Centchroman is :

Centchroman/ Ormeloxifene Nonsteroidal estrogen antagonist : SERM (Selective estrogen receptor modulator) Developed at CDRI, Lucknow. Tablets of 30 mg to be taken twice a week for 3 months and then once a week for contraception . Has a weak Estrogenic and potent antiestrogenic effect--acting mostly on the endometrial target organs to suppress proliferation of the endometrium, thereby interfering with nidation of the embryo; Causes asynchrony between the Ovulation and the endometrial development Other uses: Breast cancer, benign breast diseases, abnormal uterine bleeding