Molecular hydrogen content of different dietary supplements

Abstract

Molecular hydrogen (H 2 , dihydrogen) is an innovative bioactive non-nutrient with diverse applications in experimental and clinical nutrition (Ostojic 2019;Artamonov et al. 2023;Ramanathan et al. 2023;Todorovic et al. 2023;Xie et al. 2023). Dihydrogen is commonly available in various dietary supplements, including ready-to-consume liquid solutions, capsules, orally disintegrating tablets, and effervescent powders and tablets (Ohta 2014). Many manufacturers of dihydrogen supplements anecdotally claim that their products are highly saturated with gaseous hydrogen, with concentrations exceeding 500 µmol•L -1 [~ 1 ppm (parts per million)], a threshold often considered critical for the biological effects of dihydrogen. However, human studies not revealed exact concentrations (mass per unit volume) required for the biological effects of dihydrogen in human nutrition. The only standard proposed thus far is by the International Hydrogen Standards Association (IHSA, http://www.intlhsa.org), indicating a minimum concentration of 250 µmol•L -1 . Nonetheless, it remains unclear whether supplements available on the market actually deliver a dihydrogen concentra-