The Clinical Use of Hydrogen as a Medical Treatment

It has been demonstrated that hydrogen molecules possess biological effects, and furthermore, they are colorless, non-toxic, and have a small molecular weight, enabling them to traverse the blood–brain barrier. This review synthesizes more than 100 publications on the use of hydrogen therapy in clinical ailments and categorizes the applications of hydrogen medicine into nine major systemic diseases based on the International Classification of Diseases (ICD)-11. The efficacy of hydrogen therapy is influenced by the in vivo metabolic kinetics associated with different administration routes. In this review, we examine the utilization of hydrogen molecules via various delivery methods and their impact on the treatment of clinical diseases, along with the mechanisms underlying their biological effects.