Small human studies show positive signals for HBOT on telomere length, senescent immune cells, and cerebral blood flow, but all of these studies have methodological limitations and are partly funded by commercial parties. Systematic reviews conclude that the evidence is too thin for practical application. Large, independent randomised trials are still entirely lacking.
Hyperbaric oxygen therapy (HBOT) involves breathing inside a sealed chamber under increased air pressure, allowing the body to absorb more oxygen than usual. It has been used in mainstream medicine for years to treat conditions such as wound healing and diving accidents. In recent years, interest in HBOT as an anti-ageing treatment has been growing, but the evidence for this is still at an early stage.
The most-cited research in this field is a small prospective study of 35 healthy people aged 64 and older who underwent 60 HBOT sessions1. Afterwards, telomeres -- the protective ends of chromosomes that shorten with age -- were more than 20% longer in several types of blood cells. In certain immune cells (B-cells), the increase was as much as 37.6%. At the same time, the number of aged immune cells (senescent T-cells) decreased by 11 to 37%. These are striking figures, but the study had no control group, meaning other factors could explain the results. In addition, several authors have financial ties to a commercial HBOT company, which gives reason for caution when interpreting the findings.
For brain health, there are also early but preliminary indications. A 2021 study showed that HBOT improved cerebral blood flow and reduced amyloid deposits (a hallmark of Alzheimer's disease) in mice with Alzheimer's-like abnormalities. A small group of older people with memory loss also showed increased cerebral blood flow and improved cognitive scores after HBOT2. However, the groups were small and here too some authors held shareholdings in an HBOT company. These are therefore preliminary indications, not evidence that HBOT treats Alzheimer's disease or memory loss.
In the area of skin ageing, an evidence-based review from 2024 covering 17 studies with a total of 766 participants found indications of improved collagen density and more elastin fibres after HBOT, along with a reduction in inflammatory markers3. However, all studies involved had a high risk of bias, meaning the results may appear more favourable than they actually are.
A broader systematic review from 2024 on HBOT in aesthetic medicine and anti-ageing found only 15 studies that met the inclusion criteria and concluded that the evidence is too thin to justify the costs; large, independent randomised trials are lacking4. Even for dry mouth following cancer treatment, a condition for which HBOT is sometimes considered, the evidence is limited and contested5. In short: HBOT as an anti-ageing treatment is biologically interesting and shows some positive signals in small studies, but large, independent, and well-controlled studies demonstrating that it actually delivers real-world benefits are still absent.
All claims are based on small human studies without a control group, animal studies, or systematic reviews that themselves conclude the evidence is insufficient. Several studies disclose financial interests of authors in commercial HBOT providers. The total number of participants in human studies is limited (35 in the telomere study, 766 spread across 17 skin studies, small numbers in the cognition study).