An agent for preventing or ameliorating overactive bladder, which is useful for preventing or ameliorating overactive bladder and alleviating various symptoms associated therewith, is provided. An agent for preventing or ameliorating overactive bladder comprising as an active ingredient at least one selected from 3,3'-di-O-methylrosmarinic acid or a metabolic precursor thereof, or a salt or solvate thereof. . [Selection diagram] None【課題】過活動膀胱の予防又は改善、及びそれに伴う諸症状の緩和に有用な、過活動膀胱の予防又は改善剤を提供する。【解決手段】３，３’－ジ－Ｏ－メチルロズマリン酸若しくはその代謝前駆体、又はそれらの塩若しくは溶媒和物から選択される１種以上を有効成分とする過活動膀胱の予防又は改善剤。【選択図】なし
