薬 が 効く
薬効 Kanji
運よく薬が効くとき1時過ぎに寝れるけど、薬を飲まないと4時ぐらいまで眠れない。 If I'm lucky enough for the medicine to work I can get to sleep after 1am but if I don't take it then I can't sleep until about 4am.