KisspeptinAlso known as: Metastin, Kiss1, Kisspeptin-54, Kisspeptin-10, Kp-10, Kp-54

Mechanism of Action

Kisspeptin binds to the G protein-coupled receptor GPR54 (also known as Kiss1R) on hypothalamic neurons. This activation stimulates the release of gonadotropin-releasing hormone (GnRH), which in turn triggers the pituitary to release luteinizing hormone (LH) and follicle-stimulating hormone (FSH). These hormones regulate gonadal function, sexual development, and reproductive cycling. Kisspeptin's action is critical for the initiation of puberty and maintenance of fertility.

Reported Research Benefits

Primarily used in preclinical research to study hormonal regulation of fertility, puberty onset, reproductive cycle modulation, and potential therapies for fertility disorders. Also investigated for roles in neuroendocrine signaling and hormonal balance.

Dosing Protocol & Reconstitution

In laboratory research, Kisspeptin is typically reconstituted in bacteriostatic water and administered via subcutaneous injection, often using insulin syringes. Because dosing can vary depending on species and study design, no universal dosage exists, but careful titration and peptide calculator tools are recommended for accurate dosing.

Research Notes

Research shows Kisspeptin has a short half-life in vivo, varying from minutes to about an hour depending on the analog and administration route. Its efficacy in stimulating GnRH release makes it a valuable tool in endocrine studies. Current studies focus on its therapeutic potential for hypogonadism, delayed puberty, and fertility disorders.

Research Summary

Kisspeptin is a neuropeptide encoded by the KISS1 gene that is the master regulator of GnRH pulsatile secretion, LH surges, and the HPG axis. It plays a critical role in puberty initiation, fertility, and reproductive function. Clinical trials demonstrate its ability to stimulate LH and testosterone in hypogonadal men and restore LH pulses in hypothalamic amenorrhea.

Side Effects & Safety

Generally well-tolerated in clinical trials. Nausea, flushing, and mild headache reported in some subjects. Prolonged activation of the HPG axis may cause receptor desensitization. Not recommended during pregnancy or in sex hormone-sensitive conditions.

Stability & Storage

Refer to research notes

Molecular Data

Sequence: YNWNSFGLRF-NH2 (for Kisspeptin-10, the active core fragment)
Molecular Formula: C135H218N42O21
Molecular Weight: 5113.25 g/mol
CAS Number: 546579-97-9
IUPAC Name: L-tyrosyl-L-asparaginyl-L-tryptophyl-L-asparaginyl-L-seryl-L-phenylalanyl-L-glycyl-L-leucyl-L-arginyl-L-phenylalaninamide (Kisspeptin-10)

Primary literature: https://pubmed.ncbi.nlm.nih.gov/?term=Kisspeptin+GnRH+LH+testosterone+fertility