# The evolution of molecular hydrogen: a noteworthy potential therapy with clinical significance.
> 分子状水素の医学的可能性：細胞レベルの作用機序と臨床的意義に関する総説


## Abstract

Molecular hydrogen (H2) possesses distinctive physicochemical properties that allow it to penetrate the blood-brain barrier, enter mitochondria, and under specific conditions translocate into the nucleus. Within these subcellular compartments, H2 has been shown across multiple studies to exert antioxidant, anti-apoptotic, anti-inflammatory, and cytoprotective effects. Various administration routes have been explored, including gas inhalation, hydrogen-enriched water, and hydrogen-rich saline, each with a favorable safety profile. This review comprehensively examines the accumulated evidence supporting H2's potential role in addressing cardiovascular, cerebrovascular, oncological, metabolic, and respiratory conditions, while also identifying methodological gaps and unresolved questions that warrant further investigation.

### Mechanism

H2 crosses the blood-brain barrier and enters mitochondria and the nucleus, where it exerts antioxidant, anti-apoptotic, anti-inflammatory, and cytoprotective effects at the subcellular level.

## Bibliographic

- **Authors**: Dixon BJ, Tang J, Zhang JH
- **Journal**: Med Gas Res
- **Year**: 2013 (2013-05-16)
- **PMID**: [23680032](https://pubmed.ncbi.nlm.nih.gov/23680032/)
- **DOI**: [10.1186/2045-9912-3-10](https://doi.org/10.1186/2045-9912-3-10)
- **PMC**: [PMC3660246](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3660246/)
- **Study type**: review
- **Delivery route**: mixed routes
- **Effect reported**: not assessed

## 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 23680032. https://h2-papers.org/en/papers/23680032
> **Source**: PubMed PMID [23680032](https://pubmed.ncbi.nlm.nih.gov/23680032/)