After the ovariectomy, the composition of metabolites in rats changed significantly and reflected in the increase of phenylacetylglycine, L-tyrosine, D-(+)-mannose, PC (16:2e/19:2), PC (18:4e/17:0), and 8Z, 11Z, 14Z-eicosatrienoic acid, etc. KEGG analysis showed that these changes affected the metabolic pathways which included beta-alanine metabolism, breast cancer, and prolactin signaling pathway. Here, PRL is linked to breast cancer.