Hyperbaric Oxygen Therapy for Long COVID: Does the Research Support It?

Mark was 38, a high school teacher in Austin, and six months past his COVID infection when he realized something was seriously wrong. The fatigue he could push through. But standing in front of his chemistry class, unable to recall a concept he'd taught for 12 years, terrified him. His doctor ran tests. Everything came back normal. "It's Long COVID," she told him. "We don't have great treatments yet."

Mark's story is common. An estimated 20 million Americans have been diagnosed with Long COVID, and between 10% and 26% of adults who contract COVID-19 develop persistent symptoms lasting months or years. Brain fog, crushing fatigue, and pain top the list.

Hyperbaric oxygen therapy for Long COVID has emerged as one of the most researched treatment options for this condition. Multiple randomized controlled trials now show significant improvements in cognitive function, fatigue, sleep, and quality of life. But the treatment is not FDA-approved for Long COVID, insurance rarely covers it, and a full course can cost thousands.

This guide breaks down what the clinical research actually shows, who it may help, what treatment looks like, and how to find a clinic near you.

What is Long COVID and why is it so hard to treat?

Long COVID, also called post-COVID condition, describes persistent symptoms that last three or more months after a COVID-19 infection. More than 200 symptoms have been documented. The most common include fatigue (affecting roughly 59% of patients), shortness of breath (41%), and joint or muscle pain (39%).

Brain fog is the hallmark symptom. Nearly half of Long COVID patients report memory problems or difficulty concentrating. Researchers have found that patients with persistent brain fog show higher levels of stress hormones and inflammatory markers in their brains compared to those who fully recovered.

The condition does not discriminate. While women are affected at higher rates (45% prevalence vs. 37% in men) and those over 65 face elevated risk, Long COVID can hit anyone at any age.

Why treatments have been so difficult to find

Long COVID likely involves multiple overlapping mechanisms: persistent inflammation, microclotting, mitochondrial dysfunction, and autonomic nervous system disruption. This complexity means no single drug addresses every symptom.

As of early 2026, no treatment has received FDA approval specifically for Long COVID. Patients are left piecing together symptom management strategies while researchers race to find evidence-based solutions.

That is where hyperbaric oxygen therapy enters the picture.

How hyperbaric oxygen therapy works for Long COVID

Hyperbaric oxygen therapy delivers 100% oxygen at pressures higher than normal atmospheric levels, typically 2.0 to 2.4 ATA (atmospheres absolute). Inside a pressurized chamber, your blood plasma absorbs significantly more oxygen than it can under normal conditions.

For Long COVID, the proposed mechanisms target several core problems simultaneously:

Reducing neuroinflammation. The elevated pressure drives oxygen into brain tissue that has been chronically inflamed since infection. This helps reduce inflammatory markers and supports tissue repair.

Restoring blood flow. Long COVID is associated with microclotting and impaired blood vessel function. Hyperbaric oxygen therapy promotes new blood vessel growth (angiogenesis) and improves microcirculation.

Supporting mitochondrial function. Fatigue in Long COVID is linked to mitochondrial dysfunction. Increased oxygen availability helps restore cellular energy production.

Triggering neuroplasticity. Research shows that specific HBOT protocols can stimulate the growth of new neural connections. A 2022 brain imaging study found measurable changes in brain connectivity and microstructure after treatment.

These aren't theoretical benefits. They have been observed in controlled clinical trials; the next section digs into the evidence.

If you are exploring treatment options for persistent post-COVID symptoms, browse Long COVID clinics in the FindHBOT directory to see the 143 clinics currently offering HBOT for this condition.

What the clinical research shows

The evidence for hyperbaric oxygen therapy in Long COVID has grown substantially since 2022. Here are the most significant studies.

The landmark randomized controlled trial (2022)

The strongest evidence comes from a randomized, sham-controlled, double-blind trial conducted at the Sagol Center for Hyperbaric Medicine in Israel. Published in Scientific Reports, 73 patients with Long COVID symptoms lasting at least three months were randomized to receive either 40 sessions of HBOT at 2.0 ATA or sham treatment.

The HBOT group showed statistically significant improvements in:

• Cognitive function (attention, information processing speed, executive function)
• Psychiatric symptoms (depression, anxiety)
• Fatigue severity
• Sleep quality
• Pain levels

Brain MRI scans confirmed the subjective improvements. Researchers observed measurable increases in brain blood flow and changes in white matter microstructure in the treatment group.

