Hydrogen as an innovative nootropic in health and disease.

Molecular hydrogen (H 2 , dihydrogen) is an antioxidant and signaling molecule with potent antioxidative, antiapoptotic, and anti-inflammatory properties. Despite the growing interest in H2 as a potential therapeutic agent, the evidence regarding its potential as a nootropic remains limited. Only a handful of studies on the human population have evaluated its effects, although there are suggestive indications of its efficacy. The present paper overviews H 2 's potential as a novel agent for improving cognitive functions in health and disease contexts, highlighting its mechanisms of action and areas for further investigation. Current evidence suggests that H 2 improves executive function, alertness and memory in several clinical trials, from healthy young and elderly individuals to individuals with altered circadian rhythms, neurodegenerative disorders, and cancer. Further investigations are needed to confirm the potential positive effects of dihydrogen as a nootropic agent in both health and disease.