TCM herbal formula Si-Wu-Tang (Hemo.SWT) which is widely used for women's health. The human breast cancer cells treated with 2.56 mg/ml of SWT showed dramatic gene expression changes. Pathway analysis using differentially expressed genes related to the treatment effect identified that expression of genes in the Nrf2 cytoprotective pathway was most significantly affected by SWT. Five main Nrf2-regulated genes are upreguated by SWT in a dose-dependent manner. Consistently, treatment with SWT and its four herbal ingredients resulted in an increased antioxidant response element (ARE)-luciferase reporter activity in breast and kidney cells. Studies validate SWT's widely claimed use for women's diseases and indicating a phytoestrogenic effect.