One-year follow-up: do the benefits last? (2024)

A critical question for any Long COVID treatment is durability. In February 2024, the same research team published a longitudinal follow-up study in Scientific Reports tracking 31 patients from the original trial.

The findings were encouraging. Quality of life improvements, measured using the SF-36 questionnaire, showed a similar magnitude of improvement at one year as immediately after treatment. Sleep quality, pain symptoms, and psychiatric scores remained improved.

This suggests HBOT may produce lasting neurological changes rather than temporary symptom relief.

Heart function improvements (2023)

Long COVID can affect the heart. A separate randomized controlled trial published in Scientific Reports in 2023 examined myocardial function in post-COVID patients. HBOT improved cardiac metrics in the treatment group, adding cardiovascular recovery to the list of potential benefits.

Systematic reviews confirm the pattern (2024-2025)

Multiple systematic reviews have now examined the cumulative evidence:

• A 2024 clinical review in Frontiers in Medicine analyzed 10 published studies encompassing 284 patients. The review concluded that HBOT provided significant improvement across cognitive, fatigue, and pain domains.

• A 2025 systematic review published in Undersea & Hyperbaric Medicine examined seven studies from seven countries with 199 participants. Memory, executive function, attention, fatigue, and pain all improved with treatment. Side effects were minimal, and none were serious.

Study	Year	Type	Patients	Key Finding
Zilberman-Itskovich et al.	2022	RCT (sham-controlled)	73	Significant cognitive, fatigue, and pain improvement
Hadanny et al.	2024	1-year follow-up	31	Benefits persisted at 1 year
Leitman et al.	2023	RCT	—	Improved myocardial function
Katz et al.	2024	Clinical review	284	Confirmed improvements across studies
Zamora et al.	2025	Systematic review	199	Cognitive and fatigue improvements; minimal side effects

Important limitations to consider

The evidence is promising but not yet conclusive:

• Sample sizes remain small. The largest RCT included only 73 patients. Larger multi-center trials are needed.
• Most studies come from one research group. The Sagol Center in Israel has produced much of the strongest evidence. Independent replication is essential.
• Conflicts of interest exist. Lead researchers have financial ties to AVIV Scientific, a company offering HBOT protocols. This does not invalidate the research, but it warrants transparency.
• Not all studies show dramatic results. The Swedish HOT-LoCO trial using only 10 sessions showed more modest outcomes, suggesting protocol design matters significantly.

For a broader look at the evidence base, visit the FindHBOT research section, which catalogs 40+ verified clinical studies across 15 conditions.

Symptoms that respond to hyperbaric oxygen therapy

Not all Long COVID symptoms respond equally to HBOT. Based on the clinical evidence, these are the symptoms with the strongest support:

Cognitive dysfunction (brain fog)

Brain fog is the symptom most consistently improved in clinical trials. Patients report clearer thinking, better memory recall, and improved concentration. The 2022 RCT showed measurable gains in attention and information processing speed on standardized cognitive tests.

Jennifer, a 45-year-old nurse in Denver, described her experience: she had gone from managing a 20-bed ward to struggling to complete grocery lists. After 40 HBOT sessions, she noticed the mental clarity returning. "It wasn't overnight," she said. "Around session 25, I started finishing sentences again without losing my train of thought."

Chronic fatigue

Fatigue affects roughly 59% of Long COVID patients. HBOT's effect on mitochondrial function may explain the energy improvements researchers have documented. The one-year follow-up study confirmed that fatigue improvements persisted long after treatment ended.

Sleep disturbances

The 2024 follow-up study found moderate-magnitude improvements across five sleep quality domains. Better sleep often correlates with improvement in other symptoms.

Pain

Joint pain, muscle pain, and headaches improved in both the original RCT and the 2025 systematic review. Pain reduction was sustained at the one-year mark.

Psychiatric symptoms

Depression and anxiety scores improved significantly in the treatment groups. Whether this reflects direct neurological effects or is secondary to improved function and sleep remains under investigation.

Symptoms with less evidence

Shortness of breath, exercise intolerance, and autonomic symptoms (like rapid heart rate) have less clinical trial data supporting HBOT as a treatment. These symptoms may improve secondarily as inflammation decreases, but more targeted research is needed.

