The invention relates to a water-soluble polymer product in particle form, comprising amphoteric polyacrylamide, which is obtained by gel polymerisation of acrylamide together with anionic and cationic monomers. The amphoteric polyacrylamide has a mass average molecular weight MW of 1 500 000-6 000 000 g/mol, and a total ionicity of 4-15 mol-%, whereby the polymer product has a polymer content of at least 60 weight-%. The invention relates also to uses of the polymer product in paper and board making.