Kisspeptin-54
Limited human dataAlso known as: Metastin · KP-54
A naturally occurring neuropeptide that is the master regulator of the reproductive hormone axis, now in early clinical development as a fertility and psychosexual therapeutic. Distinct from the melanocortin-based sexual-health peptides—it works directly on the reproductive hormone cascade.
Mechanism (plain language)
Stimulates hypothalamic GnRH neurons, driving downstream release of LH, FSH, and (in men) testosterone. This upstream mechanism differs fundamentally from melanocortin agonists like bremelanotide or Melanotan II.
What research suggests
Controlled human infusion and injection studies in both men and women reliably show dose-dependent increases in LH and FSH, with the female response varying by menstrual-cycle phase. It's being explored for fertility treatment (oocyte maturation triggers) and, separately, was tested for effects on anxiety with no significant effect found.
Uncertainties & risks
Most human work is short-term physiology/pharmacology studies (infusions, single doses), not outcome trials on fertility or libido; no approved kisspeptin product exists yet. Animal studies on anxiety-related effects have been inconsistent, and a rigorous human RCT found no effect on anxiety measures.
Primary sources
Secondary citations for verification. Prefer the STACKD summary above for context before opening these.
- Kisspeptin-54 stimulates gonadotropin release most potently during the preovulatory phase of the menstrual cycle in women
2007 · human
Dose-dependent LH increases in women, with the strongest response in the preovulatory phase.
- Kisspeptin-54 stimulates the hypothalamic-pituitary gonadal axis in human males
2005 · human
IV infusion significantly increased LH, FSH, and testosterone in healthy men.