PROBLEM TO BE SOLVED: To provide a preparation that promotes the formation of an elastic fiber.SOLUTION: The present invention provides an elastic fiber formation promoter and an elastic fiber-associated factor production promoter that contain at least one selected from the group consisting of cyanocobalamine, and aspartic acid and a salt thereof.SELECTED DRAWING: NoneCOPYRIGHT: (C)2020,JPO&INPIT【課題】弾性線維の形成を促進する製剤を提供すること。【解決手段】シアノコバラミン、並びにアスパラギン酸及びその塩からなる群より選択される少なくとも1種を含有する、弾性線維形成促進剤及び弾性線維関連因子産生促進剤。【選択図】なし