Post-Intervention Kinetics of Hydrogen Gas Inhalation: Influence of Variable Exposure Durations

Molecular hydrogen (dihydrogen) has emerged as a promising therapeutic gas with potential benefits for treating various acute and chronic diseases. However, understanding its pharmacokinetics, especially in humans, remains limited. This pilot study aims to assess the pharmacokinetics of inhaled dihydrogen in healthy humans, focusing on the effects of varying exposures on blood dihydrogen concentrations. Five healthy male participants underwent three separate inhalation sessions (15, 30, and 45 minutes) of dihydrogen, with blood levels measured at multiple time points after inhalation. Pharmacokinetic analysis revealed significant differences in the time to maximum concentration (T_max) and the area under the concentration-time curve (AUC) across the different inhalation durations. A 45-minute exposure resulted in a lower T_max and a higher AUC, indicating more substantial systemic dihydrogen exposure. The minimum effective concentration (MEC) of blood dihydrogen following intervention was estimated to fall within the range of 0.42 to 1.05 µg/L. Our findings suggest a dose-response relationship between inhalation duration and hydrogen absorption, offering insights into the optimal dosing and timing for therapeutic applications of inhaled dihydrogen. The study provides preliminary pharmacokinetic data essential for refining dihydrogen-based treatments in clinical settings.