# Hydrogen: A Potential New Adjuvant Therapy for COVID-19 Patients.
> COVID-19患者における水素の補助的活用の可能性に関する考察


## Abstract

Molecular hydrogen exhibits multiple biological properties including antioxidant activity, anti-inflammatory effects, hormone regulation, and resistance to apoptosis. This review examines the possibility that H2 administration during the early phase of SARS-CoV-2 infection could help suppress excessive cytokine release and associated lung damage, facilitate clearance of viscous secretions, and lower the rate of disease progression to severe stages. The authors note that definitive conclusions regarding efficacy and safety will require confirmation through large-scale clinical investigations.

### Mechanism

H2 may mitigate SARS-CoV-2-induced lung injury by scavenging reactive oxygen species and suppressing the excessive cytokine cascade, while also facilitating sputum clearance through its anti-inflammatory properties.

## Bibliographic

- **Authors**: Yang F, Yue R, Luo X, Liu R, Huang X
- **Journal**: Front Pharmacol
- **Year**: 2020
- **PMID**: [33178011](https://pubmed.ncbi.nlm.nih.gov/33178011/)
- **DOI**: [10.3389/fphar.2020.543718](https://doi.org/10.3389/fphar.2020.543718)
- **PMC**: [PMC7593510](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7593510/)
- **Study type**: review
- **Delivery route**: inhalation
- **Effect reported**: not assessed

## Delivery context

For inhalation applications of molecular hydrogen, the lower flammability limit (LFL) deserves careful handling. The classical 4% figure applies to closed-system mixtures; the practical inhalation-environment threshold is 10%. Even pure-hydrogen output (the UFL 75% paradox) passes through the flammable range at the air–gas boundary. High-concentration (66% / 100%) inhalers are documented in the Japanese Consumer Affairs Agency accident-information database and are not recommended.

## Safety notes

For inhalation applications of molecular hydrogen, the lower flammability limit (LFL) deserves careful handling. The classical 4% figure applies to closed-system mixtures; the practical inhalation-environment threshold is 10%. Even pure-hydrogen output (the UFL 75% paradox) passes through the flammable range at the air–gas boundary. High-concentration (66% / 100%) inhalers are documented in the Japanese Consumer Affairs Agency accident-information database and are not recommended.

See also:
- [Inhalation concentration and LFL / UFL](https://h2-papers.org/en/safety-notes/inhalation-concentration)
- [Consumer Affairs Agency accident cases](https://h2-papers.org/en/safety-notes/accident-cases)
- [LFL / UFL terminology](https://h2-papers.org/en/safety-notes/lfl-ufl-explained)
- [Inhalation safety threshold lineage](https://h2-papers.org/en/safety-notes/lineage)

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> **Cite as**: H2 Papers — PMID 33178011. https://h2-papers.org/en/papers/33178011
> **Source**: PubMed PMID [33178011](https://pubmed.ncbi.nlm.nih.gov/33178011/)