What HBOT is
Hyperbaric oxygen therapy (HBOT) has a person breathe close to 100% oxygen inside a chamber pressurised above sea-level pressure. This sharply increases the amount of oxygen dissolved in the blood and tissues.
Established medical uses
HBOT is an evidence-based, approved treatment for a defined set of conditions — including decompression sickness, carbon-monoxide poisoning, non-healing diabetic wounds and certain infections. In those indications the benefit is well established.
The longevity claim
A separate, much newer idea is that repeated HBOT sessions might slow or reverse aspects of ageing. A small 2020 trial in healthy older adults reported increased telomere length and fewer senescent immune cells after a course of sessions. This is intriguing but preliminary: the study was small, lacked a robust control for many factors, and used surrogate markers rather than health outcomes. We therefore rate the *anti-ageing* use Experimental.
What to ask a clinic
Ask whether your goal is an established indication or an off-label “longevity” protocol, how many sessions and at what pressure, and what evidence supports the specific claim being made. HBOT also has real contraindications (e.g. certain lung conditions), so medical screening matters.