FERTILITY & HPG-AXIS RESEARCH · DEEP DIVE
Kisspeptin and the HPG Axis
Kisspeptin sits at the very top of the reproductive axis. Discovered as the missing link behind puberty, it switches on the GnRH neurons that set every downstream hormone in motion.
In 60 seconds
Kisspeptin binds a receptor on GnRH neurons in the hypothalamus. GnRH then drives LH and FSH, which drive the gonads. Without the kisspeptin receptor, puberty does not start.
- Kisspeptin switches on GnRH neurons.
- Without its receptor, puberty does not begin.
- It is studied as a physiological IVF trigger.
What it is
A hypothalamic neuropeptide; kisspeptin-10 is its shortest active fragment.
What researchers looked at
GnRH release, LH and FSH responses, puberty genetics and its use as an IVF trigger.
What’s still unknown
Repeated exposure can desensitise the axis in some protocols; it is not an approved medicine.
The gatekeeper of puberty
Researchers found that the kisspeptin receptor (GPR54) is required in mice and in people for the pulsatile release of LH and FSH that starts puberty. A 2005 study showed GPR54 sits on GnRH neurons and that kisspeptin stimulates GnRH release directly — making it the switch upstream of the whole reproductive cascade.
How the axis connects
Kisspeptin → GnRH (hypothalamus) → LH and FSH (pituitary) → testosterone, oestrogen and gamete production (gonads). A 2022 review describes kisspeptin neurons in the arcuate nucleus working alongside neurokinin B and dynorphin to shape the GnRH pulse.
Where it is studied now
Kisspeptin is used as a research tool in reproductive endocrinology, including as an IVF trigger that releases the body’s own LH. Compared with hCG, which acts directly on the gonads, kisspeptin works physiologically from the top of the axis.
The clinical route
If you are trying to conceive or think you may have a hormone problem, the right route is a fertility clinic or an endocrinologist. They test properly (semen analysis, LH, FSH, testosterone, oestradiol) and prescribe registered medicines under monitoring. Nothing here replaces that.
KEY TAKEAWAYS
- Kisspeptin switches on GnRH neurons.
- Without its receptor, puberty does not begin.
- It is studied as a physiological IVF trigger.
Sources · PubMed
- Kisspeptin directly stimulates gonadotropin-releasing hormone release via G protein-coupled receptor 54 · Proc Natl Acad Sci U S A 2005 · PMID 15665093
- The Role of Kisspeptin in the Control of the Hypothalamic-Pituitary-Gonadal Axis and Reproduction · Front Endocrinol (Lausanne) 2022 · PMID 35837314
- Use of kisspeptin to trigger oocyte maturation during in vitro fertilisation (IVF) treatment · Front Endocrinol (Lausanne) 2022 · PMID 36147569