Treatment protocols: what to expect

If you are considering hyperbaric oxygen therapy for Long COVID, here is what a typical treatment course looks like.

How many sessions?

The most studied protocol uses 40 sessions, administered five days per week over eight weeks. Each session lasts approximately 90 minutes, including pressurization and depressurization time.

Some protocols use fewer sessions. The Swedish HOT-LoCO trial tested just 10 sessions with more modest results. Most clinicians who specialize in neurological applications recommend 20 to 40 sessions for lasting benefit.

Sporadic sessions are generally not effective for chronic Long COVID. Neuroplasticity requires sustained, repeated exposure to create lasting changes in brain tissue.

Pressure and oxygen levels

Protocol Element	Typical Range	Most Studied
Pressure	1.5-2.4 ATA	2.0 ATA
Oxygen concentration	100%	100%
Session duration	60-90 minutes	90 minutes
Air breaks	Every 20 minutes	5-minute breaks
Frequency	5 days/week	5 days/week
Total sessions	20-60	40

What a session feels like

You will enter a hyperbaric chamber, either a monoplace (single-person) or multiplace (group) unit. As pressure increases, you will feel pressure in your ears, similar to airplane descent. Most patients equalize by swallowing or yawning.

During the session, you can read, listen to music, or sleep. Many patients report feeling relaxed. Some experience mild fatigue afterward for the first few sessions.

For a detailed look at chamber types and how they differ, read our guide to types of hyperbaric chambers.

When to expect improvement

Most patients do not notice dramatic changes in the first week. Based on clinical reports:

• Sessions 10-15: Some patients begin noticing subtle improvements in energy and mental clarity
• Sessions 20-30: More consistent cognitive improvements and reduced fatigue
• Sessions 30-40: Maximum benefit for most patients
• Post-treatment: Benefits continue to consolidate and were maintained at one year in the follow-up study

Cost and insurance: what you need to know

This is the difficult conversation. Hyperbaric oxygen therapy for Long COVID is not cheap, and insurance coverage is extremely limited.

Why insurance usually does not cover it

Long COVID is not an FDA-approved indication for hyperbaric oxygen therapy. The FDA recognizes HBOT for 14 specific conditions, including diabetic wounds, radiation injury, and carbon monoxide poisoning. Long COVID is not on that list.

Because it is considered off-label use, most insurance plans, including Medicare and Medicaid, will not cover HBOT for Long COVID. Some patients have successfully appealed denials, particularly when they can demonstrate failed conventional treatments, but this remains the exception.

How much it costs

Costs vary significantly based on location, clinic type, and protocol:

Clinic Type	Cost Per Session	40-Session Course
Independent HBOT clinic	$150-$400	$6,000-$16,000
Hospital-based program	$200-$500	$8,000-$20,000
Specialty wellness center	$250-$600	$10,000-$24,000
Premium integrated program	$900-$1,275	$36,000-$51,000

Many clinics offer package discounts for multi-session purchases. Some offer payment plans or financing options.

For a detailed breakdown of HBOT pricing, read our complete 2026 cost guide, which includes real pricing data from clinics across the country.

Is it worth the investment?

This is a deeply personal decision. For patients like David, a 55-year-old financial advisor in Chicago who had been unable to work for nine months due to brain fog and fatigue, the $12,000 he spent on 40 sessions at a local clinic was, in his words, "the best money I've ever spent." He returned to work within a month of completing treatment.

Others may not have the same results or the financial capacity to make that investment. The research supports real improvements for many patients, but individual outcomes vary.

How to find a Long COVID clinic near you

Not every hyperbaric oxygen therapy clinic treats Long COVID. When searching for a provider, look for:

• Hard-shell chambers operating at 2.0 ATA or higher (matching the researched protocols)
• Physician oversight during sessions
• Experience with neurological conditions (Long COVID, TBI, stroke)
• Willingness to discuss the evidence honestly, including its limitations

The FindHBOT directory includes 143 clinics currently offering HBOT for Long COVID, searchable by location and filterable by chamber type. You can also browse all hyperbaric oxygen therapy clinics to compare options in your area.

Questions to ask a clinic before booking

1. What pressure protocol do you use for Long COVID patients?
2. How many Long COVID patients have you treated, and what outcomes have you seen?
3. Do you offer package pricing or financing?
4. Is there a physician on-site during treatments?
5. What type of chambers do you use (monoplace or multiplace)?

