Method for producing a fibroin powder from silk products or filaments without sericin and dyes having the following phases: a) introduction of products or filaments into a very tightly-woven sealed bag with high filtering capacity to allow the treatment liquid but not the silk fibrils to exit; b) introduction of the bag into a tank with fresh and hot water with a mixer, in which soda is added to the water for a time of some hours; c) a rinsing phase of which the last is made with acetic acid in such a way as to make the fiber acceptable to the cutis as originally; d) phase of centrifugation and drying tumbler; e) tumbling phase, first opening the bags to throw away the material dried in the tumblers by pulverizing the fiber with a homogenous fragmentation in such a way as to keep the fibrils whole.