Kisspeptin is sold online as a libido peptide, often with the claim that it raises testosterone. Unlike many peptides in that market, it has real human research behind it. That research is careful and mostly short: single infusions, in hospital, measured in hours. This page sets out what it shows, and it sits under the sexual health goal.
What kisspeptin does
Kisspeptin is a hormone the body makes. It acts on GnRH neurons in the hypothalamus, and the GnRH they release tells the pituitary gland to release LH and FSH, the hormones that drive the testes and ovaries [3]. It comes in several lengths; kisspeptin-10 and kisspeptin-54 are the two used in most human studies.
A 2015 study compared them in healthy men, with five men per dose group [3]. Given intravenously for 3 hours, kisspeptin-10 and kisspeptin-54 raised LH and FSH to similar levels. GnRH itself was more potent: LH was about 3-fold higher on GnRH than on kisspeptin-10, and about 2-fold higher than on kisspeptin-54.
Does it raise testosterone?
In the short term, yes. A 2026 study gave 15 healthy men kisspeptin-10 under the skin by continuous pump [4]. Eight-hour infusions raised LH, FSH and testosterone in a dose-dependent way compared with vehicle (P<.0001).
Longer use was less simple. With a pump running for 5 days straight, testosterone stayed higher, but LH and FSH fell back to vehicle levels. Daily 8-hour infusions for 12 days kept LH raised, by 1.68 units on day 1 and 1.14 on day 12, against a small fall on vehicle [4]. The authors present this as a protocol to develop, not a treatment.
Libido in men
The best-known study randomized 37 men with hypoactive sexual desire disorder, and 32 completed it [1]. Each man had two visits, one with a 75-minute intravenous infusion of kisspeptin-54 and one with placebo, in random order. They watched sexual videos in an MRI scanner.
Kisspeptin changed activity in the brain’s sexual-processing network compared with placebo (Cohen d = 0.81; 95% CI, 0.41 to 1.21). Penile tumescence rose by up to 56% more than on placebo, and men reported more happiness about sex, by 0.63 points [1].
Those are real, measured effects, and they come from a single infusion in a laboratory. The trial did not test whether desire changed at home, over weeks, or with any form a person could take themselves.
Libido in women
The same group ran a matching trial in premenopausal women with hypoactive sexual desire disorder [2]. Forty were randomized and 32 completed both visits. The same 75-minute infusion changed brain activity in response to erotic videos and to attractive faces.
Some of those brain changes tracked how the women felt. Greater hippocampal activity with kisspeptin correlated with baseline distress about sexual function (r = 0.469; P = .007). Kisspeptin was well tolerated, and no adverse effects were reported [2]. One approved drug for this condition in women is covered in the bremelanotide approval and trials.
Fertility and IVF
Kisspeptin’s most advanced use is in IVF. A phase 2 trial gave 60 women at high risk of ovarian hyperstimulation syndrome a single injection of kisspeptin-54 to trigger egg maturation [5]. Doses ranged from 3.2 to 12.8 nmol/kg.
Egg maturation occurred in 95% of women. Across all doses, the live birth rate per embryo transfer was 45%, and no woman developed moderate, severe or critical hyperstimulation [5]. The trial was open-label and had no comparison group on the standard trigger.
What this means for you
Kisspeptin is a hormone with a clear effect on reproductive hormones and early, promising brain and arousal data from single infusions. No human dose for libido has been established, and no study here tested kisspeptin injected by the user at home. For men comparing options, the older melanocortin route is covered in what the PT 141 trials in men found. The legal position of research-only peptides is in are peptides legal.