Provided is a modified human FGF-21 polypeptide comprising a non-naturally encoded amino acid, wherein the non-naturally encoded amino acid has a structure attached to the amino terminal which is any substituent other than a side chain found in alanine, arginine, asparagine, aspartic acid, cysteine, glutamine, glutamic acid, glycine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, pyrrolysine, or selenocysteine, and wherein the non-naturally encoded amino acid is substituted at a position selected from the group consisting of residues 72, 77, 86, 87, 91, 104, 108, 110, 126, 131, and 146.
