Kisspeptin-10
KP-10, Metastin 45-54
The shortest active form of kisspeptin, the brain signal that switches on GnRH and thus LH, FSH and testosterone. Very short-acting; studied only in small research trials.
Legal status: Not approved for any use; sold as a 'research' peptide. Banned in sport for men at all times (WADA S2.2.1, testosterone-stimulating peptides).
What it gives
What people use it for and what the sources report. Strength is a general category from the literature: mild, clear or strong.
Purpose
Used to stimulate natural testosterone production, for example during steroid use or after stopping. In healthy men it raises LH and testosterone in short studies; there are no data on recovery after steroids. Researched for infertility.
What people seek and what studies show
People hope to restart their own testosterone and to support libido and fertility. It acts at the very top of the hormone axis, so it can work only if the pituitary and testes still respond. In small studies of healthy men LH, FSH and testosterone rose quickly, but with constant exposure the LH rise faded within days. In a brain-scan study kisspeptin strengthened responses to sexual and romantic images in young men.
Effects
Evidence: Limited human data — some human studies, small or short
Possible side effects
Possible does not mean certain: whether they appear depends on dose, duration, individual response and monitoring. Below — what to watch for and how to notice it early.
4 possible side effects
level · how often it is reportedWhat the levels mean
Level: general category from the literature, not your personal risk
How often
- common
- reported often
- possible
- reported in some people
- rare
- reported occasionally
How to lower the risks
For 1 of 4 possible side effects there are specific ways to lower the chance: everyday measures, supplements and options a doctor may consider. For the rest — general advice. No measure removes a risk completely.
Products obtained without a prescription are often fake, mislabeled or non-sterile, and there is no way to check at home. For legal supplements, look for third-party testing (Informed Sport, NSF).
What is unknown cannot be lowered, only avoided; tell your doctor what you have taken.
Low-level side effects
How each option helps (2)
- Regular blood tests — LH, FSH and testosterone show how deep suppression is and whether natural production has recovered afterwards.
- Working with a doctor — Assesses how deep suppression is and guides recovery afterwards, including fertility testing.
Check-ups and blood tests
Which tests and check-ups to do and when. This is a guide — agree the exact schedule with your doctor.
Which doctors can help
For women
In women the LH response changes from phase to phase (only about half responded in the early follicular phase), and repeated kisspeptin-54 injections lost their effect within about two weeks.
Myth & fact
“Kisspeptin restarts your testosterone after you stop steroids.”
In short studies it raises LH in healthy men, but it has never been tested for recovery after stopping steroids; prolonged suppression needs a doctor's work-up.
Combinations
No specific combination notes for this substance yet. The stack check still adds up side effects that several substances share.
Sources
Possible side effects by body system, combinations, how to lower the risks and which tests to do — free.
Open the stack check