Hydrolyzed yeast extract is a hydrolysate of yeast extract derived by acid, enzyme, or other methods of hydrolysis. It is added to skin care products because it contains a mixture of flavonoids, sugars, vitamins, and amino acids. The essential amino acids and small peptides in hydrolyzed yeast extract are thought to help skin achieve a brighter tone by targeting melanocytes. A melanocyte is a type of cell that produces melanin, the pigment that gives skin color. With age, melanocytes can become erratic and overproduce pigments that lead to dark spots.