Chinese gallotannin, derived from Galla Chinensis, is a non-specific promiscuous inhibitor of various enzymes. It is a potent inhibitor of human salivary α-amylase, with a Ki value of 0.82 μg/mL. Mechanistic studies reveal that gallotannins exert their inhibitory effects through the formation of aggregates, which serve as the active species in the inhibition process. Beyond its role in carbohydrate metabolism, it exhibits inhibitory activity against telomerase, fatty acid synthase, and 5α-reductase, making it a versatile tool for research in diabetes, oncology, and metabolic disorders.