Kisspeptin

Where it comes from

Made in

Neurons of the hypothalamus, in the infundibular and preoptic areas; and the placenta in pregnancy, when blood levels rise thousands of times

Sent out by

Pulses that quicken at puberty and a surge before ovulation; oestrogen and leptin act upstream of it

Acts on

• GnRH neurons of the hypothalamus

What it does

• Drives GnRH, and through it LH and FSH from the pituitary
• People born with a receptor that cannot signal do not go through puberty ¹
• Triggers the LH surge that releases the egg

In medicine

• Used to trigger egg maturation in IVF: in a phase 2 trial of 60 women at high risk, 95 per cent matured eggs and none developed moderate, severe or critical ovarian hyperstimulation ²
• Tested for low sexual desire ³ and for the hormonal silence of hypothalamic amenorrhoea
• No kisspeptin is an approved medicine anywhere

Beyond the body’s own use

• A single dose shows whether the pituitary can still answer, so it is studied as a test to tell a delayed puberty from a permanent failure of the axis
• Crossover trials of a 75-minute infusion, in 32 women with low sexual desire ³ and in 32 men with the same complaint ⁴, changed activity in the brain’s sexual circuits; in the men penile tumescence rose by up to 56 per cent over placebo
• The placenta makes kisspeptin in quantity, and the level in early pregnancy is studied as a marker of miscarriage risk and of pre-eclampsia; neither has reached care