unproven claims (page dated December 9, 2024). Read 2026-10-22.
- Centers for Medicare & Medicaid Services, National Coverage Determination: Hyperbaric Oxygen Therapy (20.29), version effective 04/03/2017. Read 2026-10-22.
- U.S. Code of Federal Regulations, Title 21, section 801.415 Maximum acceptable level of ozone. Read 2026-10-22.
- Serra MEG et al., The role of ozone treatment as integrative medicine: an evidence and gap map, Frontiers in Public Health 2023 (PubMed abstract). Read 2026-10-22.