4,4-Diarylbutadienes of the formula I, where the diene system has the Z,Z; Z,E; E,Z or E,E configuration or a mixture thereof, and where the variables independently of one another have the following meanings: R1 and R2 are hydrogen, C1-C20-alkyl, C2-C10-alkenyl, C3-C10-cycloalkyl, C3-C10-cycloalkenyl, C1-C12-alkoxy, C1-C20-alkoxycarbonyl, C1-C12-alkylamino, C1-C12-dialkylamino, aryl, hetaryl, unsubstituted or substituted, substituents which confer solubility in water and are selected from the group consisting of carboxylate, sulfonate, or ammonium residues; R3 is COOR5, CONR5R6; R4 is COOR6, CONR5R6; R5 and R6 are hydrogen, C1-C20-alkyl, C2-C10-alkenyl, C3-C10-cycloalkyl, C7-C10-bicycloalkyl, C3-C10-cycloalkenyl, C7-C10-bicycloalkenyl, aryl, hetaryl, unsubstituted or substituted; n is 1 to 3; and R3 and R4 are not COOCH3 when R1 and R2 are hydrogen, are used as photostable UV filters in cosmetic and pharmaceutical preparations to protect the human skin or human hair from the sun's rays, alone or together with compounds which absorb in the UV region and are known per se for cosmetic and pharmaceutical preparations.