what is the difference
Kisspeptin-10 and kisspeptin-54
Two lengths of the same reproductive hormone, with the published human work split unevenly between them.
The KISS1 gene makes a precursor protein that the body cuts into several pieces. Kisspeptin-54 is the 54 amino acid product, first described under the name metastin. Kisspeptin-10 is the ten amino acid tail shared by the longer forms, and it is the shortest sequence that still carries the full activity at the receptor. Both act at the same place, on the neurons that release GnRH, which sits at the top of the chain running reproduction: GnRH drives LH and FSH out of the pituitary, and those drive the gonads.
Kisspeptin-10 is the form sold on this market, usually as KP-10. Kisspeptin-54 is the form that carries most of the published human work, including both of the randomised trials that get cited when kisspeptin is discussed in connection with sexual desire. Those trials used an intravenous infusion of the 54 amino acid molecule in a research setting, and this page sets out which study used which form, one at a time.
Not medical advice
This page reports what has been documented about a compound. It is not medical advice, not a diagnosis, not a dosing protocol, and not a recommendation to obtain or use anything described here. Talk to a licensed clinician about anything concerning your health. Read the full disclaimer.
Reviewed against editorial standards Updated
The short answer
The two randomised trials people cite for kisspeptin and sexual desire, published in JAMA Network Open in 2022 and 2023, both used kisspeptin-54 given by intravenous infusion. Neither used kisspeptin-10. Under this site's rules those trials set a tier for kisspeptin-54 and none at all for the shorter fragment.
Kisspeptin-10 has a human record of its own, and it is about reproductive hormone release rather than desire. It is made of small mechanistic studies, several of them with a handful of participants per group, run to characterise how the hormone axis responds.
Side by side
| Property | Kisspeptin-10 | Kisspeptin-54 |
|---|---|---|
| What it is | The ten amino acid tail of the KISS1 gene product, and the shortest sequence carrying full activity at the receptor | The 54 amino acid product of the same gene, first described under the name metastin |
| Names in circulation | KP-10, and metastin is used loosely for it as well, which does not help | KP-54, metastin |
| Which one the desire trials used | Neither of them | Both: the 2022 trial in women and the 2023 trial in men, each an intravenous infusion in a single UK academic centre |
| Size of the desire trials | Not applicable | 40 women randomised with 32 completing, and 37 men randomised with 32 completing |
| Its own published human work | Studies of reproductive hormone release: LH pulse frequency in men, and a comparison of the response in men against the response in women | Work on reproductive hormone release, on triggering egg maturation in IVF, and the two desire trials |
| Scale of that work | Small and mechanistic, with several arms in the single digits per group | Larger in places, including a trial of egg maturation in women undergoing IVF |
| Registrations naming it on ClinicalTrials.gov | 5. Two were withdrawn before enrolling anyone, and the three completed ones are mechanistic studies of pubertal onset and insulin secretion | 19, spread across phase 1 and phase 2, most of them from one US academic centre, with two industry-sponsored phase 2 studies listed as terminated |
| Route used in the published work | Intravenous bolus and infusion, and in one study a subcutaneous bolus | Intravenous bolus and infusion |
| What it is developed as | A research tool for probing the reproductive axis | A fertility and diagnostic tool, which is what the trial programme is shaped around |
| Head-to-head comparison | Compared directly against kisspeptin-54 and against GnRH in healthy men in 2015, at matched infusion rates | Same study: both forms produced similar gonadotrophin levels, and GnRH produced higher levels than either |
| Regulatory position | No approval. DailyMed returns no label for kisspeptin, searched 2 August 2026 | No approval. Same search, same result |
Why the two get mixed up
The word kisspeptin does most of it. The two molecules share a receptor and a ten amino acid business end, and papers, press releases and headlines routinely say kisspeptin without a number even when the study used one specific form. The 2022 and 2023 trials are titled that way: both say kisspeptin in the title and name kisspeptin-54 only in the intervention description [1] [2]. Anyone reading a title, an abstract conclusion or a news summary comes away with the family name.
The registry compounds it. A search on kisspeptin returned 45 registrations on 2 August 2026, and 13 of those are indexed as observational, meaning they measure the kisspeptin a person already makes rather than giving anyone any. Kisspeptin is a hormone the body produces, so a large share of clinical research on it is measurement. Counting all 45 as a trial programme for a purchasable peptide overstates the record twice over: once by including the observational work, and once by folding two molecules into one number.
