Kisspeptin protocols in the published literature

What amounts of kisspeptin did the published studies use?

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Six sets of figures appear in the research behind this page, and they belong to different molecules, species and units. In the one human study, the receptor agonist MVT-602 was given at 0.01 and 0.03 nmol/kg and native kisspeptin-54 at 9.6 nmol/kg.1 In prepubertal rats, a range of kisspeptin-10 doses was given, listed as 1 μg, 1 ηg and 10 ρg, intraperitoneally twice daily.2 The abstract prints those units with Greek letters, and we read them as one microgram, one nanogram and ten picograms, a range spanning a hundred-thousand-fold. In a rat behaviour study, kisspeptin-10 was given at 3 ng intranasally or 30 ng intraperitoneally.3 In a laboratory study on human ovarian tissue, the exposed group sat in 1 μM kisspeptin.4 The mouse pain work and a rat cell model report amounts less precisely, and they are covered below.

Who received those amounts?

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Almost nobody a reader is likely to resemble. The human amounts went to the follicular phase of healthy women (n = 9), and to women with polycystic ovary syndrome or hypothalamic amenorrhea, six of each.1 That is 21 women in total, each a fertility research subject in the first half of her cycle. The rat behaviour study used 50 copulation naive male Wistar rats divided into 5 groups.3 The pain study gave different doses of kisspeptin-13 to adult male C57BL/6 mice without stating the amounts in its abstract.5 The Leydig-cell rats were 35 days old, which in a rat is before puberty. No man, adolescent or older adult received any of these amounts in a study among the research behind this page. So every figure on this page describes the subjects who received it and no one else, which is the opposite of what a dosage chart pretends to do.

How was kisspeptin administered in the studies?

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Three routes appear, and the route changed what was measured. In the rat behaviour study, kisspeptin-10 given by injection into the abdomen affected both testosterone concentration and sexual motivation.3 Given intranasally, the same peptide did not act on testosterone but increased sexual motivation in those rats.3 So the nose and the abdomen were not two ways of delivering one effect. They produced different results at different amounts, ten times apart. The Leydig-cell rats were injected into the abdomen, which is what intraperitoneally means. The human study's abstract does not state the route at all, and we do not fill that gap from memory. The ovarian tissue was simply bathed in solution. What a person might do with a vial is not a route any of these studies tested.

How often was kisspeptin given, and for how long?

human pilot / early trial

Twice a day in one rat study, and apparently once in most of the others. The Leydig-cell rats were dosed twice daily after every 12 hours, with control rats injected with physiological saline in parallel.2 The abstract does not say how many days the course ran, only that measurements were taken when dosing ended. In the behaviour study, blood samples were collected 30 min after the substance administration, which points to a single dose per animal.3 The human study tracked how long luteinising hormone took to peak, 21.4 hours after the agonist against 4.7 hours after kisspeptin-54.1 A peak timed in hours describes a single exposure, and none of the studies covered here reports a human schedule, a number of days or a course length; the one registered study of sustained administration has not published results.

Is there a kisspeptin dosage chart?

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Not one that can honestly be built from this record. A chart implies a row for each category of person and an amount considered suitable for them, and the published figures cannot populate even one such row. They come from 21 women in a fertility study, rats of two strains and two ages, mice, and tissue in a laboratory dish, expressed in four incompatible units: per kilogram in people, fixed weights in rats, unstated amounts in mice and a concentration in the laboratory. The human study itself was designed to characterize the action of MVT-602 in comparison with native kisspeptin-54, not to find a dose for anyone to use.1 A chart assembled from that material would place numbers from incompatible experiments side by side as though they answered a single question. Any chart circulating online therefore did not originate in the studies covered here, and it represents somebody's editorial choice rather than a research finding.

What does nmol/kg mean, and why does it not translate into a vial?

human pilot / early trial

A nanomole is a count of molecules rather than a weight. Per kilogram means the amount was scaled to each woman's body weight. Counting molecules is how researchers compare two compounds fairly when the molecules differ in size. That is why the human study could set the agonist and kisspeptin-54 side by side in the same unit. Despite the far smaller amount, the agonist's luteinising hormone rise in healthy women was similar in amplitude to that after kisspeptin-54.1 A vial, by contrast, is labelled by weight, in milligrams. Moving between the two needs the exact molecule and its molecular weight, and kisspeptin-10, kisspeptin-13 and kisspeptin-54 are different lengths. The same number of nanomoles of each therefore weighs a different amount. We do not perform that conversion. A per-kilogram figure from a research subject, carried into milligrams for an unlabelled vial, would be a dose recommendation in disguise.

