Nowadays, different approaches are used to inhibit follicular development prevent ovulation, fertilization and embryo implantation for contraception. Hormonal contraceptives are commonly used to inhibit ovulation but are associated with many side effects. To identify novel non-hormonal compounds as contraceptives to prevent embryo implantation, we established a high-throughput human spheroid-endometrial epithelial cell co-culture model to screen the Library of Pharmacologically Active Compounds (LOPAC) for small molecules that affect the attachment of trophoblastic spheroids (blastocyst surrogate) onto endometrial epithelial cells (endometrium surrogate). A total of 174 out of 1280 LOPAC compounds significantly suppressed BeWo spheroid attachment onto endometrial Ishikawa cells. One of the top 20 active compounds (P11B5, Nemadipine-A) having the lowest cytotoxicity in Ishikawa cells was selected for further study. Nemadipine-A at 10 µM also significantly suppressed the attachment of BeWo spheroids onto endometrial epithelial RL95-2 cells (41.3 vs 52.3 %, p<0.01) and primary human endometrial epithelial cells (hEECs, 6.5 vs 17.1%, p<0.01) collected on LH+7/8 days. The suppressive effect on embryo implantation was also observed after transcervical injection of Nemadipine-A (100 µg/kg) or Misoprostol (250 µg/kg) but not Nemadipine-A at 10 µg/kg into mouse uterine cavity on 1.5 days post coitum (dpc) when compared with the controls. The expressions of endometrial receptivity markers integrin aV (ITGAV), mucin-1 (MUC1) but not b-catenin (CTNNB1) transcripts were statistically reduced on 2.5 dpc when compared with the untreated control. In sum, LOPAC screening identified Nemadipine-A as an inhibitor of spheroid attachment onto Ishikawa, RL95-2 cells and primary hEECs. The suppressive effect on mouse embryo implantation of Nemadipine-A may work through regulating endometrial receptivity molecules ITGAV and MUC1. Nemadipine-A can be a potential non-hormonal contraceptive drug inhibiting the implantation process. [Supported grants: the Sanming Project of Medicine in Shenzhen, China (SZSM201612083), Shenzhen Key Medical Discipline (SZXK2020089), General Research Fund, Research Grants Council, Hong Kong (17120720)]