Hyperbaric oxygen
Mixed findingsWhy it might help
Breathing near-100% oxygen under increased pressure raises tissue oxygenation; researchers hypothesize this may reduce neuroinflammation, improve cerebral blood flow and endothelial function, and support neuroplasticity.
What the research shows
Small sham-controlled trials of hyperbaric oxygen have reported improvements in cognition, fatigue, sleep, and pain in some people with long COVID, but a later placebo-controlled trial using far fewer sessions found no benefit over sham. The evidence is genuinely mixed and far from settled.
Sources & what they found (2)
Hyperbaric oxygen therapy improves neurocognitive functions and symptoms of post-COVID condition: randomized controlled trial — Scientific Reports (PMC), 2022
Randomized, double-blind, sham-controlled trial (73 participants, 40 sessions) reporting improved cognition, fatigue, sleep and pain interference.
Ten sessions of hyperbaric oxygen versus sham in patients with long covid (HOT-LoCO): a randomised, placebo-controlled, double-blind, phase II trial — eClinicalMedicine (PMC), 2025
Placebo-controlled trial (10 sessions) that found no short-term benefit over sham, with both groups improving.