Then there is the naming. Metastin was the original name for the 54 amino acid form, and it circulates as an alias for the shorter fragment on product listings, so the two can appear under the same three names in the same paragraph. A reader who then finds that kisspeptin-10 is the minimal active sequence has a plausible reason to treat the longer molecule's results as the shorter one's. EVIDENCE-TIERS.md section 1 is explicit that a fragment does not inherit the evidence of the molecule it came out of, and it applies here in both directions.
What the published record covers for each
The desire trials are real, randomised and small, and they are about the longer molecule. A 2022 randomised clinical trial in JAMA Network Open gave premenopausal women with hypoactive sexual desire disorder an intravenous infusion of kisspeptin-54 against placebo and measured brain processing and questionnaire outcomes, with 40 randomised and 32 completing both visits [Human RCT] [1]. A 2023 trial in the same journal used the same molecule and a two-way crossover design in men with the same diagnosis, with 37 randomised and 32 completing [Human RCT] [2].
The longer molecule also carries the fertility work. A 2014 study in the Journal of Clinical Investigation used kisspeptin-54 to trigger egg maturation in women undergoing in vitro fertilisation [Human open-label] [6]. That is the direction the academic programme has taken: a diagnostic and fertility tool rather than a libido drug.
What exists on kisspeptin-10 in people is a different kind of study. A 2011 paper in the Journal of Clinical Endocrinology and Metabolism reported that intravenous kisspeptin-10 raised LH in men and increased the frequency of LH pulses, across arms with a handful of participants each [Human open-label] [3]. A second 2011 paper from the same programme gave kisspeptin-10 to men and to women, again with four to five participants per group, and reported that the gonadotrophin response differed between them [Human open-label] [4].
One study did put the two molecules side by side. A 2015 paper in Human Reproduction gave healthy men vehicle, kisspeptin-10, kisspeptin-54 and GnRH intravenously on separate study days, in a single-blinded placebo-controlled design with five participants per group, and reported that the two kisspeptin forms produced similar gonadotrophin levels while GnRH produced higher ones [Human open-label] [5]. The authors named the sample size as a limitation themselves. That comparison covers one endpoint, gonadotrophin release, in one population, healthy men. Nothing in it extends to the desire endpoints the 2022 and 2023 trials measured.
The registrations line up the same way. Of the five registrations naming kisspeptin-10, two were withdrawn before enrolling anyone and the three that completed are mechanistic studies of pubertal onset and of insulin secretion, none of them about desire [8]. The 19 naming kisspeptin-54 include phase 1 and phase 2 work concentrated in one US academic centre, alongside two industry-sponsored phase 2 studies listed as terminated. A review of the field in 2022 sets out where the clinical interest actually sits, which is in probing and driving the reproductive axis [7].
Our takeA substantial academic programme sits behind kisspeptin, and the part of it people quote most is about the molecule that is not on sale. Anyone citing the JAMA Network Open desire trials for kisspeptin-10 is citing a trial of something else.
Frequently asked questions
Are kisspeptin-10 and kisspeptin-54 the same molecule?
No. Both come out of the KISS1 gene product, and kisspeptin-10 is the ten amino acid tail that the longer forms share, but they are different sequences of different lengths. They act at the same receptor, which is why the two get treated as interchangeable, and a study of one is still a study of one.
Did the kisspeptin desire trials use the form that is sold?
They did not. The 2022 trial in women and the 2023 trial in men, both in JAMA Network Open, used an intravenous infusion of kisspeptin-54 [1] [2]. The form sold on this market is kisspeptin-10. Those trials set a tier for kisspeptin-54 and none for kisspeptin-10.
So what has kisspeptin-10 been studied for in people?
Reproductive hormone release, mostly. A 2011 study reported that intravenous kisspeptin-10 raised LH and increased LH pulse frequency in men [3], and a second 2011 study from the same programme compared the response in men against the response in women [4]. Both are small, with arms in the single digits, and both are mechanistic rather than clinical.
Does kisspeptin have 45 clinical trials?
It has 45 registrations, which is a different statement. Thirteen of them are indexed as observational, meaning they measure the kisspeptin a person already produces rather than giving anyone any, and the rest are split across two molecules and several unrelated questions. Five name kisspeptin-10, of which two were withdrawn before enrolling anyone [8].
