Ozone therapy is being investigated as a treatment for long COVID, with a small but growing body of evidence showing improvements in fatigue, brain fog, and exercise tolerance. A 2024 randomized controlled trial found a 71% response rate in the treatment group versus 45% in controls. That is promising, but the studies are still small. Here is what the evidence actually shows and how ozone compares to other approaches.
This article covers the proposed mechanisms, the clinical evidence to date, how ozone therapy is delivered for long COVID, and how it stacks up against HBOT, which has a stronger evidence base for post-COVID recovery.
Key Takeaways
- A 2024 RCT showed ozone therapy improved long COVID symptoms in 71% of treated patients versus 45% of controls (p=0.0325)
- Proposed mechanisms include immune modulation, mitochondrial support, and improved microcirculation
- Evidence is growing but still limited: an evidence map identified 13 clinical studies involving 271 total patients
- HBOT currently has stronger evidence for long COVID, with larger trials and FDA breakthrough therapy designation
- Typical ozone protocols for long COVID involve 10 to 20 sessions of MAH or 10-pass at a cost of $2,000 to $9,000
Why Long COVID Is Hard to Treat
Long COVID (post-acute sequelae of SARS-CoV-2, or PASC) affects an estimated 10 to 30% of people who contract COVID-19. Symptoms persist for months or years after the acute infection resolves. The most common complaints are fatigue, brain fog, exercise intolerance, shortness of breath, joint pain, and autonomic dysfunction.
The underlying pathology is still being worked out, but several mechanisms are implicated:
- Persistent immune activation and chronic inflammation
- Endothelial dysfunction and microclotting in small blood vessels
- Mitochondrial dysfunction leading to impaired cellular energy production
- Viral persistence in certain tissues (spike protein or viral reservoirs)
- Autonomic nervous system dysregulation
No single treatment addresses all of these mechanisms. This is why interest in therapies like ozone and HBOT has grown: they target multiple pathways simultaneously.
How Ozone Is Proposed to Help Long COVID
Immune Modulation
Long COVID involves a stuck immune response. Pro-inflammatory cytokines remain elevated long after the virus is cleared. Ozone therapy at controlled doses has been shown to modulate cytokine production, potentially helping to resolve this chronic inflammatory state.
Ozone stimulates anti-inflammatory pathways and activates Nrf2, the master regulator of antioxidant defense. For long COVID patients whose oxidative stress markers are elevated, this dual action (reducing inflammation while boosting antioxidant capacity) addresses two core problems at once.
Mitochondrial Support
Many long COVID patients have measurable mitochondrial dysfunction. Their cells cannot produce ATP (energy) efficiently, which explains the profound fatigue and exercise intolerance.
The Konig-Lahodny research on high-dose ozone therapy demonstrated improved mitochondrial reserve capacity in peripheral blood cells. While this study was not specific to long COVID, the finding is directly relevant to a condition defined by cellular energy deficits.
Microcirculation Improvement
Microclotting is increasingly recognized as a driver of long COVID symptoms. Fibrin deposits in capillaries reduce blood flow to tissues, creating pockets of hypoxia that impair organ function. Ozone therapy improves red blood cell flexibility, increases 2,3-DPG (enhancing oxygen release), and has mild anticoagulant properties that may help address this microvascular pathology.
Clinical Evidence
The 2024 Randomized Controlled Trial
A pilot RCT published in International Immunopharmacology (2024) randomized long COVID patients to receive either major ozone autohemotherapy or sham treatment. The results showed a 71% response rate in the ozone group compared to 45% in the control group (p=0.0325). Fatigue scores improved significantly, as measured by the FACIT Fatigue Scale (p=0.001).
This is the strongest piece of evidence to date. However, it was a pilot study with a relatively small sample size, and larger trials are needed to confirm the findings (Tirelli et al., 2024, doi:10.1016/j.intimp.2024.113194).
Evidence and Gaps Map
A systematic evidence map published in BMC Infectious Diseases (2023) identified 13 clinical studies involving 271 total patients who received ozone therapy for COVID-19 (both acute and post-acute). All 13 studies reported positive results, with improvements in both mild-to-severe acute cases and post-acute symptoms (Fern and ez-Cuadros et al., 2023, doi:10.1186/s12879-023-08329-0).
The authors noted that while results were consistently positive, the level of scientific evidence is still limited due to small sample sizes, heterogeneous study designs, and lack of standardized protocols.
Rectal Insufflation Study
One study compared nutritional supplementation plus rectal ozone insufflation versus nutritional supplementation alone. Improvements in COVID-19 symptoms were observed in 85% of patients receiving ozone plus supplementation compared to 37% with supplementation alone (p < 0.05).
“Although the number of studies on ozone therapy for COVID-19 increases day by day, the level of scientific evidence is still limited. The research base requires larger studies and more robust evidence before ozone therapy becomes a standard treatment recommendation.”
Frontiers in Medicine (2026)
A study published in Frontiers in Medicine examining the efficacy of major ozone autohemotherapy in patients with post-COVID syndrome added to the growing body of evidence supporting ozone for long COVID symptom management. The study reported improvements across multiple symptom domains, particularly fatigue and cognitive function.
