The invention is related to fast acting insulin analogues which can form soluble mix-tures (pre-mixed or self-mixed) with long acting insulin analogues. The fast action is achieved through monomerizing substitutions/deletions in the C-terminus of the B-chain of human insulin and the mixability with long acting insulin analogues is achieved through a substitution of the Zn-binding His in position B10 of human insulin with a Gln amino acid residue. In one embodiment the invention is related to fast acting insulin analogues in which at least one of the natural amino acid residues in position B22-B30 in the human B-chain has been substituted with another amino acid residue having the effect of promoting formation of the monomeric form of insulin, the His amino acid residue in position 10 in the B-chain is substituted with a Gln and wherein further one or more of the amino acid residues in position B22-B30 optionally have been deleted.