A peptidic compound having the formula: wherein X2 represents an amino acid selected from Ser and d-Ser, X3 represents an amino acid selected from Gln and His, X7 represents an amino acid selected from Thr and Aib, X10 represents an amino acid residue selected from Tyr, Leu, Val, Ile, Phe, Phenylglycine, Thr, 2-Fluorophenylalanine, Cyclohexylglycine and tert-Leucine, X12 represents an amino acid selected from Lys, Arg and Cys(VS-DO3A), X13 represents an amino acid selected from Gln, Tyr and Cys(VS-DO3A), X14 represents an amino acid residue selected from Leu, Nle and Cys(VS-DO3A), X15 represents an amino acid selected from Glu and Asp, X16 represents an amino acid selected from Ser, Glu, Aib and Cys(VS-DO3A), X17 represents an amino acid selected from Arg, Gln, Lys, Ala and Cys(VS-DO3A), X18 represents an amino acid selected from Arg, Lys and Ala, X20 represents an amino acid selected from Gln, Glu, Aib, Lys and Cys(VS-DO3A), If X16 is Glu and X20 is Lys, the sidechains of X16 and X20 may form a cyclic ring via a lactam, X21 represents an amino acid residue selected from Asp and Glu, X28 represents an amino acid selected from Ala and β-Ala, X29 represents an amino acid residue selected from Gly and Thr, X32 represents an amino acid selected from Glu and Ser, X40 represents an amino acid selected from Cys(VS-DO3A), Cys(VS-NO2A), Cys(mal-DOTA), Cys(mal-NOTA), Cys(mal-NODAGA), Lys(DOTA), Lys(NOTA), Lys(PEG-DOTA) and Lys(VS-DO3A), or X40 may be absent if one of the amino acids X12, X13, X14, X16, X17 or X20 is Cys(VS-DO3A), wherein DOTA, NOTA, DO3A, NO2A or NODAGA may be unloaded or loaded with a metal ion selected from Gd 3+, Ga 3+, Cu 2+, (Al-F) 2+, Y 3+, Tc 3+, In 3+, Lu 3+ and Re 3+, R 1 represents OH or NH 2; and wherein the compound is a glucagon receptor agonist; or a metal complex or a salt or a solvate thereof. X2 represents an amino acid selected from Ser and d-Ser, X3 represents an amino acid selected from Gln and His, X7 represents an amino acid selected from Thr and Aib, X10 represents an amino acid residue selected from Tyr, Leu, Val, Ile, Phe, Phenylglycine, Thr, 2-Fluorophenylalanine, Cyclohexylglycine and tert-Leucine, X12 represents an amino acid selected from Lys, Arg and Cys(VS-DO3A), X13 represents an amino acid selected from Gln, Tyr and Cys(VS-DO3A), X14 represents an amino acid residue selected from Leu, Nle and Cys(VS-DO3A), X15 represents an amino acid selected from Glu and Asp, X16 represents an amino acid selected from Ser, Glu, Aib and Cys(VS-DO3A), X17 represents an amino acid selected from Arg, Gln, Lys, Ala and Cys(VS-DO3A), X18 represents an amino acid selected from Arg, Lys and Ala, X20 represents an amino acid selected from Gln, Glu, Aib, Lys and Cys(VS-DO3A), If X16 is Glu and X20 is Lys, the sidechains of X16 and X20 may form a cyclic ring via a lactam, X21 represents an amino acid residue selected from Asp and Glu, X28 represents an amino acid selected from Ala and β-Ala, X29 represents an amino acid residue selected from Gly and Thr, X32 represents an amino acid selected from Glu and Ser, X40 represents an amino acid selected from Cys(VS-DO3A), Cys(VS-NO2A), Cys(mal-DOTA), Cys(mal-NOTA), Cys(mal-NODAGA), Lys(DOTA), Lys(NOTA), Lys(PEG-DOTA) and Lys(VS-DO3A), or X40 may be absent if one of the amino acids X12, X13, X14, X16, X17 or X20 is Cys(VS-DO3A), wherein DOTA, NOTA, DO3A, NO2A or NODAGA may be unloaded or loaded with a metal ion selected from Gd 3+, Ga 3+, Cu 2+, (Al-F) 2+, Y 3+, Tc 3+, In 3+, Lu 3+ and Re 3+, R 1 represents OH or NH 2; and wherein the compound is a glucagon receptor agonist; or a metal complex or a salt or a solvate thereof.