Kisspeptin-10

Kisspeptin-10 (KP-10), also called metastin 45-54, is the smallest fragment of kisspeptin that still fully activates the kisspeptin receptor, KISS1R ¹. The KISS1 gene got its name from its metastasis-suppressing 'metastin' products, but kisspeptin is better known today as the brain's main 'on' signal for reproductive maturation ¹.

Kisspeptin neurons sit upstream of gonadotropin-releasing hormone (GnRH) neurons. When KISS1R is activated, GnRH release tells the pituitary to secrete luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which then drive testosterone, estradiol, ovulation, and sperm production ². People born with loss-of-function KISS1R mutations fail to enter puberty, which is how kisspeptin was identified as a gatekeeper of reproduction ⁴⁸.

Human kisspeptin-10 research has focused on short, controlled protocols that stimulate this pathway: acute and intermittent subcutaneous infusions in healthy men, continuous intravenous probes, and case reports in women with prolactinoma-related amenorrhea ². Preclinical studies also cover glucose metabolism, bone density, neuroprotection, and cardiovascular effects ¹⁴. Cancer data are split, with some models showing metastasis suppression and others showing pro-invasive signaling ²¹.

• Fertility and reproductive hormone restoration: human RCTs and case reports; moderate confidence ².
• Diagnostic testing of the hypothalamic-pituitary axis: small human studies; moderate confidence ⁴⁹.
• PCOS and ovulation induction: mostly kisspeptin-54 data and animal models; low to moderate confidence ⁵.
• Metabolic, bone, and brain effects: preclinical only ¹⁴.

Kisspeptin-10 binds and activates KISS1R (GPR54), a G protein-coupled receptor on gonadotropin-releasing hormone (GnRH) neurons. Receptor activation opens intracellular calcium signaling and triggers ERK/MAPK pathways ¹. This excites GnRH neurons, leading to pituitary LH and FSH release and downstream gonadal steroid production ².

Two populations of kisspeptin neurons map onto two release modes. Arcuate-nucleus neurons, which also carry neurokinin B and dynorphin (called KNDy neurons), generate the pulsatile mode. Neurons in the AVPV/RP3V region drive the pre-ovulatory surge ⁵⁵. Exogenous kisspeptin-10 reproduces the downstream cascade in humans, raising LH, FSH, and testosterone dose-dependently ².

• Direct gonadal signaling: the testis and ovary express the kisspeptin system; deleting Gpr54 from oocytes causes premature ovulatory failure ⁴³. Kisspeptin-10 also increases granulosa-cell proliferation and steroid secretion in vitro ⁵⁸.
• Placental function: kisspeptin-10 is a physiological inhibitor of trophoblast invasion, helping control implantation depth ⁵⁹. Placental kisspeptin is reduced in early fetal growth restriction and pre-eclampsia ⁴⁰.
• Metabolic signaling: kisspeptin potentiates glucose-stimulated insulin secretion through a Gβγ-dependent redox pathway distinct from GLP-1 ¹⁶.
• Bone: Gpr54 activation on osteoclasts suppresses bone resorption via Dusp18-mediated Src regulation ³⁴.
• Vascular effects: kisspeptin-10 causes acute vasoconstriction and, with prolonged infusion, accelerates atherosclerotic plaque progression in mice ²⁴.
• Neuroinflammation: in microglia, it suppresses the NLRP3-caspase-1 pyroptosis pathway and promotes clearance of protein aggregates ²⁹.
• Other pituitary outputs: kisspeptin stimulates prolactin release ⁶⁰, and an intravenous bolus raised oxytocin in humans ⁵⁰.

The peptide is short-lived: the reported mouse plasma half-life is about 4 minutes, compared with about 32 minutes for kisspeptin-54 ⁹. Kisspeptin-54 crosses the blood-brain barrier more effectively than kisspeptin-10 after peripheral injection, which is likely why sustained LH release differs between isoforms ⁹. Study designs therefore favor repeated, continuous, or pulsatile delivery ².

Human reproductive hormone effects

• In healthy men, 8-hour subcutaneous infusions of 1.25-10 nmol/kg/h produced dose-dependent increases in LH, FSH, and testosterone versus placebo ².
• An intermittent schedule (150 nmol/h for 8 hours on, 16 hours off) maintained LH elevation through 12 days, while 5 days of continuous infusion lost the gonadotropin response ².
• A 24-hour intravenous infusion at 12.5 mcg/kg/h drove LH 5-8 times above baseline, peaking at 12-20 hours, before declining 13-47% as partial tachyphylaxis developed ³.
• Two women with cabergoline-resistant prolactinoma amenorrhea regained LH pulses and rises in FSH, estradiol, testosterone, and inhibin B during 12-hour IV infusions ⁴.
• A 0.24 nmol/kg IV bolus raised oxytocin by 18.8% at 10 minutes in healthy adults, with a larger response in men ⁵⁰.

