Compounds · Retatrutide

How to read a phase 2 result without treating it as a phase 3 result

Compounds › Retatrutide randomised trial preprint effect size TRIUMPH programme

e.krastevTL24 Nov 2025#1

The question in the title: How to read a phase 2 result without treating it as a phase 3 result I will give what I have already checked below so nobody repeats it.

Putting the numbers in the first post, because a question about a compound without them turns into a question about somebody's impression of it.

retatrutide, monoisotopic mass near 4731.3 Da, 4 weeks of my own notes, and 4 lots from 2 suppliers with a purity figure on each. That is the whole basis of what follows.

What I want checked is the reasoning I have built on top of it, not the figures themselves.

44 likes 9mo

taper_tableTL3Regular8 Nov 2025#2

The arithmetic in the opening post is right; the assumption feeding it is the part to check.

Renal and cardiovascular outcome data does not exist for this compound. Absence of a reported signal in a phase 2 trial of a few hundred people is not evidence of absence.

A guess, clearly labelled as one.

11 likes 9mo

t.verhoevenTL210 Nov 2025#3

taper_table, post #2: The arithmetic in the opening post is right; the assumption feeding it is the part to check. Renal and cardiovascular outcome data does not exist for this compound. Absence of a reported signal in a phase 2 trial of a few hundred people is not evidence of absence. A guess, clearly labelled as one. Go to post

The evidence status here should be stated in the first line of any post about it rather than the last. Everything is phase 2 or earlier, and a reader arriving from a search will not know that unless somebody says so.

I would not lead a decision with this, but I would not ignore it either.

3 likes in reply to #2 9mo

l.chevalierTL3Regular12 Nov 2025#4

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.

Adding it in case it saves somebody the afternoon it cost me.

0 likes in reply to #2 8mo

k.haddadTL214 Nov 2025 · edited#5

The phase 3 programme is ongoing and its results will change what can be said here. Until then, this subcategory's convention is to state the phase alongside any result quoted.

17 likes 8mo

c.niemelTL3Regular16 Nov 2025#6

Adding the measurement that post #3 says would settle it.

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.

7 likes 8mo

r.mwangiTL218 Nov 2025#7

I had written a reply contradicting post #3 and deleted it. Here is what survived.

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.

I would hold that lightly until someone with a larger sample weighs in.

1 like 8mo

excursion_checkTL3Regular20 Nov 2025#8

l.chevalier, post #4: 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. Adding it in case it saves somebody the afternoon it cost me. Go to post

Thank you for the correction. I would rather find out here than later.

0 likes in reply to #4 8mo

d.barrosTL221 Nov 2025#9

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.

Correct me on the arithmetic if it is wrong; I would rather know.

12 likes 8mo

m.ivaturiTL223 Nov 2025#10

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 call that likely rather than established.

4 likes 8mo

r.serranoTL225 Nov 2025#11

Discontinuation for adverse effects in phase 2 was not negligible at the higher doses. That figure belongs next to the efficacy figure whenever the efficacy figure is quoted.

The general case is well covered; this is the awkward specific one.

0 likes 8mo

peak_purityTL3Analytical chemist26 Nov 2025#12

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.

2 likes 8mo

m.onwukaTL228 Nov 2025#13

k.haddad, post #5: The phase 3 programme is ongoing and its results will change what can be said here. Until then, this subcategory's convention is to state the phase alongside any result quoted. Go to post

Adding the measurement that post #12 says would settle 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.

8 likes in reply to #5 8mo

owen.bradyTL4 Moderator29 Nov 2025#14

Post #10 describes the usual case. This is about the unusual one.

None of the above is medical advice and I am not qualified to give any.

18 likes 8mo

g.rasmussenTL21 Dec 2025 · edited#15

I will take the caveat as seriously as the claim, which is the point of putting it there.

0 likes 8mo

mira.patelTL4 Admin2 Dec 2025 · edited#16

I had written a reply contradicting post #14 and deleted it. Here is what survived.

On identity confirmation more generally: for a compound with no widely available reference material, orthogonal confirmation matters more than usual. A mass result and a chromatographic result together say considerably more than either alone.

0 likes 8mo

b.demirTL24 Dec 2025#17

excursion_check, post #8: Thank you for the correction. I would rather find out here than later. Go to post

Picking up post #16: that is the part I would want checked first.

If the premise is wrong, everything after it is decoration.

4 likes in reply to #8 8mo

s.bruunTL25 Dec 2025#18

peak_purity, post #12: 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. Go to post

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.

The claim is narrower than it sounds, and deliberately so.

13 likes in reply to #12 8mo

m.kjaerTL27 Dec 2025#19

Post #16 is right about the mechanism and I think understates the practical bit.

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.

Adding it because I spent an afternoon working it out and nobody should have to twice.

1 like 8mo

microgramsTL2Regular8 Dec 2025#20

mira.patel, post #16: I had written a reply contradicting post #14 and deleted it. Here is what survived. On identity confirmation more generally: for a compound with no widely available reference material, orthogonal confirmation matters more than usual. A mass result and a chromatographic result together say considerably more than either alone. Go to post

Coming back to post #18, because the follow-up matters more than the original answer.

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.

For what it is worth, the same held on the two occasions I checked.

7 likes in reply to #16 8mo

n.torrenceTL3Regular9 Dec 2025#21

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 would put a moderate confidence on that and no more.

0 likes in reply to #2 8mo

mi.almeidaTL211 Dec 2025#22

Whether triple agonism is additive or synergistic is an open question and the published work does not answer it. A phase 2 trial without a dual-agonist comparator arm cannot distinguish the two.

I checked the source rather than the summary, and they differ.

0 likes 8mo

s.poulsenTL3Regular12 Dec 2025#23

This settles it for me, at least until somebody posts a reason it should not.

13 likes 8mo

a.petrovTL213 Dec 2025#24

Dose-response in the phase 2 obesity work was clear across the studied range, with no obvious plateau within it. Extrapolating beyond the highest studied dose from that is exactly the reasoning trials are designed to prevent.

4 likes 7mo

KnowltonTL3Regular15 Dec 2025#25

The phase 2 obesity data is genuinely striking and it is phase 2 data. Sample sizes at that stage characterise a dose-response relationship; they do not characterise a safety profile, and treating them as though they did is the error to avoid here.

That is what the documentation says. What happens in practice is usually close.

2 likes in reply to #4 7mo

s.achebeTL216 Dec 2025#26

a.petrov, post #24: Dose-response in the phase 2 obesity work was clear across the studied range, with no obvious plateau within it. Extrapolating beyond the highest studied dose from that is exactly the reasoning trials are designed to prevent. Go to post

Post #24 is right about the mechanism and I think understates the practical bit.

The phase 3 programme is ongoing and its results will change what can be said here. Until then, this subcategory's convention is to state the phase alongside any result quoted.

Marking that as an opinion rather than a finding.

0 likes in reply to #24 7mo

VThorvaldsenTL317 Dec 2025#27

Collapsed as off-topic by two members at trust level 3 or above

Whether triple agonism is additive or synergistic is an open question and the published work does not answer it. A phase 2 trial without a dual-agonist comparator arm cannot distinguish the two.

k.agyemanTL219 Dec 2025#28

The reasoning is more useful than the number, which is why I have shown it.

8 likes 7mo

p.amankwahTL220 Dec 2025#29

Post #28 put the caveat in the right place and I want to underline it.

0 likes 7mo

i.coelhoTL221 Dec 2025#30

20 likes 7mo

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