Triple agonism: additive, synergistic, or neither?

Picking up post #12: that is the part I would want checked first.

Glucagon receptor agonism seems paradoxical in a weight-loss compound because glucagon raises blood glucose. The paradox resolves because glucagon agonism also increases energy expenditure and promotes hepatic fat oxidation, and the incretin components offset the glycaemic effect. In diabetes trials, HbA1c improved rather than worsened.

Practical note that does not fit anywhere else. Whatever you conclude from this topic, write down what you did and when. The single most useful thing in your own records is not any individual result; it is that they are dated and consecutive.

TRIUMPH is phase 3 and it is ongoing. No phase 3 results exist. Nothing should be attributed to TRIUMPH because the trial has not finished. When it does, this page will update.

Glucagon receptor agonism seems paradoxical in a weight-loss compound because glucagon raises blood glucose. The paradox resolves because glucagon agonism also increases energy expenditure and promotes hepatic fat oxidation, and the incretin components offset the glycaemic effect. In diabetes trials, HbA1c improved rather than worsened.

This follows post #16 rather than contradicting it.

Hepatic effects: glucagon receptor agonism promotes hepatic fat oxidation, which is mechanistically plausible for benefit in metabolic liver disease. Whether that translates to improved clinical outcomes is being tested in phase 2 work.

I read post #18 twice before replying, because I had assumed the opposite.

How to read phase 2 without treating it as phase 3: phase 2 establishes that a dose range produces an effect and is tolerable enough to justify large trials. It does not establish safety, durability, or whether real humans differ from the selected population.

I read post #19 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.

The phase 2 obesity paper reported dose-dependent weight reduction of a magnitude that attracted attention. It also reported dose-dependent heart-rate increases. The heart-rate signal is the reason phase 3 exists rather than something assumed negligible based on phase 2.

TRIUMPH is phase 3 and it is ongoing. No phase 3 results exist. Nothing should be attributed to TRIUMPH because the trial has not finished. When it does, this page will update.

post #23 is right about the mechanism and I think understates the practical bit.

Thank you for the correction. I have edited my earlier post with a note rather than silently, so the thread still makes sense to read. The error was mine and it was the kind that comes from remembering a figure instead of looking it up.

Coming back to post #23, because the follow-up matters more than the original answer.

Dose escalation in the published trials: the protocols started at lower doses and escalated by defined steps. The step sizes are documented and they may or may not match what someone self-prescribing would choose.

Picking up post #23: that is the part I would want checked first.

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.

Why this subcategory is more cautious than elsewhere: retatrutide is investigational, phase 3 is ongoing, and the heart-rate signal in phase 2 is not negligible. Caution is proportionate to the evidence status.

Mass and identity: a report on retatrutide should state the mass detected by LC-MS, not assume a theoretical mass. The theoretical mass is not published in peer-reviewed literature for retatrutide at present.

This follows post #27 rather than contradicting it.

Phase 2 sample sizes are not adequate for safety characterisation of a novel triple agonist. Phase 3 is where that question gets answered. Using phase 2 results to make claims about safety profile is using the trial for a purpose it was not designed for.