A peptide antagonist related to the calcitonin gene having the structure of Formula I: X1-Y1-Z1 (I), wherein X1 comprises X11-X12-X13-X14-X15-X16-X17 (SEQ ID NO : 16), in which X11 is selected from the group consisting of alanine (Ala), cysteine (Cys) and glycine (Gly), and in which X12 is selected from the group consisting of cysteine (Cys) and serine (Ser ), provided that one of X11 and X12 is Cys； X13 is selected from the group consisting of arginine (Arg), asparagine (Asn), aspartic acid (Asp) and valine (Val)； X14 is selected from the group consisting of leucine (Leu), phenylalanine (Phe) and threonine (Thr)； X15 is selected from the group consisting of alanine (Ala), glycine (Gly) and serine (Ser)； X16 is selected from the group consisting of alanine (Ala), isoleucine (Ile), leucine (Leu) and serine (Ser)； X17 is Cys； and in which Y1 is -Val-Leu-Gly-Arg-Leu-Ser-Gln-Glu-Leu-His-Arg-Leu-Gln-Thr-Tyr-Pro-Arg-Thr-Asn- (SEQ ID NO: 3. 4)； and Z1 is -Val-Gly-Ser-Lys-Ala-Phe-NH2 (SEQ ID NO: 46).Un antagonista del péptido relacionado con el gen de la calcitonina que tiene la estructura de Fórmula I: X1-Y1-Z1 (I), en la que X1 comprende X11-X12-X13-X14-X15-X16-X17 (SEQ ID NO: 16), en la que X11 se selecciona del grupo que consiste en alanina (Ala), cisteína (Cys) y glicina (Gly), y en la que X12 se selecciona del grupo que consiste en cisteína (Cys) y serina (Ser), siempre que uno de X11 y X12 sea Cys； X13 se selecciona del grupo que consiste en arginina (Arg), asparagina (Asn), ácido aspártico (Asp) y valina (Val)； X14 se selecciona del grupo que consiste en leucina (Leu), fenilalanina (Phe) y treonina (Thr)； X15 se selecciona del grupo que consiste en alanina (Ala), glicina (Gly) y serina (Ser)； X16 se selecciona del grupo que consiste en alanina (Ala), isoleucina (Ile), leucina (Leu) y serina (Ser)； X17 es Cys； y en la que Y1 es -Val-Leu-Gly-Arg-Leu-Ser-Gln-Glu-Leu-His-Arg-Leu-Gln-Thr-Tyr-Pro-Arg-Thr-Asn- (SEQ ID NO: 34)； y Z1 es -Val-Gly-Ser-Lys-Ala-Phe-NH2 (SEQ ID N
