Galanin-like peptide

Where it comes from

Made in

The arcuate nucleus of the hypothalamus and the median eminence; a separate pool sits in the glial cells of the posterior pituitary

Sent out by

Leptin and feeding raise it; fasting lowers it

Acts on

• Feeding circuits
• GnRH neurons
• Thermoregulation

What it does

• Reduces food intake and weight; rats eat more in the first hour before that, mice do not ¹
• Stimulates GnRH and LH release, a link between fuel and fertility
• Raises body temperature as a prostaglandin-driven fever rather than by burning fuel ³

In medicine

• No medicine copies it or blocks it, and it is not measured in people
• It has no human data of any kind: everything known about it comes from rodents and from the pig hypothalamus it was isolated from ¹

Beyond the body’s own use

• Intranasal GALP held weight down in obese mice in one laboratory’s work, alongside less movement; no human trial has been run ²
• Its fever is not a metabolic effect. The rise in temperature runs through interleukin-1 and prostaglandins, and blocking those blocks the fever and the loss of appetite with it, which argues that part of the weight loss is simply feeling unwell ³
• Nothing containing GALP is approved or obtainable outside the laboratory. The open question is whether its appetite effect can be separated from that illness response at all ³