Dietary Ergothioneine as a Novel Anti‐Aging Nutraceutical: Mechanisms, Bioavailability, and Future Perspectives

ABSTRACT Ergothioneine (EGT), a natural thiol derivative, has gained attention as a geroprotective nutraceutical. Preclinical research shows EGT scavenges free radicals, maintains mitochondrial integrity, slows telomere erosion, and regulates proteostasis via autophagy and senescent cell clearance. Its anti‐inflammatory effects further counteract age‐related tissue dysfunction. However, EGT's exact molecular targets and signaling pathways remain unclear, and challenges in bioavailability, pharmacokinetics, and the clinical validation of aging biomarkers persist. This review synthesizes recent in vitro and in vivo mechanistic insights, early phase human trial outcomes and strategies to enhance EGT delivery and systemic exposure. We identify key unanswered questions on EGT's influence on cellular senescence, proteome stability, and organ‐specific aging and propose a research roadmap to validate its safety and efficacy. By outlining these advances and gaps, we aim to guide both basic scientists and clinicians toward translating EGT into a viable anti‐aging intervention in geriatric medicine.