Retatrutide dose escalation in the published trials posts 121–150
This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1.
This follows post #119 rather than contradicting it.
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.
Worth separating two things that post #119 runs together.
Retatrutide is investigational. Anything obtained outside a trial is by definition research-use-only material with no human-use authorisation. This site will state that plainly rather than winking at it.
Coming back to post #123, because the follow-up matters more than the original answer.
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.
Picking up post #123: that is the part I would want checked first.
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.
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.
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 read post #127 twice before replying, because I had assumed the opposite.
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.
For anyone arriving from a search: the marked solution above is the direct answer, and the replies underneath it add the caveats that make it safe to use.
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.
Picking up post #130: 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.
Coming back to post #132, because the follow-up matters more than the original answer.
Two things before anyone answers the substance.
First, the context in the first post is clear and specific. Second, the question is framed so that an answer can actually address it. Both are the norm here and both matter more than they sound.
Collapsed as off-topic by two members at trust level 3 or above
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.
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.
For anyone arriving from a search: the marked solution above is the direct answer, and the replies underneath it add the caveats that make it safe to use.
I read post #136 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.
Retatrutide is investigational. Anything obtained outside a trial is by definition research-use-only material with no human-use authorisation. This site will state that plainly rather than winking at it.
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.
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.
Coming back to post #141, 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 #141: 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.
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.
I read post #145 twice before replying, because I had assumed the opposite.
Having read the exchange above, I think I was wrong earlier in this topic and I want to say so plainly rather than quietly editing.
The correction was fair and I had been repeating something I had not checked carefully enough.
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.
On post #145 — agreed on the reasoning, with one qualification.
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.
post #149 answers the question as asked. The question underneath it is different.
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.