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Kisspeptin: real science, wrong molecule?

Human kisspeptin studies are among the best in this field: IVF, sexual desire, functional MRI. But almost all use single doses of kisspeptin-54 (subcutaneous injection or intravenous infusion) in a clinical or research setting. What circulates on the market is something else.

Published October 9, 2026 · 2 min read · 15 sources

Why kisspeptin draws interest

Kisspeptin is the switch that triggers GnRH release in the hypothalamus, and with it the whole reproductive axis. Its role was uncovered in 2003, when mutations in its receptor (GPR54) turned out to cause hypogonadotropic hypogonadism and absent puberty89. The natural kisspeptins, 54, 14 and 13 amino acids long, had been isolated from human placenta in 200110. A group at Imperial College London has produced much of the human research, published in leading journals123. In 2005, an IV infusion of kisspeptin-54 raised LH, FSH and testosterone in healthy men11.

Fertility: the strongest data

In 2014, a single subcutaneous injection of kisspeptin-54 triggered oocyte maturation in women undergoing IVF; in that first study (53 women), the clinical pregnancy rate was 23%1. In 2015, in 60 women at high risk of ovarian hyperstimulation syndrome, no moderate or severe OHSS was observed, and the live-birth rate per transfer was 45%; it was an open-label phase 2 trial, randomized only between doses and without a control group2. In 2017, a randomized, placebo-controlled phase 2 trial in 62 high-risk women found that a second administration of kisspeptin-54 improved mature-oocyte yield: 71% versus 45% reached the study target13.

Sexual desire: functional MRI

In 29 healthy men, kisspeptin modified brain processing of sexual and emotional stimuli3. In women with hypoactive sexual desire (32 participants), an IV infusion of kisspeptin-54 changed brain activity on functional MRI4. In men with hypoactive sexual desire (32 participants), it was associated with up to 56% more penile tumescence than placebo5.

23%clinical pregnancy in the first IVF study (53 women)1
0cases of moderate or severe OHSS in 60 high-risk women2
32participants in each hypoactive-desire study45

The gap: a different molecule, a different route

Three differences separate those studies from the market. First, the molecule: the studies used kisspeptin-54; the form nominated for US compounding is kisspeptin-10, a shorter isoform6. Kisspeptin-10 is the minimal sequence with full activity, but its human studies were IV boluses and infusions lasting hours in healthy men12. Second, route and setting: single infusions or injections, in IVF units or research centers, with monitoring; even in women with hypothalamic amenorrhea, use was by controlled IV infusion14. Third, the outcomes: for sexual desire, the main results are functional MRI changes, not sustained clinical efficacy45.

The FDA keeps kisspeptin-10 in Category 2 of its 503A list and explains that "FDA has no, or only limited, safety-related information for the proposed routes of administration"67. In sport, the World Anti-Doping Agency lists "kisspeptin and its agonist analogues" among testosterone-stimulating peptides in males, prohibited at all times15.

Sources

  1. Jayasena CN, et al. Kisspeptin-54 triggers egg maturation in women undergoing in vitro fertilization. J Clin Invest. 2014;124(8):3667-77. PubMed 25036713 ↗
  2. Abbara A, et al. Efficacy of kisspeptin-54 to trigger oocyte maturation in women at high risk of ovarian hyperstimulation syndrome (OHSS) during in vitro fertilization (IVF) therapy. J Clin Endocrinol Metab. 2015;100(9):3322-31. PubMed 26192876 ↗
  3. Comninos AN, et al. Kisspeptin modulates sexual and emotional brain processing in humans. J Clin Invest. 2017;127(2):709-719. PubMed 28112678 ↗
  4. Thurston L, et al. Effects of Kisspeptin Administration in Women With Hypoactive Sexual Desire Disorder: A Randomized Clinical Trial. JAMA Netw Open. 2022;5(10):e2236131. PubMed 36287566 ↗
  5. Mills EG, et al. 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;6(2):e2254313. PubMed 36735255 ↗
  6. U.S. Food and Drug Administration. Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the Federal Food, Drug, and Cosmetic Act (categories 1–3). Updated 14 May 2026. fda.gov ↗
  7. U.S. Food and Drug Administration. Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks. fda.gov ↗
  8. de Roux N, Genin E, Carel JC, Matsuda F, et al. Hypogonadotropic hypogonadism due to loss of function of the KiSS1-derived peptide receptor GPR54. Proc Natl Acad Sci U S A. 2003;100(19):10972-6. PubMed 12944565 ↗
  9. Seminara SB, Messager S, Chatzidaki EE, Thresher RR, et al. The GPR54 gene as a regulator of puberty. N Engl J Med. 2003;349(17):1614-27. PubMed 14573733 ↗
  10. Kotani M, Detheux M, Vandenbogaerde A, Communi D, et al. The metastasis suppressor gene KiSS-1 encodes kisspeptins, the natural ligands of the orphan G protein-coupled receptor GPR54. J Biol Chem. 2001;276(37):34631-6. PubMed 11457843 ↗
  11. Dhillo WS, Chaudhri OB, Patterson M, Thompson EL, et al. Kisspeptin-54 stimulates the hypothalamic-pituitary gonadal axis in human males. J Clin Endocrinol Metab. 2005;90(12):6609-15. PubMed 16174713 ↗
  12. George JT, Veldhuis JD, Roseweir AK, Newton CL, et al. Kisspeptin-10 is a potent stimulator of LH and increases pulse frequency in men. J Clin Endocrinol Metab. 2011;96(8):E1228-36. PubMed 21632807 ↗
  13. Abbara A, Clarke S, Islam R, Prague JK, et al. A second dose of kisspeptin-54 improves oocyte maturation in women at high risk of ovarian hyperstimulation syndrome: a Phase 2 randomized controlled trial. Hum Reprod. 2017;32(9):1915-1924. PubMed 28854728 ↗
  14. Jayasena CN, Abbara A, Veldhuis JD, Comninos AN, et al. Increasing LH pulsatility in women with hypothalamic amenorrhoea using intravenous infusion of Kisspeptin-54. J Clin Endocrinol Metab. 2014;99(6):E953-61. PubMed 24517142 ↗
  15. World Anti-Doping Agency. The 2026 Prohibited List (International Standard). Effective 1 January 2026. wada-ama.org ↗

Informational article. It summarizes news, official statements and published studies; it is not medical or legal advice. Sources were checked on the publication date.

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