Ergothioneine is a rare amino acid, which is newly proposed as a putative longevity vitamin and has gained attention because of its antioxidant properties.

It has a potential benefit for different ROS-related risks, including ultraviolet (UV)-induced skin aging, neurodegenerative disorders (Alzheimer’s and Parkinson’s diseases), depression, cataract, and cardiovascular diseases.

Ergothioneine is also safe for humans and stable in heat or acidic environments. Therefore, it has broad applicability for skincare products, supplements, and food additives as well as pharmaceutical products.

This handbook highlights its physical properties and function.