What Is Hyperbaric Oxygen Therapy (HBOT)? Science, Research & What to Expect

Oxygen is the foundation of cellular life, and most of us never think twice about it. But what if your tissues could access far more of it than normal breathing allows? That's the principle behind hyperbaric oxygen therapy (HBOT): a non-invasive therapy that saturates the body with pure oxygen under pressure, creating conditions that support the body's natural repair and recovery processes at a cellular level.

At Defiant Health, we stay close to the science, and we're excited to offer HBOT as part of our wellness suite. Here's a grounded, research-informed look at what it is, how it works, and what the published literature has found.

What Is Hyperbaric Oxygen Therapy?

Hyperbaric oxygen therapy involves breathing 100% pure oxygen inside a pressurized chamber, typically at 1.5 to 3 times normal atmospheric pressure. Under these conditions, oxygen dissolves directly into blood plasma and other bodily fluids at concentrations well beyond what normal breathing produces, allowing it to reach tissues throughout the body, including areas with compromised circulation.

HBOT has been FDA-cleared for 14 specific medical indications, including diabetic foot ulcers, radiation tissue injury, carbon monoxide poisoning, severe infections, and decompression sickness. A robust and growing body of peer-reviewed research is also examining its applications across brain health, athletic recovery, cellular aging, and more.

How Does HBOT Work?

Normally, oxygen is carried almost entirely by hemoglobin in red blood cells. Under hyperbaric pressure, it also dissolves directly into plasma, dramatically increasing the amount of oxygen available to tissues, including those with reduced blood flow. This shift in oxygen availability sets off a cascade of biological activity that researchers have been studying for decades.

Key mechanisms documented in the scientific literature include:

• Angiogenesis: The stimulation of new blood vessel formation, which supports circulation to areas that need it most
• Stem cell mobilization: Research has documented significant increases in circulating stem cells following HBOT sessions, supporting tissue regeneration
• Inflammatory modulation: HBOT influences pro-inflammatory cytokine pathways, supporting the body's ability to regulate its own inflammatory response
• Collagen and elastin synthesis: Oxygen is a critical input for collagen production, a key factor in wound healing, skin integrity, and connective tissue repair
• Antimicrobial environment: High-oxygen environments are inhospitable to many anaerobic bacteria, supporting the body's natural defenses
• Mitochondrial and neurological support: Research has explored HBOT's relationship to cellular energy production, neuroplasticity, and brain blood flow

Areas of Research & Application

HBOT has both established clinical uses and a growing body of research exploring broader wellness applications. We've noted the distinction so you can see exactly where the science stands.

A Closer Look at the Studies

HBOT is backed by a substantial and growing body of peer-reviewed research, including multiple randomized controlled trials, the gold standard in clinical evidence. Here are some of the most notable published findings.

Long COVID & Post-Viral Cognitive Symptoms

A randomized controlled trial published in Scientific Reports evaluated Long COVID patients who completed 40 HBOT sessions. Researchers documented significant improvements in cognitive function, fatigue, sleep quality, and pain. A one-year longitudinal follow-up confirmed those outcomes held, and brain imaging showed measurable changes in blood flow and tissue health in areas associated with cognition and mood.^[7]

Traumatic Brain Injury & Concussion

A February 2025 double-blind randomized trial in Scientific Reports examined adults with persistent post-concussion symptoms. The HBOT group showed an average 10.6-point improvement on a standardized symptom scale, compared to 3.6 points in the control group, with differences in anxiety, sleep quality, and vestibular symptoms that held at one-year follow-up.^[5]

Stroke & Neuroplasticity

A 2025 bibliometric analysis in Frontiers in Neurology reviewed two decades of HBOT and stroke research, documenting consistent findings around cerebral blood flow improvements and neuroprotective effects. The volume of published research in this area has grown substantially, reflecting increasing scientific interest and investment.^[8]

Cellular Aging Markers

Research published in Frontiers in Aging in 2024 examined HBOT's relationship to key biological aging markers, including telomere length maintenance, stem cell proliferation, angiogenesis, and collagen production. The authors describe HBOT as a compelling area of investigation for regenerative medicine and longevity science.^[1]

Aesthetic & Post-Procedure Recovery

A 2025 systematic review in the Aesthetic Surgery Journal examined HBOT's role in aesthetic medicine, noting its potential to support tissue oxygenation, reduce swelling, and improve healing outcomes following cosmetic procedures.^[3]

What to Expect During a Session

HBOT is straightforward and, for most people, surprisingly relaxing. Here's what a typical session looks like:

1. You enter the chamber — ours is designed for comfort, with space to settle in and unwind.
2. Pressure gradually increases — you'll feel a sensation similar to descending in an airplane. Most people equalize easily by swallowing or yawning. This phase takes about 5–10 minutes.
3. You breathe 100% oxygen — for the main portion of the session (typically 60–90 minutes). Many people read, rest, or simply decompress.
4. Pressure slowly returns to normal — a gradual descent, similar to the ascent phase of a flight.

Most people leave sessions feeling clear-headed and calm. The number of sessions that makes sense for your goals is something we'll work through together during your booking — protocols vary depending on what you're working toward.

Who Explores HBOT?

HBOT draws interest from a wide range of people. Some come with a specific clinical need and a physician referral. Others are proactively investing in recovery, performance, or longevity. Common reasons people explore HBOT include:

• Supporting recovery from surgery, injury, or an aesthetic procedure
• Athletic performance and faster recovery from intense training
• Proactive longevity and cellular health support
• Persistent fatigue, brain fog, or post-viral symptoms
• Cognitive wellness and brain health optimization
• A physician referral for an FDA-cleared indication

HBOT is generally not recommended for individuals who are pregnant or who have certain contraindications, such as untreated pneumothorax. Our team will review your health history before your first session.

Safety & Side Effects

HBOT has a well-established safety profile when administered by a qualified provider. Side effects are typically mild and temporary:

• Ear pressure or discomfort — similar to flying; easily managed by swallowing or yawning
• Sinus congestion or pressure — brief and typically resolves after the session
• Temporary changes in near vision — occasionally reported with extended protocols; resolves over time
• Claustrophobia — some individuals find enclosed spaces uncomfortable; our team is trained to support you through this

Serious adverse events are rare. Your provider will review your health history before your first session to confirm HBOT is appropriate for you.

Frequently Asked Questions