What we do not know about retatrutide, listed explicitly posts 91–114

Nausea and vomiting were dose-related in the phase 2 work, as they are throughout this class. What is not established is whether the tolerability profile differs from the dual agonists at equipotent effect, because equipotence has not been established either.

I would be interested in a counterexample if anyone has one.

On post #90 — agreed on the reasoning, with one qualification.

Triple agonism: is the effect additive, synergistic, or neither? A phase 2 comparison of tirzepatide (dual) to retatrutide (triple) would answer that question. The published data does not include such a direct comparison.

That holds for the case as described. Change the assumptions and it may not.

Post #92 is right about the mechanism and I think understates the practical bit.

Nausea and vomiting were dose-related in the phase 2 work, as they are throughout this class. What is not established is whether the tolerability profile differs from the dual agonists at equipotent effect, because equipotence has not been established either.

Heart rate increased in a dose-dependent way in the phase 2 work. That is not a footnote — it is one of the specific things phase 3 exists to characterise, and it is why this subcategory is written more cautiously than the others.

This follows post #92 rather than contradicting it.

Anyone deciding on the basis of what is published should know that what is published is a phase 2 programme and some pharmacokinetics. That is a genuinely early evidence base and this page will say so until it changes.

Worth separating two things that post #94 runs together.

Heart rate increased in a dose-dependent way in the phase 2 work. That is not a footnote — it is one of the specific things phase 3 exists to characterise, and it is why this subcategory is written more cautiously than the others.

Nausea and vomiting were dose-related in the phase 2 work, as they are throughout this class. What is not established is whether the tolerability profile differs from the dual agonists at equipotent effect, because equipotence has not been established either.

Retatrutide is investigational. Material obtained outside a clinical trial is research-use-only by definition, is not approved for human use, and carries no assurance about its identity or content beyond whatever independent testing you commission yourself.

That is where I would start, not where I would stop.

Heart rate increased in a dose-dependent way in the phase 2 work. That is not a footnote — it is one of the specific things phase 3 exists to characterise, and it is why this subcategory is written more cautiously than the others.

That is what I would do. It may not be what is correct.

Nausea and vomiting were dose-related in the phase 2 work, as they are throughout this class. What is not established is whether the tolerability profile differs from the dual agonists at equipotent effect, because equipotence has not been established either.

Genuinely open to being wrong about this one.

Heart rate increased in a dose-dependent way in the phase 2 work. That is not a footnote — it is one of the specific things phase 3 exists to characterise, and it is why this subcategory is written more cautiously than the others.

Fair, and the limits you put on it are the part I will remember.

I read post #100 twice before replying, because I had assumed the opposite.

What we do not know about retatrutide, listed explicitly: long-term safety, real-world response rates, the dose response in diverse populations, whether the heart-rate signal persists or attenuates, durability of effect on withdrawal, efficacy in comorbidities beyond obesity.

I have changed my mind on this once already, so take it as current rather than settled.