Kisspeptin: Reference Overview and Reconstitution Notes

Kisspeptin

What it is

Kisspeptin is a family of neuropeptides encoded by the KISS1 gene that act as endogenous ligands for the receptor GPR54, also called KISS1R. The name covers several length variants that share a common receptor-binding region, including kisspeptin-54, kisspeptin-14, kisspeptin-13, and the shorter synthetic decapeptide kisspeptin-10.

Research context and categorization

Kisspeptin is grouped under the reproductive and neuroendocrine category. It is commonly discussed in relation to the hypothalamic-pituitary-gonadal (HPG) axis, where kisspeptin signaling through GPR54 is described as an upstream activator of gonadotropin-releasing hormone (GnRH) neurons. In the research literature it is investigated for its role in the onset of puberty and in the regulation of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) release. It is also studied in the context of hypothalamic amenorrhea, fertility and reproductive disorders, and, following its original identification as the product of a metastasis-suppressor gene (once called metastin), in tumor biology.

These uses are investigational. Kisspeptin is not FDA-approved for any of them, and any effects reported in study settings are not confirmed or approved benefits.

Status

  • Regulatory status: Research-only and not FDA-approved for any indication. It has appeared in investigational human studies, for example subcutaneous administration in reproductive-disorder and hypothalamic-amenorrhea trials, but no approved kisspeptin product exists. In 2024 an FDA advisory committee reviewed kisspeptin-10 for the 503A compounding bulk-substances list and voted against inclusion, citing limited safety, quality, and efficacy data.
  • Sport status: Prohibited under the WADA Prohibited List. Kisspeptin, its isoforms, and receptor agonists were added as examples under class S2 (Peptide Hormones, Growth Factors, Related Substances and Mimetics), in the testosterone-stimulating peptides grouping applicable to male athletes.

Reconstitution notes (general)

Concentration equals the milligrams in the vial divided by the millilitres of bacteriostatic water added. For example, 10 mg reconstituted with 2 mL yields 5 mg/mL, and 5 mg with 1 mL yields 5 mg/mL, which can then be converted to smaller working units. Bacteriostatic water, which contains about 0.9% benzyl alcohol as a preservative, is generally preferred over plain sterile water for multi-puncture vials because the preservative limits microbial growth once the stopper is broached. A reconstitution calculator is available at our reconstitution and blend calculators.

Dilution and handling notes (compound-specific)

Kisspeptin is supplied as a white lyophilized (freeze-dried) powder for reconstitution. It is generally reported as readily soluble in bacteriostatic water and usually dissolves without the pronounced gelling seen in some peptides. That said, even the short kisspeptin-10 sequence carries a relatively high hydrophobic load (phenylalanine, tryptophan, leucine, and a partly non-polar tyrosine), so at higher concentrations those non-polar surfaces can self-associate and show up as haze, fine particulates, or a gel-like consistency rather than a clear solution. Keeping the working concentration modest, often in the low single-digit mg/mL range with a water volume of roughly 1 mL to 2 mL per vial, reduces that tendency.

Add the diluent slowly by letting it run down the inside of the vial wall rather than spraying it onto the powder, then let the vial sit and dissolve over several minutes with only gentle swirling. Do not shake, since agitation can foam and stress the peptide. If plain bacteriostatic water leaves the solution cloudy or gelled, the commonly cited approach for hydrophobic peptides is to dissolve first in a small volume of dilute acetic acid (on the order of 0.1 to 1 percent) before further dilution, which lowers the pH and discourages aggregation. A second practical point is that kisspeptin, particularly kisspeptin-10, has a short half-life and is often treated as less stable in solution than longer, slowly cleared peptides, so minimizing repeated warming and agitation is sensible. Any solution that stays cloudy or shows persistent particulates should not be treated as fully dissolved.

Handling and storage

Refrigerate reconstituted material at 2 to 8 C and keep it out of light. Wipe the rubber stopper with an alcohol swab before each withdrawal, and label the vial with the date it was mixed. A refrigerated working window of roughly four weeks is a common reference point, and given this compound's shorter stability it is reasonable to err toward the earlier end of that range. Discard the solution if it turns cloudy or discolored or if any floating particles appear.

Related reading

Tools and supplies

For laboratory and research reference only. Educational content, not medical, dosing, injection, or therapeutic guidance, and not intended for human or animal use. Any research uses described are investigational and not confirmed or approved benefits. Confirm anything involving health with a licensed professional. References linked above.