TLDR

Long COVID — the persistent syndrome affecting an estimated 10–30% of COVID-19 survivors — causes debilitating fatigue, brain fog, cognitive impairment, breathlessness, and post-exertional malaise that can last months or years. A 2022 randomized controlled trial published in Nature demonstrated that HBOT significantly improved cognitive function, fatigue, quality of life, and pain in Long COVID patients — with measurable brain imaging changes confirming the biological effect. At OxygenWell in Sherman Oaks and Calabasas, we offer evidence-based HBOT protocols for Long COVID guided by the latest clinical research.

Table of Contents

• What Is Long COVID?
• The Biology of Long COVID: Why Symptoms Persist
• How HBOT Addresses Long COVID at the Biological Level
• Clinical Evidence: The Nature RCT and PubMed Research
• What to Expect at OxygenWell
• Frequently Asked Questions

What Is Long COVID?

Long COVID (Post-Acute Sequelae of SARS-CoV-2, or PASC) refers to new, recurring, or persistent symptoms that continue more than four weeks after acute COVID-19 infection. The WHO estimates that 10–20% of COVID-19 survivors develop some form of Long COVID — representing tens of millions of people worldwide.

The most commonly reported symptoms include:

• Profound fatigue and post-exertional malaise (PEM)
• Brain fog — difficulty concentrating, memory problems, slow thinking
• Headache and migraine
• Breathlessness and reduced exercise tolerance
• Sleep disturbances
• Anxiety and depression
• Chest pain and palpitations
• Joint and muscle pain
• Sensory disturbances (tinnitus, visual changes, tingling)

Long COVID does not have an approved pharmacological treatment as of 2026. Most patients receive symptom management rather than targeted biological therapy. This is where HBOT has emerged as a meaningful clinical option.

The Biology of Long COVID: Why Symptoms Persist

1. Cerebral Hypoperfusion and Microclotting

SARS-CoV-2 causes endothelial damage — injury to blood vessel linings throughout the body including the brain. This leads to microthrombi and reduced cerebral blood flow, starving neurons of oxygen and impairing cognitive function. SPECT imaging in Long COVID patients consistently shows reduced cerebral perfusion, particularly in the frontal cortex and hippocampus. [Abeles RD et al., Eur J Neurol. 2022]

2. Mitochondrial Dysfunction

COVID-19 directly impairs mitochondrial function in multiple cell types. Reduced mitochondrial ATP production explains the profound fatigue and post-exertional malaise characteristic of Long COVID — cells simply cannot generate the energy they need to function normally.

3. Persistent Neuroinflammation

Activated microglia and systemic inflammatory cytokines persist in many Long COVID patients long after viral clearance, driving ongoing neurological symptoms, cognitive impairment, and mood changes.

How HBOT Addresses Long COVID at the Biological Level

• Restores cerebral oxygenation: Plasma-dissolved oxygen at 2.0 ATA reaches brain tissue through compromised vasculature, compensating for COVID-19 microvascular damage
• Stimulates angiogenesis: New blood vessel growth via VEGF restores cerebral perfusion over the course of treatment
• Restores mitochondrial function: HBOT increases mitochondrial membrane potential and ATP production, directly addressing the energy deficit underlying fatigue and PEM
• Reduces neuroinflammation: HBOT down-regulates NF-κB and reduces TNF-α, IL-1β, and IL-6 in the brain and systemically
• Promotes neuroplasticity: BDNF upregulation supports cognitive recovery and neural repair

Clinical Evidence: The Nature RCT and PubMed Research

Zilberman-Itskovich et al. — Randomized Controlled Trial (Nature, 2022)

The most significant clinical trial of HBOT for Long COVID was published in Nature in 2022. Eighty Long COVID patients were randomized to 40 HBOT sessions at 2.0 ATA or a sham control. The HBOT group showed statistically significant improvements in:

• Global cognitive function (+16.7% vs. −0.8% in sham)
• Attention, information processing speed, and executive function
• Fatigue severity (significant reduction)
• Sleep quality, pain interference, and psychiatric symptom burden

Brain SPECT imaging confirmed significant increases in cerebral blood flow in frontal, parietal, and temporal lobes — objective evidence of measurable neurobiological change. [Zilberman-Itskovich S et al., Sci Rep (Nature). 2022]

Hadanny et al. — Long COVID Brain Perfusion

A companion study confirmed that cognitive improvements correlated with objective increases in cerebral blood flow on SPECT imaging — particularly in regions associated with attention, working memory, and executive function. [Hadanny A et al., Front Aging Neurosci. 2022]

Fischer et al. — Fatigue and Exercise Tolerance

A study reported significant improvements in fatigue scores, exercise capacity, and quality of life in Long COVID patients following 10 HBOT sessions. [Fischer A et al., Clin Transl Med. 2023]

What to Expect at OxygenWell

OxygenWell is a physician-owned HBOT center in Sherman Oaks and Calabasas, CA, founded and led by Dr. Beth Meneley, DAOM, L.Ac. Dr. Meneley integrates HBOT with functional medicine, red light therapy, NAD+ IV, and hydrogen inhalation to address Long COVID comprehensively — targeting the metabolic and inflammatory terrain, not just surface symptoms.

Our Long COVID HBOT Protocol

• Pressure: 1.5–2.0 ATA
• Session length: 60–90 minutes
• Frequency: 5 days per week
• Total sessions: 40 sessions (RCT-validated); extended courses available
• Oxygen: 100% medical-grade, high-flow delivery

Complementary Therapies at OxygenWell

• NAD+ IV: Restores mitochondrial NAD+ depleted by COVID-19
• Red light therapy: Supports mitochondrial recovery and reduces systemic inflammation
• Hydrogen inhalation: Selective antioxidant targeting COVID-related oxidative stress
• Functional medicine evaluation: Root-cause assessment of factors perpetuating symptoms

HBOT for Long COVID is an off-label use and is not currently covered by Medicare or most PPO plans. Self-pay rates and packages available.

Frequently Asked Questions

How quickly does HBOT help Long COVID symptoms?

Many patients notice improvements in energy, sleep, and mental clarity within the first 10–20 sessions. The full 40-session protocol produced the most significant results in the Nature RCT.

Does HBOT help with Long COVID brain fog?

Yes. The Nature 2022 RCT showed statistically significant improvements in global cognitive function, attention, and information processing speed — the core deficits of Long COVID brain fog — confirmed by SPECT imaging showing increased cerebral blood flow.

Is HBOT covered by insurance for Long COVID?

Long COVID is not currently FDA-approved for HBOT, so it is not covered by Medicare or most PPO plans. Self-pay rates and packages are available. Call us at (818) 661-0939.

Schedule a Consultation at OxygenWell

• Sherman Oaks: 15301 Ventura Blvd., Suite P12, Sherman Oaks, CA 91403
• Calabasas: 23500 Park Sorrento, A2, Calabasas, CA 91302
• Phone: (818) 661-0939
• Website: oxygenwell.com

Written by Dr. Beth Meneley, DAOM, L.Ac. — Founder of OxygenWell. 25+ years in integrative and functional medicine. 12+ years dedicated to hyperbaric medicine in Los Angeles. Over 50,000 HBOT sessions administered under her clinical direction.