味甘微温.入手足太阴经.功专益气.得当归、活血.得白术、补气.得防风其功益大.得滑石、白糖煎服.治洞泄完谷不化神效.合人参、甘草、生姜为保元汤.治痘虚不起.或加芎 、官桂糯米助之.生凉炙温.生用或酒炒达表.蜜炙补中.盐水炒补肾.茯苓为使.恶龟甲、白藓皮.畏防风.气旺者禁用.阴虚者宜少用.