[Different types of molecular hydrogen donors and their pharmacokinetics in vivo].

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.