The GIP Pathway
The forgotten incretin: fat metabolism, energy expenditure, and the agonism debate
The Forgotten Incretin
For decades, GIP was dismissed as the "fat-storing hormone" -- the opposite of what you'd want in an obesity drug. Then tirzepatide showed that GIP agonism actually enhances weight loss when combined with GLP-1. This unit unpacks the biology behind this paradox and explains why both retatrutide and tirzepatide include GIP receptor activation as a core mechanism.
GIP Receptor Biology
Tissue distribution, signaling cascades, and the incretin effect.
Fat Metabolism
How GIP receptor activation influences adipocyte biology and energy expenditure.
Agonism vs Antagonism
The scientific controversy: why activating a "fat-storing" receptor helps weight loss.
GIP + GLP-1 Synergy
How dual receptor activation produces more than the sum of its parts.