Reproductive trigger hormone
Hypothalamic GnRH release gating
Also searched as Hypothalamic GnRH release gating.
You want it signaling: kisspeptin is the upstream gate, and when it closes the whole axis falls quiet regardless of how healthy the gonads are.It is a key integrator, not the sole switch — neurokinin B, dynorphin, leptin and estradiol feedback all act on the same neurons.
In depth
The hypothalamic neuropeptide that gates GnRH release — the switch sitting above the entire reproductive axis.
What drives it
Stress & cortisol reduces it.
10.1159/000553326 — Sex steroids exert negative feedback on kisspeptin neurons, and hypothalamic kisspeptin is suppressed by stress, obesity and metabolic disturbance — which is why low testosterone often presents with low-or-normal LH (a central problem) rather than the high LH of true testicular failure. doi 10.1159/000553326
Insulin sensitivity increases it.
Kisspeptin neurons are influenced by leptin and insulin (excitatory) and by ghrelin and adiponectin (inhibitory) — this is the junction where metabolic state reaches the reproductive axis, and it explains why obesity and metabolic disease suppress the axis centrally rather than at the testis (PMC8482951). stated as a regulatory influence on these neurons; the quantitative contribution relative to sex-steroid feedback is not established in the sources read here. PMC8482951
Restores fullness signal increases it.
Leptin, an anorexigenic adipokine secreted by white adipose tissue reflective of total body energy stores, is a permissive signal requisite for healthy GnRH neuronal function. doi 10.1152/physrev.00015.2024 · PMID 23550015 · PMC3786537
Testosterone reduces it.
gonadal sex steroid production... then has an inhibitory effect on kisspeptin neurons. doi 10.1152/physrev.00015.2024 · PMID 23550015 · PMC3786537
Estrogen balance reduces it.
estrogen acting through ERalpha induces histone acetylation of the Kiss1 promoter; sex steroid feedback on kisspeptin neurons is negative in the arcuate population. doi 10.1152/physrev.00015.2024 · PMID 23550015 · PMC3786537
Prolactin reduces it.
Prolactin acts on prolactin receptors on KNDy neurons to suppress kisspeptin expression. PMID 23006326
What it drives
It increases Reproductive axis.
Human genetics is decisive: inactivating mutations of the kisspeptin receptor (GPR54/KISS1R) in humans cause failure to PROGRESS through puberty and adult infertility — hypogonadotropic hypogonadism with capable gonads that are never signaled. Loss of function, pharmacological: the selective antagonist peptide 234 inhibited the post-castration LH rise in mice, blunted the LH response in rats, and suppressed LH pulse frequency and amplitude in ewes and GnRH pulses in monkeys. Gain of function, in humans: 12-hour intravenous Kp-10 in women with cabergoline-resistant hyperprolactinaemic amenorrhoea significantly raised LH and FSH, increased LH pulses, and raised estradiol, testosterone and inhibin B (PMC5686678). Hierarchy: kisspeptin neurons in the arcuate and AVPV nuclei release kisspeptin → KISS1R on GnRH neurons → GnRH into the portal circulation → LH and FSH from the anterior pituitary → gonad. Why the gate must exist at all: GnRH neurons lack estrogen receptor alpha and progesterone receptors, so sex-steroid feedback cannot act on them directly — it is relayed through kisspeptin neurons. kisspeptin is a key integrator, not the sole switch — neurokinin B, dynorphin, leptin and estradiol feedback all converge on the same cells; and it is not a simple booster, since its effect depends on the state of the individual's axis. doi 10.3389/fendo.2022.925206 · PMC5686678
It increases The Two-Faced Peptide.
Kisspeptin neurons of the arcuate nucleus co-express neurokinin B and dynorphin — they are called KNDy neurons for those three peptides. KNDy cells mediate both the positive and negative feedback of estrogen onto GnRH secretion, and the arcuate is the site of the GnRH pulse generator. Dynorphin is best known as a stress and dysphoria signal; here the same peptide has a second, reproductive job in the same cells. doi 10.3389/fendo.2022.925206 · PMC2789414
It increases Reproductive trigger.
PMC4508256 — Kisspeptin neurons drive GnRH release - GnRH neurons themselves lack steroid receptors, which is why the feedback runs through kisspeptin. PMC4508256
It increases Temperature stability in menopause.
PMC12051537 — Drawn from reviews of neighboring outcomes rather than from studies of this outcome itself, which is weaker evidence, and the map marks it so. Verbatim: “These data suggest that arcuate KNDy neurons relay estrogen signals to preoptic structures regulating heat-dissipation effectors, supporting the hypothesis that KNDy neurons participate in the generation of flushes”. doi 10.1016/j.yfrne.2013.07.003 · PMID 23872331 · PMC12051537
Blends that modulate it
Each blend page names this pathway and carries the study behind its claim.
See it on the map
Open the causal map to follow this pathway upstream and downstream, arrow by arrow, each with its study.