Methods and formulations of modified release amino acids are provided for the treatment or management of diseases defined by impaired amino acid metabolism, with improved pharmacokinetics, metabolism and utilization.本發明提供一種修飾釋放之胺基酸之方法與製劑,其具有改良之藥物動力學、代謝與利用性,用於治療或管理受到胺基酸代謝受損所界定之疾病。