Has anyone compared the two forms directly?
Once, in healthy men. A 2015 study in Human Reproduction gave vehicle, kisspeptin-10, kisspeptin-54 and GnRH intravenously on separate days, with five participants per group, and reported similar gonadotrophin levels from the two kisspeptin forms and higher levels from GnRH [5]. That is one endpoint in one population, and the authors named the sample size as a limitation.
Is kisspeptin an approved drug?
Not in the United States, in either form. DailyMed, the FDA labelling database, returned no label for kisspeptin when it was searched on 2 August 2026 [9]. The academic programme behind it has been oriented towards fertility and diagnostic use rather than towards a desire drug [6] [7].
References
- Thurston L, Hunjan T, Ertl N, Wall MB, Mills EG, Suladze S, Patel B, Alexander EC, Muzi B, Bassett PA, Rabiner EA, Bech P, Goldmeier D, Abbara A, Comninos AN, Dhillo WS. Effects of Kisspeptin Administration in Women With Hypoactive Sexual Desire Disorder: A Randomized Clinical Trial. JAMA Netw Open. 2022. PMID 36287566 DOI 10.1001/jamanetworkopen.2022.36131
- Mills EG, Ertl N, Wall MB, Thurston L, Yang L, Suladze S, Hunjan T, Phylactou M, Patel B, Muzi B, Ettehad D, Bassett PA, Howard J, Rabiner EA, Bech P, Abbara A, Goldmeier D, Comninos AN, Dhillo WS. Effects of Kisspeptin on Sexual Brain Processing and Penile Tumescence in Men With Hypoactive Sexual Desire Disorder: A Randomized Clinical Trial. JAMA Netw Open. 2023. PMID 36735255 DOI 10.1001/jamanetworkopen.2022.54313
- George JT, Veldhuis JD, Roseweir AK, Newton CL, Faccenda E, Millar RP, Anderson RA. Kisspeptin-10 is a potent stimulator of LH and increases pulse frequency in men. J Clin Endocrinol Metab. 2011. PMID 21632807 DOI 10.1210/jc.2011-0089
- Jayasena CN, Nijher GM, Comninos AN, Abbara A, Januszewki A, Vaal ML, Sriskandarajah L, Murphy KG, Farzad Z, Ghatei MA, Bloom SR, Dhillo WS. The effects of kisspeptin-10 on reproductive hormone release show sexual dimorphism in humans. J Clin Endocrinol Metab. 2011. PMID 21976724 DOI 10.1210/jc.2011-1408
- Jayasena CN, Abbara A, Narayanaswamy S, Comninos AN, Ratnasabapathy R, Bassett P, Mogford JT, Malik Z, Calley J, Ghatei MA, Bloom SR, Dhillo WS. Direct comparison of the effects of intravenous kisspeptin-10, kisspeptin-54 and GnRH on gonadotrophin secretion in healthy men. Hum Reprod. 2015. PMID 26089302 DOI 10.1093/humrep/dev143
- Jayasena CN, Abbara A, Comninos AN, Nijher GM, Christopoulos G, Narayanaswamy S, Izzi-Engbeaya C, Sridharan M, Mason AJ, Warwick J, Ashby D, Ghatei MA, Bloom SR, Carby A, Trew GH, Dhillo WS. Kisspeptin-54 triggers egg maturation in women undergoing in vitro fertilization. J Clin Invest. 2014. PMID 25036713 DOI 10.1172/JCI75730
- Anderson RA, Millar RP. The roles of kisspeptin and neurokinin B in GnRH pulse generation in humans, and their potential clinical application. J Neuroendocrinol. 2022. PMID 34962670 DOI 10.1111/jne.13081
- US National Library of Medicine, ClinicalTrials.gov. Registration search run through the v2 API on 2 August 2026: kisspeptin returns 45 registrations, 13 of them indexed as observational; kisspeptin-10 returns 5, of which NCT04532801 and NCT05456854 are withdrawn and NCT03286517, NCT03315325 and NCT03771326 are completed; kisspeptin-54 returns 19. ClinicalTrials.gov. 2026. Registry search
- US National Library of Medicine, DailyMed. FDA labelling database, searched for kisspeptin on 2 August 2026, which returned no labels under that name in either form. DailyMed, National Library of Medicine. 2026. DailyMed search