A fusion protein comprising: a) an insulin receptor agonist having the general formula Z 1 -Z 2 -Z 3, wherein: i) Z 1 is an insulin B-chain analog, comprising the amino acid sequence: X 1 X 2 X 3 QHLCGSHLVEALX 4 LVCGERGFX 5 YX 6 X 7 X 8 X 9 wherein X 1 is F, Q or A; X 2 is V or G; X 3 is N, K, D, G, Q, A or E; X 4 is E, Y, Q, or H; X 5 is H or F; X 6 is G, T, S, H, V or is absent; X 7 is G, E, P, K, D, S, H or is absent; X 8 is G, E, K, P, Q, D, H or is absent; X 9 is G, T, S, E, K, A or is absent, provided that the insulin B-chain analog includes at least one modification from the amino acid sequence of the B-chain of a molecule of human insulin at X 4, X 5, X 6, X 7, X 8, or X 9 (SEQ ID NO:1); ii) Z 2 is a first peptide linker comprising 5 to 10 amino acids, wherein at least 5 of said amino acids are G residues; and iii) Z 3 is an insulin A-chain analog comprising the amino acid sequence: GIVEQCCTSX 1 CSLX 2 QLENYCX 3 X 4 wherein X 1 is T or I; X 2 is D, Y, Q or E; X 3 is G, N, S or A; and X 4 is any naturally occurring amino acid, or is absent, provided that if X 3 is N, then X 4 must be an amino acid other than G or N (SEQ ID NO:2); b) a second peptide linker having between 10 and 25 amino acids, wherein at least 50% of said amino acids are G residues; and c) a human IgG Fc region; wherein the C-terminal residue of the insulin receptor agonist is directly fused to the N-terminal residue of the second peptide linker, and the C-terminal residue of the second peptide linker is directly fused to the N-terminal residue of the human IgG Fc region. a) an insulin receptor agonist having the general formula Z 1 -Z 2 -Z 3, wherein: i) Z 1 is an insulin B-chain analog, comprising the amino acid sequence: X 1 X 2 X 3 QHLCGSHLVEALX 4 LVCGERGFX 5 YX 6 X 7 X 8 X 9 wherein X 1 is F, Q or A; X 2 is V or G; X 3 is N, K, D, G, Q, A or E; X 4 is E, Y, Q, or H; X 5 is H or F; X 6 is G, T, S, H, V or is absent; X 7 is G, E, P, K, D, S, H or is absent; X 8 is G, E, K, P, Q, D, H or is absent; X 9 is G, T, S, E, K, A or is absent, provided that the insulin B-chain analog includes at least one modification from the amino acid sequence of the B-chain of a molecule of human insulin at X 4, X 5, X 6, X 7, X 8, or X 9 (SEQ ID NO:1); ii) Z 2 is a first peptide linker comprising 5 to 10 amino acids, wherein at least 5 of said amino acids are G residues; and iii) Z 3 is an insulin A-chain analog comprising the amino acid sequence: GIVEQCCTSX 1 CSLX 2 QLENYCX 3 X 4 wherein X 1 is T or I; X 2 is D, Y, Q or E; X 3 is G, N, S or A; and X 4 is any naturally occurring amino acid, or is absent, provided that if X 3 is N, then X 4 must be an amino acid other than G or N (SEQ ID NO:2); i) Z 1 is an insulin B-chain analog, comprising the amino acid sequence: X 1 X 2 X 3 QHLCGSHLVEALX 4 LVCGERGFX 5 YX 6 X 7 X 8 X 9 wherein X 1 is F, Q or A; X 2 is V or G; X 3 is N, K, D, G, Q, A or E; X 4 is E, Y, Q, or H; X 5 is H or F; X 6 is G, T, S, H, V or is absent; X 7 is G, E, P, K, D, S, H or is absent; X 8 is G, E, K, P, Q, D, H or is absent; X 9 is G, T, S, E, K, A or is absent, provided that the insulin B-chain analog includes at least one modification from the amino acid sequence of the B-chain of a molecule of human insulin at X 4, X 5, X 6, X 7, X 8, or X 9 (SEQ ID NO:1); ii) Z 2 is a first peptide linker comprising 5 to 10 amino acids, wherein at least 5 of said amino acids are G residues; and iii) Z 3 is an insulin A-chain analog comprising the amino acid sequence: GIVEQCCTSX 1 CSLX 2 QLENYCX 3 X 4 wherein X 1 is T or I; X 2 is D, Y, Q or E; X 3 is G, N, S or A; and X 4 is any naturally occurring amino acid, or is absent, provided that if X 3 is N, then X 4 must be an amino acid other than G or N (SEQ ID NO:2); b) a second peptide linker having between 10 and 25 amino acids, wherein at least 50% of said amino acids are G residues; and c) a human IgG Fc region; wherein the C-terminal residue of the insulin receptor agonist is directly fused to the N-terminal residue of the second peptide linker, and the C-terminal residue of the second peptide linker is directly fused to the N-terminal residue of the human IgG Fc region.