Animals treated with n-hexane fraction of V. negundo showed very low superoxide anion radical level resulting in “nonreceptive endometrium,” which failed to accept blastocyst and finally led to implantation failure. Failure in blastocyst implantation may be attributed to antiestrogenic and anti-inflammatory properties of n-hexane fraction of V. negundo. Antiestrogenic property of n-hexane fraction of V. negundo was confirmed by decrease in uterine weight upon administration of the extract. Additionally, the n-hexane fraction of V. negundo is rich in triterpenoids like lupeol and β-sitosterol, which are good anti-inflammatory agents [29]. Presence of these agents may downregulate the various mediators such as cyclooxygenase, various cytokines, nitric oxide, and superoxide anion radical. However, as n-hexane fraction shows very good antiestrogenic activity, it may also downregulate these mediators. Hence, n-hexane fraction of V. negundo modulates two different yet interrelated pathways, inflammatory cascade and estrogen signaling, resulting in alteration in the physiology of the endometrium making it “nonreceptive” which further results in the failure of blastocyst implantation.