?What are proposed are: synthetic peptides having a non-narcotic type of analgesic effect, of general formula 1 [SEQ ID NO:1], where: H is hydrogen, XDL is an omission of an amino acid or is L-Tyr, XDL1 is one of the following amino acids: L-Leu, L-Ala or D-Ala, XDL2 is one of the following amino acids: L-His, D-His, L-Ala or D-Ala, XDL3 is one of the following amino acids: L-Gln, L-Ala or D-Ala； R2 is ??? or NH2, and also retro-inversion peptides of formula (I), having a reverse sequence of amino acids with L-shaped amino acids being substituted by D-shaped amino acids, and D-shaped amino acids being substituted by L-shaped amino acids, of general formula 2 [SEQ ID NO:2], where: H is hydrogen, XDL4 is one of the following amino acids: D-GIn, D-Ala or L-Ala, XDL5 is one of the following amino acids: D-His, L-His, D-Ala or L-Ala, XDL6 is one of the following amino acids: D-Leu, D-Ala or L-Ala, XDL7 is an omission of an amino acid or is D-Tyr, R2 is ??? or NH2.
