Objective: To explore the effect of Dahuang Zhechong capsule (DZC) for treating endometriosis and the influence to prostaglandin (PG). Method: Sixty-seven cases of patients with endometriosis were randomly divided into control group and experimental group

while control group was received mifepristone (12.5 mg daily)

and experimental group received DZ

5 tablets bid. The treatment was lasted for 12 weeks. Score of visual analogue scale(VAS) and the score of B&B multidimensional scale were investigated

and the level of plasma PGs were determined. Result: VAS score in the experimental group was lower than that in the control group (P<0.05). B&B multidimensional scale score in the experimental group was lower than that in the control group (P<0.01). Level of prostaglandin F2a (PGF2a)

prostaglandin E2(PGE2) and thromboxane B2 (TXB2) of experimental group was lower than those of control group (P<0.05). But level of 6-keto-PGF1a of experimental group was higher than that of control group (P<0.01). Conclusion: For treating patients with endometriosis

DZC can improve symptom and signs. The effect of alleviating dysmenorrhea is likely related to regulation of levels of PGs.