The review explains that the brain cells that make kisspeptin, a hormone that triggers reproductive signals, are tightly controlled by the body's energy status. When you have enough fuel (calories, fat stores), kisspeptin production goes up, helping fertility; when energy is low, production drops. The article also notes that kisspeptin can feed back to affect how the brain regulates appetite and metabolism, creating a two‑way link between metabolism and reproduction.

Hypothalamic kisspeptin neurons serve as the nodal regulatory centre of reproductive function. These neurons are subjected to a plethora of regulatory factors that ultimately affect the release of kisspeptin, which modulates gonadotropin-releasing hormone (GnRH) release from GnRH neurons to control the reproductive axis. The presence of sufficient energy reserves is critical to achieve successful reproduction. Consequently, metabolic factors impose a very tight control over kisspeptin synthesis and release. This Review offers a synoptic overview of the different steps in which kisspeptin neurons are subjected to metabolic regulation, from early developmental stages to adulthood. We cover an ample array of known mechanisms that underlie the metabolic regulation of KISS1 expression and kisspeptin release. Furthermore, the novel role of kisspeptin neurons as active players within the neuronal circuits that govern energy balance is discussed, offering evidence of a bidirectional role of these neurons as a nexus between metabolism and reproduction.