Kisspeptin: What It Is, Where to Get It Prescribed, and What It Costs

Kisspeptin is a family of peptides encoded by the KISS1 gene. A precursor is cut into kisspeptin-54 and shorter fragments — kisspeptin-14, -13 and -10 — that share the same ten-amino-acid tail. That tail binds the receptor, KISS1R (older papers call it GPR54), which is why the ten-amino-acid fragment is active on its own. The product on this page is kisspeptin-10: the shortest active form, not the full-length hormone used in most of the human trials below. That distinction comes up again.

In the body, kisspeptin is released by hypothalamic neurons and acts on the neurons that make gonadotropin-releasing hormone, GnRH. GnRH tells the pituitary to release luteinising hormone (LH) and follicle-stimulating hormone (FSH), which drive testosterone production in the testes and oestrogen production and ovulation in the ovaries. Kisspeptin is not a sex hormone and does not act on the gonads; it is the upstream signal that sets the axis in motion.

The gene was found in 1996 in Hershey, Pennsylvania, as a suppressor of melanoma spread (Journal of the National Cancer Institute, 1996) and named KiSS-1 after the town's chocolate. Its reproductive role was recognised in 2003, when two groups reported in the New England Journal of Medicine and in PNAS that people born with a non-functioning KISS1R receptor do not go through puberty and have low LH, FSH and sex hormones.

Kisspeptin is not testosterone and not an anabolic agent. It adds no hormone from outside; the research describes it prompting the body's own pituitary and gonads. It is not a treatment for erectile dysfunction, and it is not an approved fertility drug — the fertility work is investigational and used the 54-amino-acid form under trial conditions.

The core mechanism, established in humans. Kisspeptin binds KISS1R on GnRH neurons, which release GnRH to the pituitary. A 2005 paper in the Journal of Clinical Endocrinology and Metabolism from the Imperial College group reported that intravenous kisspeptin-54 in healthy men raised LH, FSH and testosterone dose-dependently. Work with kisspeptin-10 in healthy men, in the same journal in 2011, reported a rise in LH, more frequent LH pulses and a rise in testosterone after a single bolus or short infusion. Hormone changes appear within the hour.

In women, the same signal triggers ovulation. The 2007 JCEM paper reported that the LH response to subcutaneous kisspeptin-54 in healthy women was greatest in the days before ovulation. That is the basis of the IVF trigger work: a kisspeptin injection can prompt the woman's own LH surge rather than substituting hCG for it.

Kisspeptin receptors are also found in limbic regions involved in emotion and reward. A 2017 paper in the Journal of Clinical Investigation used functional MRI in healthy men during a kisspeptin-54 infusion and reported greater activation of these structures in response to sexual and couple-bonding images, alongside reduced negative mood; a 2018 follow-up in JCI Insight reported changes in resting brain connectivity. This is a direct action on the brain, separate from the hormone changes, and it is the mechanism behind the sexual-desire trials.

Kisspeptin behaves differently depending on how continuously the receptor is exposed. Animal work reviewed by the FDA describes continuous high-dose exposure producing an initial LH surge and then a return to baseline despite the infusion continuing, while intermittent lower-dose exposure produced repeatable LH pulses. The Imperial group saw the same in women with hypothalamic amenorrhoea: twice-daily subcutaneous kisspeptin-54 for two weeks stimulated the axis and then the response faded (JCEM 2009), whereas twice-weekly injections for eight weeks sustained it (Clinical Pharmacology and Therapeutics 2010). This phenomenon, tachyphylaxis, is why a kisspeptin schedule is built around gaps.

The best-characterised finding. In healthy men, intravenous kisspeptin-54 and kisspeptin-10 are reported to raise LH and testosterone acutely and to increase LH pulse frequency. A 2013 paper in Clinical Endocrinology reported the same for intravenous kisspeptin-10 in men with type 2 diabetes and mild biochemical hypogonadism. These were mechanistic studies over hours, not treatment trials over months, and every one used the intravenous route.

Women whose periods have stopped because of low body weight, stress or over-training have a suppressed axis with intact ovaries. The 2009 and 2010 Imperial studies reported that kisspeptin-54 injections stimulated LH and FSH release in these women, sustained over eight weeks when injections were spaced out. They were small physiological studies and did not measure whether ovulation or fertility was restored.

