The invention relates to protracted peptide derivatives such as Glucagon-Like Peptide-1 (GLP-1), exendin-4, and analogues thereof, as well as therapeutic uses thereof.The peptide derivative of the invention comprises a peptide wherein at least one amino acid residue is derivatized with A-B-C-, or A-B-C-D-. These compounds are useful in the treatment or prevention of diabetes type 2 and related diseases. The compounds are potent, have a low ratio of binding affinity to the GLP-1 receptor in the presence of high/low albumin concentrations, have long half-lives, and have a high affinity of binding to albumin, all of which is of potential relevance for the overall aim of achieving long- acting, stable and active GLP-1 derivatives with a potential for once weekly administration.