Kisspeptin

Kisspeptin is a neuropeptide encoded by the KISS1 gene and is recognised in the literature as the master upstream regulator of the reproductive endocrine axis. The commonly studied research form is kisspeptin-10, the shortest C-terminal fragment that retains full receptor activity. Its discovery reshaped the understanding of how the brain initiates and sustains reproductive function.

Mechanism

Kisspeptin binds KISS1R (GPR54), a G-protein coupled receptor expressed on gonadotropin-releasing hormone neurons in the hypothalamus. Activation of these neurons triggers pulsatile GnRH release, which drives the pituitary secretion of luteinising hormone and follicle-stimulating hormone, and in turn the downstream production of endogenous sex steroids. Because it acts at the very top of the hypothalamic–pituitary–gonadal cascade, kisspeptin stimulates the body's own signalling architecture rather than substituting for it — the resulting hormone release remains physiologically pulsatile and subject to native feedback control.

What the research shows

• Robust, dose-dependent stimulation of LH and FSH release in human and animal studies
• Restoration of gonadotropin pulsatility in models of hypothalamic suppression
• Preservation of natural feedback regulation, distinguishing it from direct hormone administration
• Activation of limbic and paralimbic brain regions associated with sexual and emotional processing in neuroimaging studies
• Established role as a diagnostic probe of hypothalamic–pituitary function in clinical research

Kisspeptin is central to contemporary research on reproductive endocrinology, puberty onset, fertility and the neurobiology of attraction.