Kisspeptin
| Category | Other Peptides |
| Goals | Sexual Health |
| Evidence level | Clinical (human investigational trials; not approved) |
| Legal status | Research-only — not an approved drug |
| FDA status | Not approved; investigational, clinical trials ongoing |
| Half-life | ~4 min (kisspeptin-10); kisspeptin-54 ~28 min (longer-acting fragment) |
| Routes | Intravenous (trials) · Subcutaneous |
| CAS / MW / Sequence | 374675-21-5 · 1302.4 g/mol · YNWNSFGLRF-NH2 (decapeptide, Kp-10) |
| Last reviewed | 2026-06-05 |
In one line
An endogenous reproductive-axis signaling peptide (product of the KISS1 gene) that acts upstream of GnRH to switch on the hypothalamic-pituitary-gonadal (HPG) axis — actively studied in humans for fertility, low desire, and reproductive disorders.
Evidence at a glance
Kisspeptin has a growing body of human clinical-trial data (Imperial College London and others) for hypothalamic amenorrhea, fertility/IVF, and sexual desire — but it is investigational and not approved for any use. Most peptide-market “Kisspeptin-10” is a research chemical. See Evidence Grading Explained and the Disclaimer.
Key Takeaways
- An endogenous neuropeptide encoded by KISS1; kisspeptin-10 (Kp-10) is the short bioactive decapeptide fragment of the larger kisspeptin-54.
- Acts on the KISS1R / GPR54 receptor on GnRH neurons, sitting one step upstream of GnRH in the HPG cascade.
- Stimulating it raises GnRH → LH/FSH → testosterone/estrogen, which is why it is studied for fertility and HPG support.
- Investigational with real human trial data — stronger than purely anecdotal peptides, but not approved.
- Very short half-life (minutes), so practical use is by infusion or the longer kisspeptin-54 fragment.
What Is It
Kisspeptin is a family of peptides produced from the KISS1 gene product (the full peptide is kisspeptin-54; shorter active fragments include kisspeptin-13, -14, and -10). Kisspeptin-10 is the C-terminal decapeptide that retains full activity at the receptor. Discovered in the late 1990s, kisspeptin emerged as a master regulator of puberty and reproduction when loss-of-function mutations in its receptor were found to cause failure of puberty.
Mechanism of Action
- KISS1R (GPR54) agonism (established) — binds the Gq-coupled receptor on hypothalamic GnRH neurons.
- Triggers GnRH release (established) — driving the pituitary to secrete LH and FSH, which in turn stimulate the gonads (testosterone in men; estrogen/ovulation in women).
- Upstream regulator (established) — because it acts above GnRH, it engages the body’s own pulsatile machinery rather than bypassing it, a rationale for fertility uses.
Limitations
Mechanism is well established physiologically, but clinical applications are still being defined in trials. Optimal peptide (Kp-10 vs Kp-54), route, and dosing are unsettled, and benefits for “libido in healthy people” are far less proven than reproductive-axis effects.
Evidence by Outcome
| Outcome | Evidence | Notes |
|---|---|---|
| Stimulates LH/FSH (HPG activation) | Clinical | Reliably raises gonadotropins in human studies |
| Hypothalamic amenorrhea / ovulation | Clinical | Trials in women with reproductive dysfunction |
| Fertility / IVF (triggering egg maturation) | Clinical | Studied as a safer ovulation trigger vs hCG (lower OHSS risk) |
| Sexual desire / arousal | Clinical (preliminary) | Imperial College fMRI/behavioral studies in men and women |
| Testosterone support in men | Clinical / Preclinical | Raises LH/testosterone acutely; long-term use not established |
Reported Dosing
Not medical advice
No approved dose exists; clinical trials use research protocols (often IV infusion). Community/research figures below are not medical recommendations. See Reconstitution & Dosing Math and Injection Technique.
| Form | Setting | Route | Notes |
|---|---|---|---|
| Kisspeptin-10 | Research/trials | IV infusion or SC | Very short-acting; infusion used to sustain effect |
| Kisspeptin-54 | Trials | SC | Longer-acting fragment preferred for sustained dosing |
Pharmacokinetics
Kisspeptin-10 has a very short half-life of ~4 minutes, which limits practical use to infusion; kisspeptin-54 is longer-acting (~28 min subcutaneous) and is generally the clinical candidate for sustained dosing. Bioengineered long-acting kisspeptins are an active research area. See Half-Life & Pharmacokinetics.
Side Effects & Risks
- Generally well tolerated in short clinical studies; no major adverse signal reported at trial doses.
- Possible injection-site reactions; theoretical effects on the menstrual cycle / hormonal axis with repeated dosing.
- Long-term safety is not established — human data is short-term and trial-based.
- Sourcing risk: research-chemical “Kisspeptin-10” has variable identity/purity — see Sourcing and Red Flags & Scams.
- Anyone using it for hormonal goals should consider Bloodwork & Monitoring; see also Side Effects & Risk Management.
Cycling
No established cycling protocol. Because it engages the HPG axis, hormonal monitoring is sensible if used repeatedly, but evidence-based guidance does not exist. See Cycling.
Stacks It Appears In
- Discussed in HPG-support contexts alongside Gonadorelin (which acts one step downstream, at the pituitary). The two have related but distinct targets.
Comparisons
- Gonadorelin — gonadorelin is GnRH and acts directly on the pituitary; kisspeptin acts upstream, telling GnRH neurons to fire. Kisspeptin works “with” the natural pulse generator; gonadorelin replaces/mimics the GnRH signal itself.
Sourcing & Quality
Sold as an unapproved research chemical; identity and purity are not guaranteed. Vet any product critically: How to Read a CoA, Red Flags & Scams, Sourcing. Reconstitution and storage: Reconstitution & Dosing Math, Storage & Handling. No vendors are endorsed here.
Legal & Regulatory Status
(As of 2026-06-05.) Kisspeptin is not an approved drug; it is investigational, with ongoing human clinical trials (notably for hypothalamic amenorrhea, fertility, and sexual desire). Material sold as “Kisspeptin-10” is a research chemical, not approved for human use. See Regulatory & Legal Status.
FAQ
Is Kisspeptin approved? No. It is investigational, with active clinical trials, but not FDA-approved for any indication.
How is it different from Gonadorelin? Kisspeptin acts upstream of GnRH (it tells GnRH neurons to fire); Gonadorelin is GnRH and acts directly on the pituitary.
Why is it studied for fertility? As an ovulation trigger it can mature eggs with potentially lower risk of ovarian hyperstimulation syndrome than hCG, and it can restart the axis in some reproductive disorders.
Kisspeptin-10 or -54? Kp-10 is the short active fragment but extremely short-acting (~4 min); Kp-54 lasts longer (~28 min) and is the usual clinical candidate for sustained dosing.
References
- Dhillo W.S. et al. (Imperial College London) — human studies on kisspeptin, LH secretion, sexual/emotional brain processing, and fertility.
- de Roux N. et al. (2003) and Seminara S.B. et al. (2003) — GPR54/KISS1R loss-of-function and failure of puberty (foundational receptor work). PNAS / NEJM.
- Abbara A. et al. — kisspeptin as an ovulation trigger in IVF and in hypothalamic amenorrhea. J. Clin. Endocrinol. Metab. / JCI.
- Reviews on kisspeptin and the HPG axis in reproductive neuroendocrinology.
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