# [Different types of molecular hydrogen donors and their pharmacokinetics in vivo].
> 水素分子ドナーの種類と体内薬物動態に関する総説


## Abstract

Molecular hydrogen (H₂) is a small gaseous molecule with documented biomedical properties, capable of diffusing readily into biological tissues. Multiple administration routes have been developed for research and public health applications, including inhalation of H₂ gas, oral intake of hydrogen-rich water, intravenous or intraperitoneal injection of hydrogen-rich saline, oral solid-state sustained-release formulations, and promotion of endogenous H₂ production via intestinal microbiota. Each route produces distinct pharmacokinetic profiles in vivo, which in turn modulate the magnitude and duration of biological effects. This review systematically categorizes the principal H₂ donor types and compares their respective in vivo pharmacokinetic characteristics, providing a framework for understanding how delivery method influences H₂ bioavailability and efficacy.

### Mechanism

As a small-molecule gas, H₂ diffuses freely into tissues. Its pharmacokinetic behavior—including peak concentration, distribution, and clearance—varies substantially depending on the delivery route (inhalation, oral water, injection, solid sustained-release, or gut microbial production), thereby affecting the extent and duration of its biomedical effects.

## Bibliographic

- **Authors**: Liu B, Qin S
- **Journal**: Sheng Li Xue Bao
- **Year**: 2019 (2019-04-25)
- **PMID**: [31008498](https://pubmed.ncbi.nlm.nih.gov/31008498/)
- **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 31008498. https://h2-papers.org/en/papers/31008498
> **Source**: PubMed PMID [31008498](https://pubmed.ncbi.nlm.nih.gov/31008498/)