Ozone vs. HBOT for Long COVID
Both ozone therapy and hyperbaric oxygen therapy (HBOT) are being used for long COVID. Here is how they compare:
| Factor | Ozone Therapy | HBOT |
|---|---|---|
| Evidence level | 13 clinical studies, 1 RCT, 271 patients total | Multiple RCTs, larger sample sizes, FDA breakthrough therapy designation |
| Proposed mechanism | Immune modulation, oxidative preconditioning, mitochondrial support | Hyperoxygenation, angiogenesis, neuroplasticity, anti-inflammatory |
| Session time | 30 to 90 minutes | 60 to 120 minutes |
| Sessions needed | 10 to 20 | 30 to 40 |
| Cost per session | $150 to $900 | $200 to $400 |
| Total protocol cost | $2,000 to $9,000 | $6,000 to $16,000 |
| Accessibility | Available in many integrative clinics | Requires specialized chamber facility |
HBOT currently has stronger evidence for long COVID. It has received FDA breakthrough therapy designation for post-COVID cognitive impairment, and multiple RCTs with larger sample sizes have shown benefits for brain fog, fatigue, and exercise capacity. For a detailed look at the HBOT evidence, see our guide on HBOT for lingering COVID-19 symptoms.
That said, ozone therapy is more accessible (more clinics offer it), less expensive per session, and requires fewer total sessions. Some practitioners use both therapies together for long COVID patients.
Delivery Methods for Long COVID
Major Autohemotherapy (MAH)
The most common approach. Blood is drawn, ozonated, and reinfused. Provides systemic immune modulation. Most studies on ozone for long COVID used this method.
10-Pass Ozone Therapy
Higher-dose version of MAH. Used for severe or treatment-resistant long COVID cases. Delivers approximately 140,000 mcg of ozone versus 8,000 mcg in standard MAH. The mitochondrial benefits documented in the Konig-Lahodny research used this high-dose protocol.
Rectal Insufflation
A lower-cost option that can be used between MAH or 10-pass sessions. One study showed 85% improvement rate when combined with nutritional supplementation.
Typical Protocol for Long COVID
- Weeks 1 to 2: MAH twice per week. Start at moderate ozone concentrations. Assess tolerance and initial response.
- Weeks 3 to 6: Continue MAH twice weekly. Add rectal insufflation on non-MAH days if tolerated. Increase ozone concentrations gradually.
- Weeks 7 to 10 (if needed): Consider transitioning to 10-pass for patients with persistent symptoms. Weekly sessions.
- Maintenance: Monthly MAH or 10-pass sessions for 3 to 6 months. Some patients taper off completely. Others maintain periodic sessions long-term.
Realistic Expectations
Based on the available evidence and clinical reports:
- Fatigue is the symptom most consistently improved by ozone therapy
- Brain fog improves in many patients, though response varies
- Exercise tolerance tends to improve over a course of treatment
- Autonomic symptoms (POTS, heart rate variability issues) are less predictably responsive
- Not everyone improves. The 2024 RCT showed 71% responded, meaning 29% did not. Long COVID is heterogeneous, and no single treatment works for everyone.
Most patients who respond notice improvement within the first 4 to 6 sessions. If no improvement is observed after 10 sessions, the therapy is unlikely to be helpful for that individual.
Cost
- Standard MAH protocol (10-20 sessions): $1,500 to $6,000
- 10-Pass protocol (6-10 sessions): $3,000 to $9,000
- Rectal insufflation (adjunct, 10 sessions): $750 to $1,500
- Monthly maintenance: $150 to $900
Insurance does not cover ozone therapy for long COVID in the United States.
The Bottom Line
Ozone therapy for long COVID has moved beyond pure speculation. A randomized controlled trial now exists showing statistically significant benefit. The proposed mechanisms align well with the known pathophysiology of post-COVID syndrome. And 13 clinical studies, while small, are consistently positive.
But the evidence is still early. HBOT has a stronger evidence base for this indication. Ozone therapy’s advantages are accessibility, lower cost per session, and fewer total sessions needed. For long COVID patients weighing their options, the most honest assessment is that ozone therapy is a reasonable adjunctive treatment to explore, with realistic expectations about both the potential benefits and the limitations of current evidence.
References
- Tirelli, U., et al. (2024). A pilot randomized controlled trial of major ozone autohemotherapy for patients with post-acute sequelae of COVID-19. International Immunopharmacology, 141, 113194. doi:10.1016/j.intimp.2024.113194
- Fernandez-Cuadros, M.E., et al. (2023). Clinical effectiveness of medical ozone therapy in COVID-19: the evidence and gaps map. BMC Infectious Diseases, 23, 395. doi:10.1186/s12879-023-08329-0
- Izadi, M., et al. (2022). The Mito-Hormetic Mechanisms of Ozone in the Clearance of SARS-CoV2 and in the COVID-19 Therapy. Biomedicines, 10(9), 2258. doi:10.3390/biomedicines10092258
- Konig, J., et al. (2022). Ozone high dose therapy (OHT) improves mitochondrial bioenergetics in peripheral blood mononuclear cells. Journal of Dermatological Treatment.
- Zilberman-Itskovich, S., et al. (2022). Hyperbaric oxygen therapy improves neurocognitive functions of post-COVID-19 patients. Scientific Reports, 12, 11252.
Medical Disclaimer
The content on BaricBoost.com is for informational purposes only and is not intended as a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.
Author
Seph Fontane Pennock is the founder of BaricBoost.com and Regenerated.com, a clinic directory for regenerative medicine serving 10,000+ providers across the United States. He previously built and sold PositivePsychology.com, which grew to 19 million users and became the largest evidence-based positive psychology resource on the web. Seph brings direct experience as an HBOT patient, having completed protocols at clinics across three continents while navigating mold illness, systemic inflammation, and autoimmune conditions. His treatment journey includes hyperbaric oxygen therapy, peptide protocols, NAD+ therapy, and consultations with specialists from Dubai to Cape Town to Mexico. This combination of entrepreneurial track record and lived patient experience shapes everything published on BaricBoost.com. Every article is grounded in peer-reviewed research, informed by real clinical encounters, and written for patients making high-stakes treatment decisions. Seph's focus is on bringing transparency, scientific rigor, and practical guidance to the hyperbaric oxygen therapy space.
