Kisspeptin-10
Also known as KP-10, Metastin 45-54, Kisspeptin 112-121
Kisspeptin-10 is the shortest active fragment of kisspeptin, the hypothalamic peptide that sits upstream of GnRH and acts as the master switch for the reproductive axis. People use it to boost LH and testosterone naturally, and research is exploring it for libido and fertility.
Overview
Kisspeptin was identified in the 1990s as a metastasis suppressor, hence its original name metastin, and only later found to be the key regulator of puberty and reproduction. People with mutations in the kisspeptin receptor, KISS1R, fail to go through puberty, and those with overactive signaling go through it early. The full peptide is 54 amino acids, but the final ten residues, kisspeptin-10, carry all of the receptor binding activity. Kisspeptin neurons in the hypothalamus are the cells that actually drive GnRH pulses, integrating signals from sex steroids, energy status, and stress.
Human studies from Imperial College London and elsewhere have shown that kisspeptin-10 injections or infusions reliably raise LH, and to a lesser extent FSH, in healthy men and women, with testosterone rising over the following hours in men. Unlike gonadorelin, which acts directly at the pituitary, kisspeptin works through the body's own GnRH neurons, so the resulting LH release keeps a natural pulsatile shape. Researchers have used it to trigger egg maturation in IVF as a gentler alternative to HCG, with lower rates of ovarian hyperstimulation, and to stimulate the axis in hypothalamic amenorrhea.
The most interesting recent work is on sexual function. Trials published in 2023 found that kisspeptin infusion increased brain activity in sexual and emotional processing regions and improved measures of arousal in men with low sexual desire and in women with hypoactive sexual desire disorder. These were small proof of concept studies, but they suggest kisspeptin has effects beyond hormones. Community use is mostly for boosting LH and testosterone on or off TRT, and honest expectations should account for the fact that chronic high dose exposure can desensitize the receptor just like GnRH.
How it works
Kisspeptin-10 binds KISS1R, a G protein coupled receptor on GnRH neurons in the hypothalamus, causing them to fire and release GnRH into the pituitary portal circulation. The pituitary then secretes LH and FSH in a pulse, and LH drives testosterone or estradiol production in the gonads. Because it acts one step above GnRH, kisspeptin preserves the natural rhythm of the axis and is subject to the same feedback from sex steroids. KISS1R is also expressed in limbic brain regions including the amygdala and hippocampus, which appears to underlie its effects on sexual and emotional processing. At high continuous doses the receptor desensitizes and LH falls, so intermittent dosing is important.
What the research shows
- human RCTSubcutaneous kisspeptin-10 in healthy men produced a dose dependent rise in LH and testosterone within 1-3 hours.
- human RCTKisspeptin-54 as an IVF trigger induced oocyte maturation with a low rate of ovarian hyperstimulation syndrome compared to HCG.
- human pilotKisspeptin infusion increased LH pulse frequency and amplitude in women with hypothalamic amenorrhea.
- human RCTKisspeptin administration enhanced brain responses to sexual stimuli and improved arousal measures in men with low sexual desire.
- human pilotContinuous kisspeptin infusion led to receptor desensitization and suppression of gonadotropins in men, reversible after stopping.
Evidence labels: rodent and in vitro mean no human data for that finding. Human pilot means small, often uncontrolled. Human RCT means randomized and controlled. Clinical means an approved drug with regulatory data.
Dose calculator
U-100 insulin syringeUnits are a volume on the syringe, not an amount of peptide. Concentration changes every time you change the water volume. The standalone calculator explains the math.
Dosing and protocol
community protocols use 50-100 mcg; research doses are weight based and often much higher
4-8 weeks, then reassess LH and testosterone
Morning or evening; some take it 1-2 hours before intimacy for the libido effect. Not tied to meals.
| Vial | Suggested water | Concentration | Low dose draw |
|---|---|---|---|
| 5 mg | 2 mL | 2.5 mg/mL | 2 units |
| 10 mg | 3 mL | 3.333 mg/mL | 1.5 units |
Lyophilized: freezer or fridge, away from light. Reconstituted: fridge 2-8C, use within 4 weeks.
Cautions
- ▲Only works with a functioning hypothalamus, pituitary, and gonads; it cannot override testosterone suppression on TRT.
- ▲High or continuous dosing desensitizes the receptor and can lower LH and testosterone.
- ▲Effects on testosterone are modest in healthy men with normal levels; it does not replace TRT.
- ▲Flushing, headache, and injection site reactions are the main reported side effects.
- ▲Long term safety data does not exist; research exposures have been short.
Commonly stacked with
Frequently asked
Does kisspeptin-10 raise testosterone?
In healthy men, yes, temporarily. LH rises within an hour and testosterone follows over the next few hours, then everything returns to baseline. Whether repeated dosing produces a sustained increase in resting testosterone has not been shown, and the receptor desensitizes if you push it.
Can I use it instead of HCG on TRT?
Not really. Exogenous testosterone suppresses the axis at the pituitary and hypothalamus, and kisspeptin cannot fully override that feedback. HCG bypasses the problem by acting directly on the testes. Kisspeptin may help keep some upstream signaling alive, but expect it to be weaker.
Does it really improve libido?
Small trials suggest it does, through effects on brain regions involved in sexual processing rather than just through hormones. The studies used intravenous infusions in a lab, so whether a subcutaneous dose at home does the same is an open question. Community reports are mixed.
Why is it called kisspeptin?
The gene was discovered in Hershey, Pennsylvania, and named KISS1 after the Hershey Kiss chocolate, with the SS standing for suppressor sequence because it was first identified as a metastasis suppressor. Its role in reproduction was discovered years later.
References
- Kisspeptin-10 stimulates LH and testosterone secretion in healthy men in a dose dependent manner. Journal of Clinical Endocrinology and Metabolism, 2011
- Efficacy of kisspeptin-54 to trigger oocyte maturation in women at high risk of ovarian hyperstimulation syndrome. Journal of Clinical Endocrinology and Metabolism, 2015
- Kisspeptin modulates sexual and emotional brain processing in men with hypoactive sexual desire disorder. JAMA Network Open, 2023
- Kisspeptin and the control of GnRH secretion in humans. Nature Reviews Endocrinology, 2012