HBOT Frequency · Session Number · Programme Planning
How Many HBOT Sessions Do You Need?
One of the most common questions about Hyperbaric Oxygen Therapy is also one of the hardest to answer with a single number.
There is no universal number of HBOT sessions that is right for everyone.
Session number depends on why HBOT is being explored, the chamber and pressure used, the oxygen exposure, the research or clinical protocol being followed, how frequently sessions are completed and your individual circumstances.
The Short Answer
HBOT Is Not One Universal Protocol
It can be tempting to search for a number such as “10 sessions”, “20 sessions” or “40 sessions” and assume that is the standard HBOT programme.
It isn't.
Research protocols differ substantially depending on what researchers are studying. Pressure can differ. Session duration can differ. Frequency can differ. The total number of exposures can differ.
That means the useful question is not simply: “How many HBOT sessions should everyone have?”
It is: “What type of HBOT programme makes sense for the reason I am considering it?”
One Session vs Repeated Sessions
Trying HBOT Once Is Different From Following a Programme
One Session
Experience HBOT
A single session allows you to experience the chamber, understand pressurisation, see how you tolerate the session and speak with ReWell about whether further HBOT is something you want to explore.
Repeated Sessions
Follow a Structured Programme
Many research studies use repeated HBOT exposures because they are examining physiological and clinical responses that may develop across a course of sessions rather than during one isolated exposure.
That does not mean everybody should automatically complete a long programme. It means that one exposure and a repeated research protocol are answering different questions.
What Determines Frequency?
Six Things That Can Change the Number of Sessions
What Does Research Actually Do?
There Is No Single “Research Dose” of HBOT
Looking at published studies makes the variation very clear. Different conditions and research questions have used very different programmes.
Sessions Across Seven Studies
A 2025 systematic review included 199 participants. HBOT protocols ranged from 10 to 60 sessions and used pressures from 2.0 to 2.5 ATA.
PMID 41223394 →Sessions Over 8–16 Weeks
Thirty participants completed 40 HBOT sessions. Completion time ranged from eight to sixteen weeks, illustrating how pacing can also differ between individuals.
PMID 42249466 →Sessions Over 12 Weeks
A randomised trial in adults with persistent symptoms following non-stroke brain injury used 40 HBOT sessions over a 12-week period.
PMID 40011516 →Important: These figures describe individual research protocols. They are not universal recommendations for every person with Long COVID, ME/CFS, brain injury or another condition.
A Different Example
Sports Research Shows Why Protocol Details Matter
Sports-recovery research provides another useful example because protocols may be structured around exercise and recovery rather than a long clinical course.
A 2026 systematic review and meta-analysis included 10 articles and 299 participants. The studies varied by pressure, intervention duration and athlete group. Both pressures above and at or below 2.0 ATA were represented, and 60-minute and 100-minute intervention durations were analysed separately.
The point is not that athletes should follow one particular session count. It is that pressure, session duration, timing and purpose all form part of the protocol.
Read the sports-recovery research — PMID 40784513 →
“The number should follow the purpose of the programme — not the other way around.”
Avoid the Magic Number
More Sessions Are Not Automatically Better
Seeing 40 sessions in a published study does not mean that 40 is automatically the correct number for everyone.
Likewise, a shorter course should not automatically be considered ineffective simply because another study used more exposures.
Pressure, oxygen exposure, session duration, frequency, study population and purpose all matter.
This is also why protocols from one condition should not simply be copied across to another.
How Will You Access HBOT?
Frequency Also Changes the Practical Decision
Once a programme involves repeated sessions, the question is not only how many — it is also how realistically you can complete them.
New to HBOT
Try in Clinic
If you're simply curious or want to experience HBOT before deciding what comes next, ReWell's Naas clinic is the easiest starting point.
Book Your First Session →Frequent Sessions
Rent at Home
If your planned programme involves regular sessions, home access can remove repeated travel and allow sessions to fit more naturally around everyday life.
Explore Home Rental →Long-Term Access
Own Your Chamber
For longer-term, multi-user or professional use, chamber ownership may become the more practical way to maintain ongoing access.
Explore Ownership →
The ReWell Approach
Start With Why You Are Exploring HBOT
ReWell's HBOT programmes are guided by Davitt Meenaghan, IBUM-certified Hyperbaric Safety Officer.
“There isn't one number of sessions I give everybody. We start with why you're exploring HBOT, what the relevant evidence looks like and what level of access is realistic for you.”
From there, Davitt can talk you through chamber pressure, session frequency, pacing and whether clinic sessions or home access are likely to make more practical sense.
ReWell's goal is not to sell every person the same fixed package. It is to build the HBOT pathway around the individual and the reason they are considering it.
Speak With Davitt →Common Questions
HBOT Session FAQs
How many HBOT sessions do most people need?
There is no single number that applies to most people. Published protocols vary considerably depending on the condition or purpose being studied, chamber pressure, session duration and frequency. ReWell therefore looks at the individual circumstances and relevant evidence rather than prescribing a universal session count.
Is one HBOT session enough?
One session can be useful if your goal is simply to experience HBOT and see how the chamber feels. Research investigating longer-term outcomes commonly uses repeated sessions, so one introductory visit and a structured HBOT programme are different things.
Why do some HBOT programmes use 40 sessions?
Forty sessions appears in some published research protocols, including studies involving ME/CFS and persistent symptoms after brain injury. That does not make 40 sessions a universal HBOT recommendation. Other research has used substantially shorter or longer programmes.
Can HBOT be done every day?
Some research and clinical protocols use sessions on consecutive weekdays or several times per week, while others use different pacing. Appropriate frequency depends on the purpose, pressure, protocol, individual tolerance and relevant medical guidance.
How long is an HBOT session?
ReWell notes that sessions commonly last around 60–90 minutes, although duration can vary according to the chamber and programme. Research protocols also use different exposure times.
Does a higher ATA mean I need fewer sessions?
Not necessarily. Higher pressure does not create a simple formula where fewer sessions are automatically required. Pressure, oxygen exposure, session duration, frequency and purpose all need to be considered together.
Is it easier to complete frequent HBOT sessions at home?
For many people it can be. If a programme involves regular sessions, having a chamber at home removes repeated travel and allows sessions to fit more easily around daily life. ReWell offers one, two and three-month soft-shell home rental options throughout Ireland.
How do I know what programme is right for me?
Start by defining why you are considering HBOT. ReWell can then look at your circumstances, the relevant research, chamber options and what frequency is practically realistic before discussing a programme with you.
Don't Start With a Magic Number
Start With the Reason You Want to Use HBOT
Try HBOT in ReWell's Naas clinic, explore regular home access, or speak with Davitt about what the research and practical options may look like for your circumstances.
This article is for general educational purposes and does not prescribe a specific HBOT protocol or number of sessions. Research protocols should not be interpreted as individual treatment recommendations. HBOT may not be suitable for everyone, and screening, medical history, chamber type, pressure and individual circumstances should be considered before starting.