The efficacy of hydrogen/oxygen therapy favored the recovery of omicron SARS-CoV-2 variant infection: results of a multicenter, randomized, controlled trial
Shi MM, Chen YT, Wang XD, et al. · Journal of Clinical Biochemistry and Nutrition. 2023;73(3):228–233.
Study at a glance
Human
Adults aged 18–80 hospitalized with common-type Omicron COVID-19 at seven hospitals in Shanghai.
A mixed H₂/O₂ gas was delivered by nasal cannula at 3 L/min for at least 7 hours/day in addition to standard care. · Total mixed-gas flow 3 L/min. The article identifies an AMS-H-03 generator but does not print the H₂ or O₂ fraction.
At least 7 hours/day during hospitalization; viral conversion was followed through day 10.
Viral shedding averaged 3.3±2.30 versus 4.1±3.12 days (p=0.374); 5-day conversion was 87.5% versus 75%, cumulative conversion p=0.283, and CT resolution p=0.711. Between-arm IL-6 differences were not significant. One fever in the H₂/O₂ arm was judged unrelated; no serious treatment-related event was reported.
Small trial with significant baseline sex and height imbalance, unequal co-treatments, uncertainty about the start of viral positivity and several favorable narrative claims despite null between-arm tests. The device was supplied by Shanghai Asclepius Meditec; public grants were reported and the authors declared no conflict.
What kind of evidence is this?
Human
Multicenter randomized active-controlled parallel trial
Respiratory health
Inhaled H₂
Information not yet classified
Some editorial classification fields are still pending. The source-reported outcomes and result are shown below; Hydrogenology does not infer a positive or negative signal from prose automatically.
Methods
Adults aged 18–80 hospitalized with common-type Omicron COVID-19 at seven hospitals in Shanghai.
64 randomized: H₂/O₂ n=32 and oxygen n=32.
At least 7 hours/day during hospitalization; viral conversion was followed through day 10.
A mixed H₂/O₂ gas was delivered by nasal cannula at 3 L/min for at least 7 hours/day in addition to standard care.
H₂ and O₂ were co-delivered; the article does not state the mixture ratio, so Hydrogenology does not label it Brown's gas.
Total mixed-gas flow 3 L/min. The article identifies an AMS-H-03 generator but does not print the H₂ or O₂ fraction.
Not reported — absolute H₂ flow cannot be calculated without a reported H₂ fraction.
O₂ was co-delivered, but its fraction and absolute flow were not reported.
Oxygen inhalation plus standard care. Concomitant treatment was imbalanced: Paxlovid was used by 17 controls and 8 H₂/O₂ participants; Lianhua Qingwen by 11 and 5; antibiotics by 5 and 2.
Outcomes and reported result
Viral-shedding duration and conversion, inflammatory and lymphocyte measures, chest-CT resolution and adverse events.
Viral shedding averaged 3.3±2.30 versus 4.1±3.12 days (p=0.374); 5-day conversion was 87.5% versus 75%, cumulative conversion p=0.283, and CT resolution p=0.711. Between-arm IL-6 differences were not significant. One fever in the H₂/O₂ arm was judged unrelated; no serious treatment-related event was reported.
The complete PMC and J-STAGE articles, methods, tables, supplementary outcomes, adverse events, funding and conflicts were checked; the principal between-arm findings were not statistically significant.
A reported association, difference or mechanism is not automatically a clinical benefit.
Limitations and applicability
Small trial with significant baseline sex and height imbalance, unequal co-treatments, uncertainty about the start of viral positivity and several favorable narrative claims despite null between-arm tests. The device was supplied by Shanghai Asclepius Meditec; public grants were reported and the authors declared no conflict.
Hospitalized adults with common-type Omicron infection under this 2022 Shanghai protocol; it does not establish benefit for other variants, prevention or severe COVID-19.
No single-study GRADE certainty rating is assigned. Read how records and evidence assessments are prepared.
Sources and record status
PMID: 37970554 · DOI: 10.3164/jcbn.23-32
Free full articles on PMC and J-STAGE.
PMC and J-STAGE full articles plus PubMed and trial metadata; full-text and article-status check completed 8 August 2026.
10 August 2026
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