A peptidic compound having the formula: R 1 - Z - R 2 wherein Z is a peptide moiety having the formula Tyr-Aib-X3-Gly-Thr-Phe-Thr-Ser-Asp-Leu-Ser-X12-Gln-X14-X15-X16-X17-X18-X19-X20-X21-Phe-Ile-Glu-Trp-Leu-Lys-X28-X29-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-Pro-Ser-X40 X3 represents an amino acid residue selected from Gln and His, X12 represents an amino acid residue selected from Ile and Lys, X14 represents an amino acid residue having a side chain with an - NH 2 group, wherein the -NH 2 side chain group is functionalized by - C -R 5, wherein R 5 may be a moiety comprising up to 50 or up to 100 carbon atoms and optionally heteroatoms selected from halogen, N, O, S and/or P, X15 represents an amino acid residue selected from Asp and Glu, X16 represents an amino acid residue selected from Ser, Lys, Glu and Gln, X17 represents an amino acid residue selected from Arg, Lys, Glu, Ile, Gln, Leu, Aib, Tyr and Ala, X18 represents an amino acid residue selected from Ala, Arg, Aib, Leu, Lys and Tyr, X19 represents an amino acid residue selected from Ala, Gln, Val and Aib, X20 represents an amino acid residue selected from Gin, Aib, Phe, Arg, Leu, Lys and His, X21 represents an amino acid residue selected from Asp, Glu, Tyr, and Leu, X28 represents an amino acid residue selected from Asn, Ala, Aib, Arg and Lys, X29 represents an amino acid residue selected from Gly, Thr, Aib, D-Ala and Ala, X40 is either absent or represents Lys, R 1 represents NH 2, R 2 represents the C-terminal group of the peptidic compound and is selected from OH and NH 2, or a salt or solvate thereof, wherein the compound is a GLP-1 and GIP receptor agonist. wherein Z is a peptide moiety having the formula Tyr-Aib-X3-Gly-Thr-Phe-Thr-Ser-Asp-Leu-Ser-X12-Gln-X14-X15-X16-X17-X18-X19-X20-X21-Phe-Ile-Glu-Trp-Leu-Lys-X28-X29-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-Pro-Ser-X40 X3 represents an amino acid residue selected from Gln and His, X12 represents an amino acid residue selected from Ile and Lys, X14 represents an amino acid residue having a side chain with an - NH 2 group, wherein the -NH 2 side chain group is functionalized by - C -R 5, wherein R 5 may be a moiety comprising up to 50 or up to 100 carbon atoms and optionally heteroatoms selected from halogen, N, O, S and/or P, X15 represents an amino acid residue selected from Asp and Glu, X16 represents an amino acid residue selected from Ser, Lys, Glu and Gln, X17 represents an amino acid residue selected from Arg, Lys, Glu, Ile, Gln, Leu, Aib, Tyr and Ala, X18 represents an amino acid residue selected from Ala, Arg, Aib, Leu, Lys and Tyr, X19 represents an amino acid residue selected from Ala, Gln, Val and Aib, X20 represents an amino acid residue selected from Gin, Aib, Phe, Arg, Leu, Lys and His, X21 represents an amino acid residue selected from Asp, Glu, Tyr, and Leu, X28 represents an amino acid residue selected from Asn, Ala, Aib, Arg and Lys, X29 represents an amino acid residue selected from Gly, Thr, Aib, D-Ala and Ala, X40 is either absent or represents Lys, R 1 represents NH 2, R 2 represents the C-terminal group of the peptidic compound and is selected from OH and NH 2, or a salt or solvate thereof, wherein the compound is a GLP-1 and GIP receptor agonist.