Kisspeptin
Metastin
Kisspeptin is a naturally occurring peptide hormone that plays a crucial role in regulating the hypothalamic-pituitary-gonadal (HPG) axis by stimulating gonadotropin-releasing hormone (GnRH) secretion. This leads to increased luteinising hormone (LH) and follicle-stimulating hormone (FSH) release, which are essential for reproductive function. Originally identified for its tumour-suppressing properties, kisspeptin has since been recognised as a key regulator of puberty onset, fertility, and overall endocrine function.
Beyond its role in reproduction, kisspeptin is involved in modulating sexual behaviour, metabolic balance, and even emotional responses. Research suggests it may have applications in treating hypogonadism, infertility, and even certain sexual dysfunctions. Unlike direct GnRH agonists, which can lead to desensitisation over time, kisspeptin stimulates natural pulsatile GnRH release, making it a promising alternative for hormone regulation.
Protocols
1. Treatment of Hypogonadism & Testosterone Deficiency
Dosage: 100–300 mcg per injection, 3–5 times per week
Cycle: 8–12 weeks, followed by assessment
Administration: Subcutaneous (SC) injection, ideally in the evening to mimic natural GnRH pulses
Stacking: Can be used with Gonadorelin or HCG for enhanced stimulation of testosterone production
Expected Benefits: Increased LH and FSH, improved testosterone levels, enhanced sperm production
2. Fertility Enhancement (Men & Women)
Dosage: 100–200 mcg per injection, 3–5 times per week
Cycle: Continuous use until conception or for 3–6 months
Administration: SC injection, preferably in the evening
Stacking: Can be combined with Clomiphene or HMG for synergistic fertility effects
Expected Benefits: Increased sperm count and motility in men; improved ovulation and menstrual cycle regularity in women
3. Libido & Sexual Function Improvement
Dosage: 100–200 mcg per injection, as needed (1–2 hours before activity)
Cycle: Used on demand or as part of a daily regimen
Administration: SC injection
Stacking: Can be combined with PT-141 (Bremelanotide) for enhanced arousal effects
Expected Benefits: Increased sexual desire, improved erectile function in men, enhanced sensitivity in women
4. Neuroprotective & Metabolic Benefits
Dosage: 100–150 mcg per injection, 3–5 times per week
Cycle: 8–12 weeks, followed by reassessment
Administration: SC injection
Stacking: May be combined with Tesamorelin or Mod GRF (1-29) for metabolic enhancement
Expected Benefits: Potential cognitive improvements, appetite regulation, and metabolic balance
Further reading
Kisspeptin functions by binding to the GPR54 (KISS1R) receptor in the hypothalamus, initiating a cascade that leads to GnRH secretion. This, in turn, stimulates the anterior pituitary gland to release LH and FSH, which are essential for reproductive function in both sexes. Its ability to regulate the HPG axis naturally makes it an attractive candidate for managing hormone-related conditions without the risk of overstimulation seen with direct GnRH analogues.
Clinical studies suggest that kisspeptin administration can significantly increase testosterone levels in men with low natural production, without suppressing endogenous GnRH function. Additionally, it has shown promise in improving ovarian function and menstrual cycle regularity in women with polycystic ovary syndrome (PCOS) and other reproductive disorders.
Beyond reproduction, emerging research indicates that kisspeptin may have roles in modulating mood, anxiety, and metabolic function. Studies have linked it to increased brain activity in regions associated with sexual arousal and reward, suggesting potential applications in treating sexual dysfunctions. Furthermore, kisspeptin's involvement in metabolic regulation raises the possibility of using it in weight management therapies.
While kisspeptin-based treatments are still in experimental stages, ongoing research continues to explore its full therapeutic potential. Its ability to enhance reproductive health without the adverse effects of traditional hormone therapies makes it a compelling candidate for future medical applications.
References
- Dhillo, W. S., et al. (2012). "Kisspeptin-54 stimulates the hypothalamic-pituitary-gonadal axis in human males." The Journal of Clinical Endocrinology & Metabolism, 92(8), 3144–3150.
Jayasena, C. N., et al. (2014). "Subcutaneous kisspeptin-54 infusion elevates serum testosterone in healthy men." Clinical Endocrinology, 81(1), 109–117.
Skorupskaite, K., George, J. T., & Anderson, R. A. (2014). "The kisspeptin-GnRH pathway in human reproductive health and disease." Human Reproduction Update, 20(4), 485–500.
Castellano, J. M., et al. (2006). "Alterations in the hypothalamic kisspeptin/GPR54 system during puberty in male and female rats." Journal of Neuroendocrinology, 18(6), 431–438.
Tena-Sempere, M. (2013). "Kisspeptin signalling in reproductive biology and human disease: Critical advances and remaining challenges." Molecular and Cellular Endocrinology, 381(1-2), 2–9.