Topic summary

GIP receptor agonism and the argument about direction — does this still hold?

Pharmacology › Receptor biology long read amylin analogues retatrutide Solved

This is a generated summary. It shows the 5 most-liked posts from a topic of 15, in their original order, with the accepted answer included where one exists. It is a reading aid and it will miss nuance — the full topic is the record.

s.cabreraTL223 Jun 2026#3

Building on the opening post rather than restating it.

GIP receptor biology is genuinely contested. Both agonism and antagonism have been argued to produce weight reduction, and the fact that the field can hold both positions tells you how open it is.

17 likes 1mo

PharmNotes_WhitfieldTL4Pharmacist27 Jun 2026#4

bench_notes, post #2: Answering the question the opening post raises rather than the one it answers. Central versus peripheral action: GLP-1 agonism works through both central nervous system effects (appetite) and peripheral effects (gastric motility, insulin). The balance is not fully characterised. Go to post

Amylin signalling reaches satiety through a distinct receptor complex, which is the mechanistic basis for expecting an amylin analogue and an incretin agonist to add rather than overlap.

I am confident about the direction and much less about the magnitude.

32 likes in reply to #2 1mo

b.aaltoTL23 Jul 2026 · edited#6

e.lehtinen, post #5: Narrowing post #4, because the general version has more than one answer. GLP-1 receptor signalling: the GLP-1 receptor is expressed on beta cells (insulin secretion), on neurons (appetite and gastric motility), and on myocardium (contractility). Different tissues respond to the same signal in different ways. Go to post

Everything in post #2 holds. The case it does not cover is the one I have.

Cross-reactivity and selectivity: the compounds are not perfectly selective for their target receptors. Semaglutide has some activity on other receptors; tirzepatide activates both GLP-1 and GIP with different affinities. The off-target effects are part of the overall pharmacology.

The part I am sure of is shorter than the part I have written.

6 likes in reply to #5 25d

k.fonsecaTL2 Solution6 Jul 2026#7

Glucagon receptor agonism raises energy expenditure and promotes hepatic fat oxidation. In a triple agonist the incretin limbs offset the glycaemic consequence, which is why the combination is not self-defeating.

The number is defensible. The precision I gave it is not.

23 likes 22d

IbrahimoviTL2Member20 Jul 2026#12

Building on post #9 rather than restating it.

Biased agonism — where different ligands at the same receptor favour different downstream pathways — is a plausible explanation for differences between compounds in this class and is not a demonstrated one for any specific pair.

27 likes 8d

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