A protein that starts a hormone chain
What Is Kisspeptin, in everyday words?
Your brain makes this protein, which helps start puberty and guides eggs, sperm, and sex hormones.
What is the short answer about Kisspeptin?
Kisspeptin's main job is to help start your body's sex-hormone chain. Your genes give certain brain cells the instructions for making the protein. Kisspeptin touches a matching place on other nerve cells, which then call on the pituitary gland below your brain. That pea-sized gland sends hormones into the blood. They help guide puberty, periods, egg release, and sperm.
Studies use more than one form. Kisspeptin-54, once called metastin, is longer and stays active longer. Kisspeptin-10 is shorter. Both end with the same final building block, which lets them attach to the right cells. The kisspeptin peptide isn't a sex hormone you can top up, and it isn't a supplement. On this page, I'll show you where the protein comes from and what changed in human tests.
What is the Kisspeptin protein made from?
Kisspeptin belongs to a small family of proteins. One gene carries instructions that tell cells to build kisspeptin. That gene sits on one of your chromosomes, the bundles that hold traits passed down in families. Kisspeptin's main job is to wake certain brain cells [1]. It does so by touching one matching place on their outer wall.
Cells in the brain, placenta, ovaries, testes, and several other tissues make kisspeptin. Its best-known work happens in the brain. It causes short hormone releases with pauses between them, starting a link from brain to gland to sex organs [13]. Kisspeptin isn't a sex hormone. It tells cells higher in the chain to get your own hormones moving.
How does the Kisspeptin peptide get its different forms?
Cells first make a 145-amino-acid protein. That means one hundred forty-five building blocks. Cells cut it into kisspeptin-54 with 54 blocks, or shorter end pieces with 14, 13, or 10. Metastin also means kisspeptin-54. Every form has the same final block, which lets it attach to the right brain cells. Some papers print kisspeptin-10 as a long row of letters. The kisspeptin-10 code only lists the blocks in order; it doesn't show what happens in you.
Researchers most often study kisspeptin-54 and kisspeptin-10. The longer form's lab weight is about 5857 daltons. Scientists use daltons to weigh proteins; here, the larger size helps explain why kisspeptin-54 can act for hours. Kisspeptin-10 leaves blood within minutes [3].
Is a kisspeptin supplement an approved medicine?
No. Despite the search phrase "kisspeptin supplement," kisspeptin is not a dietary supplement; material offered for research remains on sale. The Phase 1 and Phase 2 human trials cited here used kisspeptin under medical supervision; the compound has no FDA, EMA, or other regulatory approval for any indication [7]. It is an investigational reproductive neuropeptide — a research compound studied in trials, not a wellness product. Material described online as research-grade is unregulated, with no guarantee of identity, purity, or concentration, which is a recurring caution in the research-use community.
Prescription access does not settle the compounding question. Kisspeptin is listed by Promise Peptides (mypromise.com) for prescription care; the service now prescribes it when a clinician licensed in the U.S. accepts the case, and that clinician can turn a request down. A patient's state and proposed treatment narrow the choices; the service takes requests only from patients in the United States. Kisspeptin-10 remains a Category 2 substance in FDA's compounding safety list, with significant safety risks; listing it in a catalog is not FDA permission to compound it. The prescription route does not give the compounded drug FDA approval; kisspeptin retains its investigational status without an approved indication.
What changed after people received Kisspeptin?
Kisspeptin tells the brain to start the sex-hormone chain. People born with a faulty receiving part on the right brain cells may not enter puberty. Mice bred with this fault failed to mature too [1]. Those findings show why the contact is needed.
In healthy men, kisspeptin sent through a vein raised two hormones that guide the testes, followed by testosterone [16]. Women who no longer had periods regained short hormone releases with pauses between them [4]. This meant the brain message restarted, not that every woman released an egg. During IVF, kisspeptin helped eggs mature without dangerous ovary swelling in that study [5]. Other work links the brain's kisspeptin timer with body heat and hot flushes after menopause [11]. Doctors are also studying placental kisspeptin in your blood for signs of pregnancy trouble [12].
Where in your body is Kisspeptin made?
Your body makes kisspeptin in several places, but its best-known hormone work happens in the brain. Two groups of brain cells do most of that work. One group sits deep near the middle of the brain. The other lies farther forward. The placenta, ovaries, testes, and other tissues also make the protein [10].
The deep cells keep short hormone releases coming at regular times. The forward cells help cause the large rise that frees an egg from an ovary. During pregnancy, the placenta makes a great deal of kisspeptin. Doctors are studying its blood level for signs that a pregnancy may be in trouble [12]. In most studies here, the name refers to the message that begins in the brain.
Why is Kisspeptin also called metastin?
The older name came from cancer work. In 1996, scientists in Hershey, Pennsylvania, found the body's instructions for kisspeptin while studying melanoma. That skin cancer can spread beyond the skin. The gene seemed to hold back the spread. Its name came from the town's well-known "Kisses" chocolates, while the protein was first called metastin.
After the 2003 puberty findings, scientists began calling the protein kisspeptin and learned about its key sex-hormone role [1]. Metastin and kisspeptin-54 mean the same form. If you see metastin in an older paper, it isn't a different compound. The cancer name came before the hormone name.