Kisspeptin-10

Kisspeptin-10 is a peptide fragment from the kisspeptin family, which plays a key role in regulating reproductive hormone signaling.

Experimental and early clinical work has examined kisspeptin fragments in relation to fertility, puberty, and certain endocrine conditions.

Kisspeptin peptides act on the KISS1 receptor (GPR54) in the hypothalamus, stimulating gonadotropin-releasing hormone (GnRH) secretion and, downstream, influencing LH and FSH release from the pituitary.

Kisspeptin-10 captures a portion of this activity and is used in some experimental protocols to probe or modulate reproductive axis function.

Clinical studies have examined kisspeptin-based interventions in fertility and reproductive endocrinology, but routine therapeutic use of kisspeptin-10 is not widely established.

Catalog listings typically reflect research or experimental interest rather than standardized fertility protocols.

Kisspeptin is named on the WADA Prohibited List in sub-section S2.2.1, headed "Testosterone-stimulating peptides in males." The sub-section lists four bullets — chorionic gonadotrophin (CG), luteinizing hormone (LH), "gonadotrophin-releasing hormone (GnRH, gonadorelin) and its agonist analogues (e.g. buserelin, deslorelin, goserelin, histrelin, leuprorelin, nafarelin and triptorelin)," and "kisspeptin and its agonist analogues." The listing is at the level of the family, not the fragment: kisspeptin-10 is an agonist form of kisspeptin and is covered by that bullet, and the sub-section's "including, but not limited to" opening captures analogues that have not been individually written down. All S2 substances are non-Specified Substances, so the default first-violation sanction is four years.

The male-only condition, stated precisely. The prohibition is not universal — it is scoped by the sub-section heading itself, "Testosterone-stimulating peptides in males." WADA rewrote this category for the 2024 List so that it is defined by effect rather than by receptor pharmacology: USADA's summary of the change states that "WADA has reworded this section to clarify that testosterone-stimulating peptides (previously Gonadotrophin-Releasing Hormone (GnRH) agonist analogs) are prohibited in males" (USADA athlete advisory, 2024 Prohibited List). Kisspeptin's arrival in the sub-section dates from that same rewrite — the advisory records that "histrelin and kisspeptin were both added as examples to the Prohibited List as well." In a male athlete, kisspeptin-10 drives GnRH release and therefore LH and testosterone — which is the entire rationale for the listing. In a female athlete it does not raise testosterone in the same way and is not prohibited on that basis. Two cautions attach to that asymmetry: it is specific to this sub-section and does not generalise to other parts of the List, and WADA's 2026 Monitoring Program separately tracks "gonadotrophin-releasing hormone (GnRH) analogues in females under 18 years only," which is typically how a listing change begins.

Detection. Kisspeptin-10 is not a hypothetical target. Colpaert and colleagues describe it as a peptide "capable of increasing circulating follicle-stimulating hormone, luteinizing hormone and testosterone levels in humans" whose "testosterone-increasing effect indicates potential misuse in sports," and report "the successful validation of an initial testing procedure (screening) and a confirmation procedure for kisspeptin-10 in urine using liquid chromatography-mass spectrometry" (Colpaert et al., Biomed Chromatogr 2024).

The method design answers the obvious evasion argument. Kisspeptin-10 clears very fast — the authors cite "a rapid elimination time of only 30 min after injection (in rats)" — so they incubated it in human serum to generate metabolites and added four of them, "corresponding to peptide fragments y9, y8, y7 and y5," to the screening procedure in full-scan mode. A short half-life is not a short detection window once the metabolites are on the target list.

The same paper also analysed "a black-market vial of kisspeptin-10," which "contained no unexpected impurities, although it appeared to have undergone more degradation than the purchased reference standard" — and identified a degradation product arising from "oxidation of the tryptophan residue into a kynurenine residue." Degraded product is neither safer nor less prohibited.

Because kisspeptin-10 has no established therapeutic indication in routine practice, there is effectively no clinical basis on which a therapeutic use exemption could be granted for a male athlete.

Reported adverse effects have generally been mild, such as injection-site discomfort or transient hormone-related symptoms, but larger and longer-term datasets are limited.

Kisspeptin-10 stimulates GnRH release. It is being explored as a safer alternative to HCG for maintaining testicular function.

This information summarizes commonly discussed research practices.

Kisspeptin-10 is supplied as a lyophilized powder for reconstitution and sold as a research reagent, with no pharmaceutical-grade product available. Its clinical relatives are more advanced: TAK-448 is an oligopeptide analog of the fully active 10-amino-acid C-terminus of kisspeptin-54 that reached phase 1 trials as an androgen-deprivation candidate, with a median terminal half-life of 1.4 to 5.3 hours and depot formulations tested in prostate cancer patients (PMID 24762108). That development path — toward suppression, not stimulation — is the clearest signal of how the molecule behaves under sustained exposure.

In fertility research kisspeptin is studied as an alternative to existing triggers rather than an addition to them. The interest is in substituting it for hCG or a GnRH agonist to mature oocytes during IVF, on the reasoning that evoking the body's own LH surge may carry a lower risk of ovarian hyperstimulation syndrome than a long-acting exogenous surge (PMID 36147569).

Studies of kisspeptin-10 have examined hormone profiles, ovulatory responses, and diagnostic potential in reproductive medicine. The evidence base is specialized and still evolving.

For deeper dives on this peptide, see:

• Kisspeptin-10 benefits and areas of interest
• Kisspeptin-10 side effects and safety context
• Kisspeptin-10 dosing concepts (educational)
• Kisspeptin-10 research and evidence overview

Does kisspeptin-10 actually do anything in humans? Yes, and it has been measured. Intravenous boluses of 0.01 to 3.0 µg/kg in healthy men produced a rapid, dose-dependent rise in LH, peaking at 1 µg/kg with LH going from 4.1 to 12.4 IU/L at 30 minutes. A 22.5-hour infusion at 4 µg/kg·h raised LH from 5.4 to 20.8 IU/L and testosterone from 16.6 to 24.0 nmol/L (PMID 21632807).

Does more produce a bigger response? No — the acute dose-response has a peak. In the same study, 3 µg/kg elicited a reduced LH response compared with 1 µg/kg.

Can it be used to raise testosterone long term? The evidence points the other way. In phase 1 studies of the kisspeptin analog TAK-448, a single bolus raised testosterone roughly 1.3- to 2-fold by 48 hours, but a 14-day continuous infusion above 0.1 mg/day drove testosterone below baseline by 60 hours and to a sustained below-castration level by day 8 (PMID 24762108). Pulsatile signalling stimulates the GnRH axis; continuous signalling desensitizes it.

Does it work the same way in women? No. Comparing healthy men and women, men showed elevated LH from 0.3 nmol/kg and FSH from 1.0 nmol/kg, while women in the follicular phase showed no gonadotropin change at the doses tested — though women in the preovulatory phase did respond (PMID 21976724). Sex and cycle phase determined whether the peptide did anything at all.

Is it approved for anything? No. It is a physiology research tool with no approved indication in any jurisdiction. The most developed clinical hypothesis is as an IVF oocyte-maturation trigger, still under investigation (PMID 36147569).