Metabolites as Signaling Molecules: Indispensable Roles in the Regulation of Embryo Implantation

The process of embryo implantation is complex yet highly coordinated, involving differentiation of multiple cell types and dynamic mechanistic or compensatory shifts in metabolic patterns. Metabolic regulation plays a critical role in embryo implantation by modulating embryo competence and endometrial receptivity. Accordingly, metabolites function not only as sources of energy but also as signaling molecules that orchestrate communication between the endometrium and blastocyst. Here, we review the regulatory roles of key metabolites, including glucose, lipids, amino acids, and their derivatives in various reproductive processes, such as blastocyst formation and activation, establishment of uterine receptivity, and embryo implantation. Interpretation of metabolic signaling may help to elucidate the intricate process of embryo implantation and provide new insights into potential clinical interventions and improvements in assisted reproductive technology.