Post-Ingestion Blood Hydrogen Kinetics Following Oral Hydrogen-Rich Water Intake in Healthy Adults: A Pilot Pharmacokinetic Study.

INTRODUCTION

Molecular hydrogen (H2) has gained attention as a therapeutic agent due to its antioxidant and anti-inflammatory properties. However, human Pharmacokinetic (PK) data remain limited, particularly for Hydrogen-Rich Water (HRW). This study aimed to characterize blood hydrogen kinetics following oral HRW intake in healthy adults.

METHODS

Twelve healthy participants (mean age 28.8 ± 3.8 years; BMI 23.4 ± 3.2 kg/m²; 50% female) were enrolled in the study. After an overnight fast, participants consumed a single dose of HRW. Blood samples were collected at baseline and at multiple time points up to 120 minutes postingestion. Hydrogen concentrations were measured using a Clark-type microsensor. PK parameters were calculated using non-compartmental analysis, and time-dependent changes were assessed using linear mixed-effects modeling.

RESULTS

Baseline hydrogen concentration was 0.25 ± 0.05 μg/L. Peak concentration (Cmax) reached 0.83 ± 0.18 μg/L at 42.9 ± 8.4 minutes (Tmax). The elimination half-life was 144.8 ± 41.7 minutes, and total systemic exposure (AUC₀-∞) was 128.6 ± 27.1 μg/L·min. Hydrogen levels were significantly elevated at 15, 60, and 90 minutes compared to baseline. Notable inter-individual variability was observed, and no sex-related differences were detected.

DISCUSSION: Oral HRW intake resulted in measurable systemic hydrogen exposure, with a biphasic concentration pattern, suggesting rapid absorption possibly followed by redistribution. Observed concentrations approached proposed minimal effective levels but were not sustained, raising questions about optimal dosing strategies.

CONCLUSION

HRW ingestion produces detectable and biologically relevant increases in blood hydrogen levels. These findings support HRW as a viable route of H2 administration and provide a foundation for future studies investigating dosing, kinetics, and therapeutic applications.