Kisspeptin-10
Kisspeptin-10 (metastin 45-54) · KP-10 · Kp-10 · Metastin 45-54 · KISS1 (112-121)
Upstream GnRH trigger — the switch that makes the hypothalamus fire and the pituitary release LH.
Typical dose
50 mcg
3x weekly on non-consecutive days
Range
10–100
mcg
Half-life
4 min
see Dosing
Evidence
Early human
Subcutaneous · Intravenous
What it is
Kisspeptin-10 is the ten-amino-acid C-terminal fragment of kisspeptin, the KISS1 gene product that sits at the very top of the reproductive axis. Kisspeptin neurons are the gatekeepers of puberty and of GnRH pulsatility; without functional KISS1R signalling the axis does not start.
In humans, a single intravenous or subcutaneous bolus of kisspeptin-10 reliably produces an LH pulse in men, and repeated bolus dosing increases LH pulse frequency. Separate imaging work has shown kisspeptin modulating limbic responses to sexual and emotional stimuli, and a randomised trial in men with hypoactive sexual desire found effects on sexual brain processing and penile tumescence — which is why it turns up in a sexual-health context as well as an HPTA one.
What it is not is a proven post-cycle therapy. The half-life is roughly four minutes, the LH response to continuous exposure desensitises within hours, and no trial has shown that kisspeptin restores testosterone in men suppressed by anabolic steroids. Treat community protocols as extrapolation from acute physiology studies, not as an evidence-based recovery plan.
How it works
Kisspeptin-10 binds KISS1R (GPR54) on GnRH neurons in the hypothalamus, depolarising them and triggering GnRH release. That GnRH pulse drives the pituitary to secrete LH and, to a lesser extent, FSH, which in turn drives testicular testosterone production. It acts one step above everything else in the recovery toolkit: gonadorelin is GnRH itself and triptorelin a long-acting synthetic GnRH agonist analogue, hCG mimics LH at the testis, and kisspeptin is the signal that produces GnRH in the first place.
The catch is built into the same physiology. GnRH neurons are designed to respond to pulses, not to a constant signal, so sustained or too-frequent kisspeptin exposure desensitises the response rather than amplifying it. Combined with a plasma half-life measured in minutes, that makes pulsatile, spaced dosing the only approach that makes mechanistic sense.
Dosing
There is no validated human protocol at these doses — published studies used intravenous bolus or infusion dosed by body weight, and subcutaneous microgram protocols are community extrapolation. Spacing doses matters more than raising them, because continuous exposure desensitises the response.
Reconstitution calculator
Pre-loaded with Kisspeptin-10’s vial size, water volume and typical dose. Change anything.
Typical: 50 mcg · range 10–100
Draw to
5 u
0.05 mL · 50 mcg
Concentration
1 mg/mL
10 mcg per unit
Doses per vial
100
Vial lasts
7.7 months
Draw to 5 units on the barrel.
Once mixed
Refrigerated at 2-8°C, use within about 3-4 weeks. Kisspeptin-10 is a short unprotected peptide and degrades faster in solution than most; do not freeze-thaw it. This vial would take about 7.7 months to finish — check that against the storage window before mixing the whole thing.
5 mL of bacteriostatic water into a 5 mg vial gives 1,000 mcg/mL, so 50 mcg is 5 units on a U-100 pin. The deliberately large dilution is because the doses are tiny — reconstituting into 1-2 mL makes an accurate 50 mcg draw impossible. Run the water down the glass wall and swirl gently.
Storage
Before mixing
Refrigerated at 2-8°C it is stable for 2+ years; sealed and dry it tolerates a few weeks at room temperature.
After mixing
Refrigerated at 2-8°C, use within about 3-4 weeks. Kisspeptin-10 is a short unprotected peptide and degrades faster in solution than most; do not freeze-thaw it.
