GROWTH HORMONE RELEASING FACTOR (GRF) ANALOGUES

Novel growth hormone releasing factor analogs are presented having the formula: s, Tyr, or desNH2Tyr; R2 is Val, Leu, or Ile; R3 is Ala; R4 is Met, Leu, Ile, or Nle; R5 is Ser or Asn; R6 is an amino acid residue sequence selected from Arg-Gln-Gln-Gly-Glu-Ser-Asn-Gln-Glu-Arg-Gly-Ala-Arg-Ala-Arg-Leu or fragments thereof where the fragment is reduced in number by one to fifteen amino acid residues from the amino acid residue which carries the substituent X; and X is either OH or NH2, and the pharmaceutically acceptable acid or base addition salts thereof. The novel growth hormone releasing factor analogs demonstrate enhanced potency for the released growth hormone, have enhanced enzymatic stability, and can be administered to a subject having a deficiency of growth hormone or for improvement of growth performance in livestock.