For more guidance on evaluating clinics, see what the research shows about HBOT benefits to understand which outcomes are backed by evidence.

Frequently asked questions

Is hyperbaric oxygen therapy FDA-approved for Long COVID?

No. Hyperbaric oxygen therapy is not FDA-approved for Long COVID. The FDA recognizes HBOT for 14 specific conditions, and Long COVID is not currently among them. Treatment for Long COVID is considered off-label use, which means insurance coverage is typically not available. However, multiple clinical trials have demonstrated significant benefits, and research toward potential future approval is ongoing.

How many HBOT sessions do I need for Long COVID?

Most clinical trials used 40 sessions over eight weeks, administered five days per week at 2.0 ATA. Some patients benefit from fewer sessions (20-30), while more severe cases may require up to 60. The Swedish HOT-LoCO trial tested just 10 sessions with more modest results, suggesting that longer protocols may produce better outcomes for chronic symptoms.

How much does HBOT cost for Long COVID treatment?

Individual sessions range from $150 to $600, with a full 40-session course costing $6,000 to $24,000 depending on clinic type and location. Premium integrated programs that include brain imaging and specialized care can cost $36,000 to $51,000. Many clinics offer package discounts and financing options.

Are there side effects of HBOT for Long COVID patients?

The 2025 systematic review found that side effects were minimal and none were serious. The most common include temporary ear pressure or discomfort (similar to flying), mild fatigue after early sessions, and temporary changes in vision. Serious complications are rare when treatment is administered by trained professionals in properly maintained facilities.

How long do HBOT benefits last for Long COVID?

The 2024 follow-up study tracked patients for one year after completing treatment. Quality of life, sleep, pain, and psychiatric improvements all persisted at the 12-month mark, showing similar magnitude to the improvements measured immediately after treatment. This suggests HBOT may produce lasting neurological changes rather than temporary symptom masking.

The bottom line

The research on hyperbaric oxygen therapy for Long COVID is among the most encouraging developments in a field that has offered patients few effective options. Randomized controlled trials show significant improvements in brain fog, fatigue, sleep, pain, and quality of life. A one-year follow-up confirms these benefits persist.

The treatment is not a guaranteed solution. Sample sizes in clinical trials remain small, the cost is substantial, and insurance rarely covers it. But for the estimated 20 million Americans living with Long COVID symptoms that conventional medicine has struggled to address, HBOT represents a research-backed option worth discussing with a healthcare provider.

Key takeaways:

• Multiple RCTs show significant cognitive, fatigue, and quality-of-life improvements
• Benefits persisted at one year in follow-up studies
• Standard protocol: 40 sessions at 2.0 ATA over eight weeks
• Cost: $6,000-$24,000 for a full course (not typically covered by insurance)
• 143 clinics in the FindHBOT directory currently treat Long COVID

Ready to explore your options? Browse Long COVID clinics near you or search all hyperbaric oxygen therapy clinics in the FindHBOT directory.

Sources

1. Zilberman-Itskovich S, Catalogna M, Sasson E, et al. "Hyperbaric oxygen therapy improves neurocognitive functions and symptoms of post-COVID condition: randomized controlled trial." Scientific Reports. 2022. PubMed

2. Hadanny A, Zilberman-Itskovich S, Catalogna M, et al. "Long term outcomes of hyperbaric oxygen therapy in post covid condition: longitudinal follow-up of a randomized controlled trial." Scientific Reports. 2024. PubMed

3. Leitman M, et al. "The effect of hyperbaric oxygen therapy on myocardial function in post-COVID-19 syndrome patients: a randomized controlled trial." Scientific Reports. 2023. Nature

4. Katz I, et al. "Hyperbaric oxygen effectively addresses the pathophysiology of long COVID: clinical review." Frontiers in Medicine. 2024. Frontiers

5. Zamora E, et al. "Hyperbaric Oxygen Treatment for Long-COVID syndrome: A Systematic Review of Current Evidence on Cognitive Decline." Undersea & Hyperbaric Medicine. 2025. PubMed

6. CDC. "Long COVID Basics." CDC.gov

7. RECOVER COVID Initiative. "RECOVER Research Update." recovercovid.org

This article is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider before starting any treatment, including hyperbaric oxygen therapy.