Preclinical fertility outcomes

• In rabbits, 250 mcg IV induced ovulation in 87.5% of animals, similar to GnRH ⁴⁶.
• In sows, 0.5 mg IM at fixed-time artificial insemination matched GnRH on pregnancy and piglet outcomes ⁴⁵.
• In cattle, kisspeptin-10 raised LH but did not reliably trigger luteal-phase ovulation at the doses tested ⁵².
• Hourly pulsatile dosing advanced first menstruation by about 3.3 months in prepubertal monkeys ⁴⁷.

Other documented preclinical effects

• In high-fat-fed female mice, twice-daily kisspeptin-10 normalized body weight, glucose, and energy intake ¹⁴, and in diabetic monkeys it prevented insulin-induced hypoglycemic shock ¹⁵.
• In ovariectomized rodents, kisspeptin-10 prevented bone loss when started immediately ³³.
• In stroke and neuroinflammation models, it reduced infarct size and supported blood-brain barrier integrity ²⁸.
• Cancer outcomes differ by model: some studies show inhibition of tumor angiogenesis and growth ¹⁷, while others show kisspeptin-10 promotes invasion in certain breast cancer lines via EGFR transactivation ²².

Human kisspeptin-10 studies have used intravenous or subcutaneous infusion delivery rather than repeated standalone injections ². The best-characterized repeated-administration protocol is an intermittent SC infusion: 150 nmol/h (roughly 195 mcg/h) for 8 hours per day, with 16 hours off, continued for 12 days ².

This schedule kept LH elevated through day 12 with the receptor still responsive to a follow-up 1 nmol/kg bolus. By contrast, continuous SC infusion for 5 days returned gonadotropins to vehicle levels, and a 24-hour IV infusion showed partial tachyphylaxis by the end ². Pulsatility is the key variable, not total dose.

Other published schedules include:

• Acute dose-response: 1.25-10 nmol/kg/h SC infusion for 8 hours ².
• Continuous IV probe: 12.5 mcg/kg/h for 24 hours ³.
• Amenorrhea therapy: 1.5 mcg/kg/h IV for 12 hours, repeated on 2 consecutive days ⁴.
• Diagnostic bolus: 0.24 nmol/kg IV, used to test oxytocin and axis responsiveness ⁵⁰.

Because no human trial has validated simple SC bolus regimens, community protocols have extrapolated doses of 100-500 mcg one to three times daily, often with intermittent days. Those doses fall far below a single 8-hour infusion session and have no published human efficacy evidence. A visual timeline on this page shows the key protocol steps.

Kisspeptin-10 is supplied as a lyophilized powder. For multi-dose research vials, bacteriostatic water is the standard diluent; sterile water is acceptable for single use. Inject the diluent slowly down the vial wall and swirl gently. Shaking or vortexing can foam and damage the peptide.

Do not use serum or plasma as a diluent. Kisspeptin-10 undergoes rapid N-terminal degradation in plasma ¹¹, and matrix metalloproteinases cleave it at the Gly-Leu bond ¹³. A degraded sample can also show oxidation of its tryptophan residue ⁸.

For storage, keep lyophilized powder at -20°C for long-term use, or at 2-8°C for short-term use, protected from light and moisture. After reconstitution, refrigerate at 2-8°C. With bacteriostatic water, research handling typically uses the solution within 14-30 days; with sterile water, within 24 hours. Avoid repeated freeze-thaw cycles. This page's interactive dilution calculator handles the volume arithmetic for specific vial sizes and doses.

Formal interaction studies do not exist for kisspeptin-10, so most guidance comes from mechanism, small human studies, and animal work.

• GnRH agonists or antagonists: these share the same downstream pathway. Chronic kisspeptin analogs can suppress the axis instead of stimulating it ⁶⁴, so concurrent use is redundant and may accelerate tachyphylaxis.
• Insulin: in diabetic monkeys, kisspeptin-10 given before or with insulin prevented hypoglycemic shock ¹⁵, and in isolated islets it potentiates glucose-stimulated insulin secretion ¹⁶. Glucose monitoring is a sensible precaution in insulin-treated models.
• GLP-1 receptor agonists: kisspeptin and GLP-1 act on islet cells through separate pathways, and kisspeptin increased GLP-1-positive gut cells in obese mice ¹⁴. Appetite and insulin effects may overlap, but acute kisspeptin can transiently raise glucose ¹¹.
• Dopamine agonists: kisspeptin-10 restored reproductive hormone output in two women whose amenorrhea had resisted cabergoline ⁴, suggesting it acts downstream of prolactin suppression.
• NK3R antagonists such as fezolinetant: one study found an NK3R antagonist limited kisspeptin-10-induced LH secretion in women ⁷².
• Sex steroids: estradiol priming potentiated the LH response to kisspeptin-10 in cows ⁷³, so estrogen-containing treatments could shift the response.
• Supplements: adequate zinc supports kisspeptin expression ⁸⁰, while phytoestrogens like formononetin and stigmasterol can downregulate kisspeptin/GnRH signaling in animals ⁷⁸.
• Condition cautions: PCOS has elevated endogenous kisspeptin and unpredictable responses ⁵, kidney failure shows kisspeptin excess with blunted gonadal function ³⁷, and pregnancy should be avoided ⁴⁰.

