薬が効く くすりがきく Meanings Expression, Godan verb to have medicine be effective Kanji 薬 drug. Read as くすり. 効 effect. Read as きく. Words containing 薬が効く 薬が効きすぎる (くすりがききすぎる) to work too well (of a punishment, reprimand, etc.) Jinuma: Japanese Dictionary · Word lists