Abstract: Anticoagulant products are constituted by polymers (homopolymers or copolymers) including in their chain substitutable groups on which are fixed statistically, groups X and/or Y and/or V, where X denotes the group --SO.sub.3 R.sub.1 or --R.sub.3 --SO.sub.3 R.sub.1, R.sub.1 being a hydrogen atom or a physiologically compatible metal, R.sub.3 being a --CH.sub.2 --CO--NH--R.sub.4 group in which R.sub.4 represensts an alkyl aryl or alkylaryl radical, which may or may not be substituted, or substituted or unsubstituted --CH.sub.2 --; Y denotes the group --SO.sub.2 --R.sub.2 or --R.sub.3 --SO.sub.2 --R.sub.2, R.sub.2 being the residue of an amino acid connected to the --SO.sub.2 bridge through its amine function and V denotes the group --CH.sub.2 --CO--NH--CHR--COOH, R being the side chain of an amino acid it being understood that: (a) if X is --SO.sub.3 R.sub.1 it is necessarily accompanied by Y and/or by V, and (b) V is always accompanied by X and/by Y.