Read the primary source rather than the write-up and the two do not agree, so here is what is actually in it.
Amylin analogues act on a different satiety circuit — area postrema and dorsal raphe — rather than the arcuate pathway GLP-1 agonists use. Because the mechanisms are complementary rather than additive on the same receptor, the combination gets more effect without the tolerability cost of simply pushing GLP-1 higher. REDEFINE-2 put cagrisema near 22.7% against about 15.8% for semaglutide alone.
Where I think it is weakest: the follow-up is short relative to how long people actually take these drugs, so durability is an assumption here rather than a finding.
What I actually want to know is whether the amylin component adds anything beyond what a higher GLP-1 dose would achieve. Practical detail welcome, however dull — the duller the better.
Figures above are from the primary publication rather than the press summary. If a number here disagrees with one you have, post yours and we will work out which of us is reading a secondary source.
Dr.KarenChen said:Amylin analogues act on a different satiety circuit — area postrema and dorsal raphe — rather than the arcuate pathway GLP-1 agonists use.
Agreed, and the adaptation point cuts both ways: tachyphylaxis to gastric emptying is why tolerability improves, and it is also why people who were relying on physical fullness feel the effect fade while the appetite effect is still working.
If somebody has the primary source to hand I would rather cite it than paraphrase it.
Dr.KarenChen said:Amylin analogues act on a different satiety circuit — area postrema and dorsal raphe — rather than the arcuate pathway GLP-1 agonists use.
This is where I part company with the consensus forming above. Two drugs, two side-effect profiles, one price. The efficiency argument only works if the tolerability really is better than dose-escalating a single agent, and I have not seen that demonstrated head to head.
Happy to go further on any of that.
PeptideDetective — Independent Peptide Analytics
Community-driven peptide testing and vendor rating platform. Transparent results. Unbiased analysis. Trusted by thousands.
View ResultsTaking the question as asked, rather than the general version of it. The mechanism is more central than most summaries suggest. Receptor agonism in the arcuate nucleus activates POMC neurons and inhibits AgRP/NPY signalling, and the downstream MC4R pathway is the same one disrupted in monogenic obesity — convergent genetic evidence that the target is the right one. Peripherally there is glucose-dependent insulin secretion, glucagon suppression and delayed gastric emptying, but the gastric component largely adapts over months while the central effect persists, which is why the durable effect is appetite rather than fullness.
pete_manc_UK said:Agreed, and the adaptation point cuts both ways: tachyphylaxis to gastric emptying is why tolerability improves, and it is also why people who were…
Same pattern here, and in the same order. Posting only so the count is not one.