Reported benefits
- ▪Produces a genuine, measurable LH pulse in men after a single dose
- ▪Acts upstream of GnRH, so the pituitary and testes do the work rather than being bypassed
- ▪Increases LH pulse frequency with repeated bolus dosing
- ▪Effects on sexual brain processing and penile tumescence shown in randomised human work
- ▪Drives the pituitary rather than bypassing it, so it avoids the Leydig-cell desensitisation and negative feedback that come with sustained hCG
- ▪Very well tolerated in the doses used in human studies
Side effects
- ▪Generally minimal in trials — the main reported issues are injection site reactions
- ▪Tachyphylaxis: the LH response fades with continuous or over-frequent dosing
- ▪Occasional transient flushing or mild nausea at higher doses
- ▪Short, unpredictable duration of effect because of the ~4 minute half-life
- ▪No long-term human safety data at any dose or duration
- ▪Unstudied effects on oestradiol and prolactin when the axis is being driven repeatedly
Do not use if
- ▪Any hormone-sensitive cancer, including prostate cancer
- ▪Pregnancy or active fertility treatment outside clinical supervision
- ▪Primary hypogonadism, where the testes cannot respond regardless of how much LH is produced
- ▪Concurrent GnRH agonist therapy such as triptorelin or leuprolide
Evidence level — Early human
Small or early-phase human studies only.
Not approved anywhere; used in academic human physiology research and sold elsewhere as a research chemical.
Commonly run with
Kisspeptin-10 FAQ
Does kisspeptin work for post-cycle recovery?+
There is no human trial showing it restores testosterone in men suppressed by anabolic steroids. It reliably generates an LH pulse in healthy men, which is the mechanistic argument, but that is not the same as demonstrated recovery. Anyone using it for PCT is running an experiment, not a protocol.
How is it different from gonadorelin or hCG?+
Kisspeptin sits one step higher: it tells GnRH neurons to fire, gonadorelin is GnRH itself acting on the pituitary, and hCG bypasses both to act as LH directly at the testis. Stacking kisspeptin with a GnRH agonist is redundant, and running it alongside hCG makes little sense because hCG's negative feedback suppresses the very axis kisspeptin is trying to drive.
Why is the half-life so short and does it matter?+
Kisspeptin-10 is an unprotected decapeptide cleared in about four minutes. It matters less than it sounds, because the LH pulse it triggers outlasts the peptide by hours. What it does mean is that continuous or very frequent dosing is counterproductive — GnRH neurons respond to pulses and desensitise to a constant signal.
Will it raise testosterone measurably?+
In men with an intact axis, an LH rise after dosing has been shown repeatedly, and testosterone follows the LH. Whether that translates into a sustained higher baseline over weeks has not been established, and if you already have normal LH there is little headroom for it to add.
Does it help libido on its own?+
Human imaging work shows kisspeptin altering limbic responses to sexual stimuli, and a randomised trial in men with hypoactive sexual desire found effects on sexual brain processing and penile tumescence. Those studies used intravenous infusion of kisspeptin-54 rather than subcutaneous kisspeptin-10, so the read-across to a 50 mcg pin is an assumption rather than a finding.
References
- 1.Kisspeptin-10 is a potent stimulator of LH and increases pulse frequency in men — The Journal of Clinical Endocrinology and Metabolism (2011) PMID 21632807
- 2.Kisspeptin-54 stimulates the hypothalamic-pituitary gonadal axis in human males — The Journal of Clinical Endocrinology and Metabolism (2005) PMID 16174713
- 3.Kisspeptin modulates sexual and emotional brain processing in humans — The Journal of Clinical Investigation (2017) PMID 28112678
- 4.Effects of Kisspeptin on Sexual Brain Processing and Penile Tumescence in Men With Hypoactive Sexual Desire Disorder: A Randomized Clinical Trial — JAMA Network Open (2023) PMID 36735255
More hpta & fertility
Gonadorelin
Native GnRH decapeptide, now the usual compounded stand-in for hCG on TRT.
200 mcg · 1-2x daily
hCG
LH-mimic that keeps the testes producing while exogenous androgens shut the axis down.
500 IU · Every other day, or 2-3x per week
hMG
Urine-derived FSH plus LH activity, added to hCG when sperm counts will not recover.
75 IU · 3x per week
Triptorelin
Long-acting GnRH agonist taken as one microdose to fire off a large LH and FSH surge.
100 mcg · Single one-off dose