Peptide YY (PYY) also known as peptide tyrosine tyrosine or pancreatic peptide YY_3-36 is a peptide that in humans is encoded by the PYY gene. Peptide YY is a short (36-amino acid) peptide released by cells in the ileum and colon in response to feeding. In the blood, gut, and other elements of periphery, PYY acts to reduce appetite; but when injected directly into the central nervous system, PYY is anorexigenic, i.e., it decreases appetite.

Peptide YY (PYY) also known as peptide tyrosine tyrosine or pancreatic peptide YY_3-36 is a peptide that in humans is encoded by the PYY gene. Peptide YY is a short (36-amino acid) peptide released by cells in the ileum and colon in response to feeding. In the blood, gut, and other elements of periphery, PYY acts to reduce appetite; but when injected directly into the central nervous system, PYY is anorexigenic, i.e., it decreases appetite.