The invention relates to a composition, in the form of an aqueous solution, comprising insulin in hexameric form, at least one substituted anionic compound having a non-saccharide structure and at least one polyanionic compound other than said substituted anionic compound, characterized in that the substituted anionic compound corresponds to the following formula (I) in which: R is a saturated or unsaturated hydrocarbon-based radical comprising 1 or 2 carbon atoms, optionally comprising one or more function(s) chosen from alcohol, ether and carboxylic acid functions, AA is a radical derived from a natural or synthetic aromatic amino acid comprising a phenyl group or an indole group, which is substituted or unsubstituted, said AA radical having at least one free carboxylic acid function, E is a linear or branched, saturated or unsaturated hydrocarbon-based radical, which is at least divalent, comprising from 1 to 6 carbon atoms, optionally comprising one or more function(s) chosen from alcohol and carboxylic acid functions, F, F' and F" being, independently of one another, a function chosen from amide, carbamate or urea functions, F and F" being functions resulting from a reaction involving the amino of the aromatic amino acid, precursor of the AA radical, and a reactive function of the precursors R' of R or E' of E, F' being a function involving a reactive function of the precursor R' of R and a reactive function of the precursor E' of E, p being an integer between 1 and 3, m being an integer between 0 and 4, n being an integer between 0 and 4, m + n being an integer between 1 and 4； wherein said compound comprises at least 2 carboxylic acid functions in the form of a salt an alkali metal chosen from Na+ et K+.L'invention concerne une composition, sous forme de solution aqueuse, comprenant de l'insuline sous forme hexamérique, au moins un composé anionique substitué de structure non saccharidique et au moins un composé polyanionique différent dudit composé anionique
