Abstract: 1,2,3,4,6-Penta-O-Galloyl-β-d-Glucose (PGG) is a hydrolysable tannin that belongs to the group of gallotannins but also participates in the formation of ellagitannins. PGG is composed of five galloyl groups with a glucose at its core and has structural characteristics that confer a high biological power. In this paper, we describe the chemistry of PGG, which is analyzed from a critical point regarding the types of synthesis, new sources of production from plants and by-products, highlighting the PGG obtaining, and its main functional properties recently reported in scientific literature. PGG has attracted attention because of its therapeutic potential and has shown functional properties as antimicrobial, anti-inflammatory, anti-carcinogenic, antidiabetic and antioxidant. Bioconversion from tannic acid can be potentialized with the use of biotechnological techniques. PGG can be obtained from natural sources as by-products. Research should continue to obtain pure molecules, in adequate quantity and with great biological activity.