# Molecular Hydrogen Therapy-A Review on Clinical Studies and Outcomes.
> 分子状水素の臨床試験および研究成果に関するレビュー：現状と展望


## Abstract

This review examined 81 clinical trials and 64 human studies to evaluate the potential of molecular hydrogen (H2), which possesses antioxidant properties, across a wide spectrum of disease conditions. Medical database searches yielded over 2000 publications on H2 as a candidate drug substance, and clinical trial registries revealed numerous ongoing investigations. Favorable outcomes were identified in cardiovascular disease, oncology, respiratory conditions, central nervous system disorders, and infectious diseases, among others. The review also addressed practical challenges associated with H2 administration, including its explosive nature and limited aqueous solubility, and discussed emerging technologies designed to overcome these barriers. The authors considered whether H2 may eventually be recognized as a novel pharmaceutical agent, and what delivery forms and clinical indications might be most appropriate for future use.

### Mechanism

H2 acts as a selective antioxidant, preferentially scavenging highly reactive oxygen species such as hydroxyl radicals and peroxynitrite, thereby reducing oxidative damage without disrupting normal redox signaling.

## Bibliographic

- **Authors**: Johnsen HM, Hiorth M, Klaveness J
- **Journal**: Molecules
- **Year**: 2023 (2023-11-26)
- **PMID**: [38067515](https://pubmed.ncbi.nlm.nih.gov/38067515/)
- **DOI**: [10.3390/molecules28237785](https://doi.org/10.3390/molecules28237785)
- **PMC**: [PMC10707987](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10707987/)
- **Study type**: review
- **Delivery route**: mixed routes
- **Effect reported**: positive

## Delivery context

This study combines multiple delivery routes. As a general principle, the most efficient route for routine hydrogen intake is inhalation. Inhalation carries explosion risk (empirical LFL of 10%; high-concentration devices are documented in the Consumer Affairs Agency accident database and are not recommended).

## Safety notes

This study combines multiple delivery routes. As a general principle, the most efficient route for routine hydrogen intake is inhalation. Inhalation carries explosion risk (empirical LFL of 10%; high-concentration devices are documented in the Consumer Affairs Agency accident 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)
- [Inhalation safety threshold lineage](https://h2-papers.org/en/safety-notes/lineage)

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> **Cite as**: H2 Papers — PMID 38067515. https://h2-papers.org/en/papers/38067515
> **Source**: PubMed PMID [38067515](https://pubmed.ncbi.nlm.nih.gov/38067515/)