The most clinically developed line of work. A 2014 paper in the Journal of Clinical Investigation reported that a single subcutaneous injection of kisspeptin-54, given in place of the usual hCG trigger to women undergoing IVF, produced egg maturation in the large majority and was followed by healthy live births. A 2015 JCEM study extended this to women at high risk of ovarian hyperstimulation syndrome, and a 2017 phase 2 randomised trial in Human Reproduction tested a second dose in that group. These are proper prospective trials, but they used kisspeptin-54 as a one- or two-dose trigger in a fertility clinic.

Two randomised, double-blind, placebo-controlled crossover trials from the same group appeared in JAMA Network Open. The first, in 2022, enrolled premenopausal women with hypoactive sexual desire disorder (HSDD) and reported that a kisspeptin-54 infusion increased activation in sexual-processing brain regions on fMRI, with the treatment described as well tolerated. The second, in 2023, enrolled men with HSDD and reported greater activation of key brain structures during sexual stimuli and a measurable increase in penile tumescence in response to sexual videos, versus placebo. They are real and randomised; they are also small, single-session and intravenous, and measured brain and physiological response rather than months of sexual function in daily life.

Kisspeptin has more human data than almost any other peptide in this category, and almost none of it tests the product on this page as it is used. The physiology is established in people; the IVF and HSDD trials are prospective and, in three cases, randomised. But they used kisspeptin-54 in most cases, the intravenous route in most cases, and single doses or short courses in every case. There are no randomised controlled trials of a subcutaneous kisspeptin-10 course taken over weeks for sexual desire or testosterone support — which is how it is prescribed. The FDA's 2024 review reached the same conclusion for the hypogonadism use: the studies were too small and exploratory, with different routes and frequencies, to support a conclusion on effectiveness.

The prescribing rests on a well-mapped mechanism and clinical experience. The honest framing is "established physiology, promising early trials with a related form, and clinical use," not "proven for what you are buying it for."

• It does not establish that a subcutaneous kisspeptin-10 course raises testosterone or LH in a sustained way. The hormone studies were acute and intravenous, and the response is regimen-dependent.
• It does not establish an effect on sexual desire in daily life. The HSDD trials measured brain activation and physiological arousal during a single infusion.
• It does not establish any benefit in men on testosterone therapy, which suppresses the very system kisspeptin acts on.
• It does not establish safety of repeated subcutaneous kisspeptin-10 injections over months. The FDA found one study of a single subcutaneous kisspeptin-10 dose in healthy women and none by the intramuscular route.
• It does not establish efficacy for any condition as an FDA-approved treatment. It is not approved for anything.

Kisspeptin's hormonal effect is fast and short: in the research, LH rises within an hour and the peptide is cleared in minutes. Prescribers describe the early experience as unremarkable — an injection, no immediate sensation, occasionally a brief flush or headache.

Where changes in desire or mood are reported, this is when prescribers describe them appearing, consistent with the imaging work showing a direct limbic effect rather than a slow hormonal build. Some people report nothing, which is normal.

If the intent is hormonal support, this is when a physician would typically look at bloodwork, because the trial data cannot say what a Monday-to-Friday subcutaneous course does to testosterone over a month. A vial is sized at about four weeks for that reason.

No withdrawal or rebound is described in the human literature. Kisspeptin prompts the body's own axis rather than replacing its output, so there is no suppression to recover from — the opposite of external testosterone. Whether any change in desire persists is not something the trials can answer.

The directions are written in millilitres and in insulin-syringe units because that is what you can read off the barrel. 0.25 mL is 25 units on a U-100 syringe; the number is printed on your medication.

Subcutaneous means into the fat layer, not the muscle. Abdomen and thigh are the usual sites, rotated. Site does not matter for effect, because kisspeptin acts in the brain and pituitary after absorption, not where it is injected.

The two-day gap each week is deliberate. The research describes the response fading under continuous exposure and holding up when exposure is spaced; five doses a week rather than seven builds that gap in. Twenty doses at that pace is four weeks, which is why refills run on a 28-day cycle. One vial per fill, always — not a stockpile. Your physician may direct a different schedule, and if so it is printed on your vial.

Refrigerated, and it ships that way in insulated packaging with ice packs. Kisspeptin-10 is a short peptide sensitive to heat, light and temperature swings, so the label's storage directions are not optional. Beyond-use dating runs from first puncture and is on the label.