Kisspeptin-10's main tolerance issue is tachyphylaxis: the receptor stops responding when constantly stimulated. During a 24-hour IV infusion, LH fell 13-47% from its peak before the infusion ended ³. Five days of continuous SC infusion returned gonadotropins to placebo levels ².

Intermittent delivery avoids that. The 8-hours-on, 16-hours-off schedule sustained LH for 12 days with a still-responsive receptor ². More potent continuous kisspeptin analogs can push the system in the opposite direction in animals, depleting GnRH and lowering testosterone to castrate levels ⁶⁴. Long-term high endogenous kisspeptin in dialysis patients is also associated with blunted gonadal responses ³⁷.

Community research protocols therefore use brief pulses and scheduled breaks rather than continuous exposure. Common structures include 5 days on / 2 days off, or 4-8 weeks on followed by 2-4 weeks off, with some protocols using only a few 100-250 mcg bolus days per week. No human trial has validated a specific cycle length beyond the 12-day intermittent RCT ².

Preclinical cautions support keeping exposures intermittent. Daily IV dosing in dogs produced a smaller LH response by day 14 than day 1 ⁷, and twice-daily dosing in prepubertal rats caused dose-dependent Leydig cell degeneration ⁴¹.

• hCG or HMG: concept is complementary: kisspeptin-10 drives endogenous LH/FSH release from the pituitary, while hCG acts directly on ovarian or testicular LH receptors ². No formal interaction study exists, but this combination is discussed in fertility research.
• GLP-1 receptor agonists: separate insulin-stimulating pathways could be additive, but acute glucose effects can differ ¹¹.
• PT-141: separate receptor systems. Kisspeptin-10 restores sexual approach behavior in stressed male rats ³², and PT-141 works through melanocortin receptors, so additive sexual-function effects are plausible but unstudied in humans.
• Oxytocin: kisspeptin-10 raises oxytocin in humans ⁵⁰, but co-administration has not been tested.
• BPC-157 or TB-500: no direct interaction data exist.
• Avoid redundant combinations: kisspeptin-10 with GnRH analogs or other kisspeptin isoforms hits the same receptor or pathway. Kisspeptin-54 has a longer half-life and crosses the blood-brain barrier better ⁹, so combining isoforms offers no benefit.
• Dopamine agonists: can be used as rescue rather than as competing agents ⁴.

No kisspeptin-10 product is FDA- or EMA-approved for any indication, and human research remains investigational ². It is not a controlled substance under the US Controlled Substances Act, but it is not an approved drug or supplement ingredient.

In sports, kisspeptin-10 is on the WADA 2024 Prohibited List as a peptide hormone because it raises LH, FSH, and testosterone ⁸. Validated LC-HRMS urine assays can detect native kisspeptin-10, several peptide fragments, and an oxidation product, so anti-doping detection is established ⁸. The first marketed drug acting on the kisspeptin/neurokinin B pathway, fezolinetant, was approved for menopausal vasomotor symptoms, showing regulatory receptivity to this axis, but kisspeptin agonism itself remains at the human-experimental stage ⁷¹.

Short-term human exposure has been well tolerated in small studies, and a 14-day IV toxicology study in dogs found a no-observed-adverse-effect level of 1,000 mcg/kg/day ². The main safety questions involve repeated or prolonged exposure.

• Tachyphylaxis: continuous infusion loses the gonadotropin response within a day to 5 days ².
• Vascular and cardiac signals: kisspeptin-10 constricts small blood vessels, promotes histamine-mediated skin edema ²⁵, and in mice accelerates atherosclerotic plaque progression ²⁴. In human cardiac fibroblasts it increases collagen and suppresses collagen-degrading enzymes, a pro-fibrotic signature ²⁷.
• Testicular safety: prepubertal rats given repeated doses showed dose-dependent Leydig cell degeneration and lower testosterone ⁴¹, but a separate adult-rat model found protection against cisplatin-induced testicular oxidative damage ⁴². The divergence is unresolved.
• Pubertal timing: pulsatile dosing advanced first menstruation by about 3.3 months in prepubertal monkeys ⁴⁷.
• Pregnancy: kisspeptin is a core placental regulator, and no exogenous-use safety data exist ⁴⁰.
• Cancer direction: some breast cancer lines show kisspeptin-10-driven invasion via EGFR transactivation ²², while ovarian and triple-negative breast cancer models show growth suppression ¹⁷. Until biomarkers can separate these responses, hormone-sensitive malignancy is treated as a contraindication.
• PCOS and kidney disease: elevated endogenous kisspeptin creates unpredictable or blunted responses ⁵.

Before and during research use, the literature emphasizes LH, FSH, testosterone or estradiol, glucose, blood pressure, and lipid monitoring ².