Yixiao San: Powder that Activates Blood, Attacks Toxicity, Reduces Swelling, and Dissolves Nodules

In Shengji Zonglu (Comprehensive Records of Divine Relief) there is a formula called "Yixiao San" ("Extraordinary-Effect Powder") for treating luoli jiehe (scrofulous nodules—lymph-node tuberculosis, tumors, and similar conditions). The composition is very simple: 49 specimens of the blister beetle Lytta, and 1 liang (30 g) of dragon's-blood resin. Preparation: calcine the two ingredients until charred but retain their essence, then lay them on the earth to dispel the fire toxin; grind to a fine powder. Take 5 fen (1.5 g) each time, mixed with rice water, gradually increasing to 1 qian, three times daily.

This formula activates blood and attacks toxicity. It is indicated for luoli jiehe that has long failed to heal. In TCM, long-standing luoli jiehe may be lymph-node tuberculosis or a malignant tumor. The formula uses only two herbs, and both have anti-tumor action.

The yuanging in this formula is the whole insect Lytta caragana Pallas (family Meloidae), widely distributed throughout China. Yuanging is also known as Qingniangzi or Qingniangchong; ancient Chinese physicians used it medicinally from an early period. Medical texts of successive dynasties record that yuanging attacks toxicity, breaks stasis, and drives out water, and it was used for scrofula, rabid-dog bites, menstrual amenorrhea due to blood stasis, and edema with scant urination. From these records, the ancients used yuanging to treat lymph-node tuberculosis, lymphoma, ascites, rabies, and female amenorrhea.

Yuanging is highly toxic, and taking it internally carries great risk. It belongs to the class of herbs that "attack poison with poison," and is often used together with another such insect medicament, the blister beetle Mylabris (Banmao). Under China's current regulations on toxic drugs, the great majority of pharmacies do not sell yuanging. Liu Juanzi Guiyi Fang, China's earliest surgical work, already records the two used together to treat swelling-ulcer diseases: "For fistula and swelling diseases: forty Mylabris (head, feet, and wings removed, processed), 4 fen of cassia bark, ten yuanging (feet and wings removed, processed), thirty Ge Shang Tingzhang [Epicauta gorhami, processed]. Pound the four ingredients and sift; take half a spoonful with wine, once daily. Avoid raw scallion." This formula, like Yixiao San, does have some effect, but both are also extremely prone to causing medical accidents, so they must be used with the greatest caution.

Among the folk, a few people still use yuanging and Mylabris to treat disease, but there are occasional reports of fatal poisoning. Patients using such formulas must take special care not to use an excessive dosage or a prolonged course, in order to avoid fatal poisoning.