Biodegradable additive concentrate with pour point according to standard ASTM D 97 below −5° C., improving the lubricity of water-based muds, comprising at least one compound selected from the group consisting of: the diglycerol mono- and diesters, the acids and the ester derivatives of monocarboxylic fatty acids comprising from 16 to 22 carbon atoms per chain, the acids and the ester derivatives of resin acids, the monoesters of polyol comprising more than 4 hydroxylated groups and of carboxylic fatty acids comprising from 6 to 12 carbon atoms, saturated and unsaturated by at least one unsaturation, and the mono- and polyalkoxylated esters of saturated and unsaturated dicarboxylic acids comprising from 6 to 12 carbon atoms. The use of this concentrate in a water-based mud and the water-based mud containing said concentrate that can be used for drilling.