Why is a study amount not a protocol?

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Because each amount was chosen to answer a question about the subjects in that study, and it means nothing outside that frame. The Leydig-cell study was conducted to check the ultrastructure of Leydig cells in prepubertal male rats in response to a range of kisspeptin doses.2 That range was built to look for damage, and it found it. It concluded that chronic intermittent administration of kisspeptin-10 has a dose-dependent degenerative effect in prepubertal male rats.2 An amount picked to find harm in a young rat is not an amount for anyone. The human amounts were picked to compare two molecules over hours. Neither study set out to find what a person should take, and treating either figure as a protocol borrows an authority the study never claimed. That is why no human-equivalent number appears anywhere on this page, which is not the same as hiding one. It is declining to invent one.

Does a lab-dish concentration tell you anything about a dose?

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No, and the difference is worth understanding because lab figures get quoted as doses. In the ovarian tissue study, pieces were divided randomly into two groups, one left alone and one given 1 μM kisspeptin.4 One micromolar is a concentration, meaning how much is dissolved in each litre of the liquid around the tissue. It describes what the cells sat in, rather than what a body would receive. The authors report that maturity genes were expressed during treatment, and they conclude kisspeptin increases the maturity of follicles in that medium.4 A separate rat study used kisspeptin-54 in liver cells to establish a cellular model, without stating the amount in its abstract.6 Both are laboratory set-ups. A concentration that changes gene readings in a dish is not evidence about any amount given to a person.

Is there a cycle or a break in the published work?

registered trial

No cycle appears in the research behind this page, and the reason is pharmacology rather than neglect. A 2022 review says man-made versions of kisspeptin might get round some of the drawbacks that come with the natural forms.7 Among those challenges, covered on the the Kisspeptin overview overview, is a response that fades as dosing continues. That makes on and off schedules a live question with no published answer. The registered study of Reproductive Hormones During Sustained Administration of Kisspeptin is listed as RECRUITING.8 The only once-versus-repeated comparison among these sources ran the other way, switching kisspeptin cells off in mice either once or over two weeks.9 That work silenced the body's own kisspeptin neurons rather than giving any kisspeptin, so it says nothing about a cycle of doses.

What was the starting amount in the studies?

human pilot / early trial

There was none, in the sense people usually mean. No study among the research behind this page started low and stepped up. The rat Leydig study ran three fixed amounts in separate groups, spread across a hundred-thousand-fold range. The human study gave two fixed agonist amounts and one fixed kisspeptin-54 amount, and compared the responses. A starting amount implies a schedule that rises over time, built around how a person tolerates each step, and that design does not appear in this record. The 2020 authors read their clinical and mechanistic data as identifying MVT-602 as having considerable therapeutic potential for female reproductive disorders.1 Therapeutic potential is a statement about the agonist, in women with reproductive disorders. It is not a statement about kisspeptin-10, about men, or about where anyone should begin, so it does not carry over to any of them.

Does an approved dose apply to kisspeptin?

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No kisspeptin product is recorded as approved among the sources behind this page, so there is no labelled amount to report. What exists nearby is approval activity on a neighbouring signal. A 2020 review notes that neurokinin 3 receptor antagonists have shown encouraging preliminary results in postmenopausal cancer-free patients with hot flushes.10 Those drugs block a different receptor in the same brain circuit. Their amounts belong to them, and they say nothing about how much kisspeptin anyone should take. The kisspeptin system also responds to the body's own hormones. In neonatal rats treated with estradiol, the animals had fewer hypothalamic kisspeptin neurons, but the GnRH-LH axis remained responsive to kisspeptin stimulation.11 That shows the response to kisspeptin depends on the state of the system it lands in, which is one more reason a fixed number travels poorly.

How do you reconstitute a kisspeptin vial?

The arithmetic is identical for any freeze-dried peptide, and it requires only the numbers printed on your own vial: concentration equals the stated amount in the vial divided by the volume of liquid added. A vial stated at 5 mg, mixed with 2 mL, holds 2.5 mg in each millilitre, which is 2,500 micrograms per millilitre. The reconstitution calculator at the reconstitution calculator does that division on figures you supply, and it does not suggest an amount. Two cautions apply here that would not apply to a labelled medicine. The stated amount on an unlabelled vial is a claim by whoever filled it, and nothing among the research behind this page checked any such claim. The published amounts above are in nanomoles per kilogram, nanograms or a concentration, and none of them maps onto a count of millilitres from a vial, so the arithmetic can tell you what is in a syringe but not that any study used that amount.