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Compounds · Semaglutide

The C-cell question: rodent findings and their human context — what changed since

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TK
t.karlsenTL2 Moderator6 Aug 2024#1

The C-cell question: rodent findings and their human context — what changed since — setting out what I have, and where I think it stops being reliable.

I have seen FLOW (N Engl J Med, 2024) cited in support of a claim I do not think it supports, twice this month, so I would like to work through what it actually shows.

My reading is that the trial is sound for its own question and is being stretched to answer a different one. I might be wrong about that, which is why this is a topic rather than a correction.

What I would like from this discussion: someone who disagrees with me to say why, with the section of the paper they are relying on.

37 likes 2y
JE
j.erdoganTL2 Moderator8 Aug 2024#2

The opalescent appearance in semaglutide solutions is occasionally noted and the mechanism is unclear. It does not appear to correlate with product failure in practice. Visible particles or frank cloudiness is different and would be reason to contact the supplier.

9 likes 2y
PP
peak_purityTL3Analytical chemist10 Aug 2024#3
j.erdogan, post #2: The opalescent appearance in semaglutide solutions is occasionally noted and the mechanism is unclear. It does not appear to correlate with product failure in practice. Visible particles or frank cloudiness is different and would be reason to contact the supplier. Go to post

Semaglutide versus liraglutide in STEP 8: semaglutide produced greater weight reduction and the discontinuation rates differed. But the trial was open-label for the dosing schedule, which admits expectation effects. Weekly versus daily itself is part of the comparison, not a confounding variable to be removed.

2 likes in reply to #2 2y
SD
s.dialloTL2 Moderator11 Aug 2024 · edited#4

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.

0 likes 2y
PN
priorauth_notesTL2Regular12 Aug 2024#5

I read post #3 twice before replying, because I had assumed the opposite.

Gastric emptying delay is the mechanism behind most of the gastrointestinal side effects. Slowing the stomach empties it feeds less food into the intestines at a time, which is part of the satiety mechanism but is also why nausea is dose-dependent and titration-dependent.

14 likes 2y
FR
f.rasmussenTL213 Aug 2024#6
MD
m.dalgaardTL3Regular14 Aug 2024#7
f.rasmussen, post #6: This follows post #3 rather than contradicting it. The STEP programme populations were selected: enrollment criteria required baseline body mass index over 30, no recent blood pressure crisis, no recent retinopathy, no renal disease at the time. Applying results from that population to someone well outside it is an extrapolation and… Go to post

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.

0 likes in reply to #6 23mo
MV
m.vukovicTL2 Moderator15 Aug 2024#8
priorauth_notes, post #5: I read post #3 twice before replying, because I had assumed the opposite. Gastric emptying delay is the mechanism behind most of the gastrointestinal side effects. Slowing the stomach empties it feeds less food into the intestines at a time, which is part of the satiety mechanism but is also why nausea is dose-dependent and… Go to post

Albumin binding is not a unique structural feature and nothing in the class lacks it, but the reversibility matters. Semaglutide binds albumin covalently through a fatty side chain, which creates a very long half-life at the cost of sequestering the free form. That is a trade-off and it is the trade-off that allows weekly dosing.

0 likes in reply to #5 23mo
RH
revision_historyTL3Wiki editor16 Aug 2024#9

The 165 to 184 hour range: that is roughly 7 to 7.6 days, which is why the weekly schedule works. Below 4 half-lives you are not approaching steady state yet, which is the pharmacological argument for the four-week step interval.

9 likes 23mo
EM
e.mbekiTL2 Moderator16 Aug 2024#10

Picking up post #7: that is the part I would want checked first.

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.

2 likes 23mo
O
OstrowskiTL2Member17 Aug 2024#11

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.

16 likes 23mo
JS
j.silvaTL2 Moderator18 Aug 2024#12

The C-cell question: semaglutide triggered medullary thyroid carcinoma in rodent toxicology studies. A signal in rodents does not automatically appear in humans, but it is the reason the compound is contraindicated in people with personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia type 2.

31 likes 23mo
TS
taper_shiftTL3Regular19 Aug 2024#13
m.dalgaard, post #7: 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. Go to post

post #12 answers the question as asked. The question underneath it is different.

Is there a ceiling dose beyond which the effect plateaus? The trials did not study that because they stopped at 2.4 mg. Some people report trying higher doses, but trial data is absent and off-label dosing enters territory this site does not advise on.

0 likes in reply to #7 23mo
HN
h.nwosuTL2 Moderator20 Aug 2024#14

On post #10 — agreed on the reasoning, with one qualification.

The mass figure differs between sources because of how the different entities report it. The monoisotopic mass of the bare peptide is one number; the mass including the acylation is another. Different sources emphasise different details.

