Assistant in Xiao Yao San

Fú Líng 茯苓

Poria sclerotium · Poria (Poria cocos) · 30 g in the classical formula

Role in the formula

Fú líng partners bái zhú as the formula's second assistant. It leaches out dampness and strengthens the spleen from the other direction — where bái zhú dries and fortifies, fú líng drains and settles. Its quiet extra gift is to calm the spirit, a welcome action in a formula so often given for irritability and unease^[1].

Character

Sweet, bland, and neutral, entering the heart, spleen, and kidney channels. Among the most frequently prescribed substances in the entire pharmacopoeia, appearing wherever fluids need moving without harshness^[1].

In the pharmacy

Not a plant but a fungus: the sclerotium of Poria cocos, which grows on pine roots, cut into chalk-white cubes or slices. 30 g in the classical proportions.