Wulingzhi, the dried feces of flying squirrels used as medicine, is a traditional Chinese herbal medicine known for promoting blood circulation and resolving blood stasis.

Wulingzhi is a traditional animal-derived Chinese herbal medicine obtained from the dried feces of the complex-toothed flying squirrel (Trogopterus xanthipes) and related species in the family Pteromyidae. It is mainly produced in the mountainous areas of North China and Southwest China, and is a relatively rare variety among Chinese herbal medicines in that it uses animal excrement as its medicinal material. When the ancients named it, they generally believed it resembled congealed fat and embodied the spiritual essence of the five elements, hence the name Wulingzhi.

According to appearance, Wulingzhi is usually divided into two types: pieces that stick together into irregular lumps, called Lingzhi Kuai, also known as Tanglingzhi; and loose granular pieces, called Lingzhi Mi, also known as Sanlingzhi. The two have similar medicinal properties, and traditional experience holds that those that are blackish-brown, glossy and free of impurities are the best.

In traditional Chinese medicine, Wulingzhi is sweet in flavor and warm in nature, and is good at promoting blood circulation, resolving blood stasis and clearing the blood vessels. It is often used for stabbing pain in the epigastrium and abdomen, dysmenorrhea and postpartum abdominal pain caused by blood stasis obstruction, and it also has the effect of resolving stasis and stopping bleeding. The classic formula Shixiao San uses Wulingzhi combined with Puhuang (cattail pollen), and is a commonly used combination for treating blood stasis pain.

When using it, note that pregnant women should use it with caution, and according to the traditional statements on incompatibility in Chinese herbal formulas, Wulingzhi should not be used together with ginseng. Because wild flying squirrels are limited by ecological resources, the current source of the medicinal material relies more on artificial breeding, and after collection it must undergo preliminary processing such as sun-drying and removal of impurities before it can be used as medicine.