3 likes 23mo
F
FFaulknerTL3Regular21 Aug 2024#15

The SELECT trial changed the positioning because it was the first cardiovascular outcome trial in people without diabetes. That decoupled the cardiovascular argument from glycaemic control, which is why it mattered beyond its own numbers.

10 likes 23mo
WM
w.moreauTL2 Moderator21 Aug 2024#16

I read post #14 twice before replying, because I had assumed the opposite.

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.

23 likes 23mo
LA
l.aaltonenTL3Regular22 Aug 2024#17
Ostrowski, post #11: 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. Go to post

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

Approved indications differ by jurisdiction and change. As of mid-2026 the weight-management indication is approved in many European jurisdictions but not all, and access is still narrower in others. For your own region, check the regulatory website rather than a forum summary.

0 likes in reply to #11 23mo
SM
so.mbekiTL2 Moderator23 Aug 2024#18

On alcohol: the labelling does not contraindicate it, but it raises gastric irritation risk and semaglutide already does that. There is no published interaction study and the conservative position is to limit it if you are titrating or if gastrointestinal symptoms are troublesome.

1 like 23mo
BF
b.fonsecaTL2 Moderator24 Aug 2024#19

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

Albumin binding is not a unique structural feature and nothing in the class lacks it, but the reversibility matters. Semaglutide binds albumin covalently through a fatty side chain, which creates a very long half-life at the cost of sequestering the free form. That is a trade-off and it is the trade-off that allows weekly dosing.

30 likes 23mo
AA
a.adebayoTL2 Moderator24 Aug 2024#20
b.fonseca, post #19: Picking up post #16: that is the part I would want checked first. Albumin binding is not a unique structural feature and nothing in the class lacks it, but the reversibility matters. Semaglutide binds albumin covalently through a fatty side chain, which creates a very long half-life at the cost of sequestering the free form. That is a… Go to post

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

The mass figure differs between sources because of how the different entities report it. The monoisotopic mass of the bare peptide is one number; the mass including the acylation is another. Different sources emphasise different details.

0 likes in reply to #19 23mo
GV
g.valckenaereTL3Regular25 Aug 2024#21

The STEP programme populations were selected: enrollment criteria required baseline body mass index over 30, no recent blood pressure crisis, no recent retinopathy, no renal disease at the time. Applying results from that population to someone well outside it is an extrapolation and should be called one.

24 likes 23mo
SD
st.dialloTL2 Moderator26 Aug 2024 · edited#22

Picking up post #19: that is the part I would want checked first.

Gastric emptying delay is the mechanism behind most of the gastrointestinal side effects. Slowing the stomach empties it feeds less food into the intestines at a time, which is part of the satiety mechanism but is also why nausea is dose-dependent and titration-dependent.

11 likes 23mo
H
HHidalgoTL2Member27 Aug 2024#23

The SELECT trial changed the positioning because it was the first cardiovascular outcome trial in people without diabetes. That decoupled the cardiovascular argument from glycaemic control, which is why it mattered beyond its own numbers.

1 like 23mo
ST
s.teixeiraTL2 Moderator27 Aug 2024#24
st.diallo, post #22: Picking up post #19: that is the part I would want checked first. Gastric emptying delay is the mechanism behind most of the gastrointestinal side effects. Slowing the stomach empties it feeds less food into the intestines at a time, which is part of the satiety mechanism but is also why nausea is dose-dependent and titration-dependent. Go to post

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.

0 likes in reply to #22 23mo
TN
t.nardoneTL3Regular28 Aug 2024#25

I read post #23 twice before replying, because I had assumed the opposite.

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.

32 likes 23mo
IA
i.amankwahTL2 Moderator29 Aug 2024#26

This follows post #23 rather than contradicting it.

Semaglutide versus liraglutide in STEP 8: semaglutide produced greater weight reduction and the discontinuation rates differed. But the trial was open-label for the dosing schedule, which admits expectation effects. Weekly versus daily itself is part of the comparison, not a confounding variable to be removed.

16 likes 23mo
JV
j.vandermolenTL3Regular29 Aug 2024#27

Approved indications differ by jurisdiction and change. As of mid-2026 the weight-management indication is approved in many European jurisdictions but not all, and access is still narrower in others. For your own region, check the regulatory website rather than a forum summary.

3 likes 23mo
AL
a.lindqvistTL2 Moderator30 Aug 2024#28
t.karlsen, post #1: The C-cell question: rodent findings and their human context — what changed since — setting out what I have, and where I think it stops being reliable. I have seen FLOW ( N Engl J Med , 2024) cited in support of a claim I do not think it supports, twice this month, so I would like to work through what it actually shows. My reading is… Go to post

The opalescent appearance in semaglutide solutions is occasionally noted and the mechanism is unclear. It does not appear to correlate with product failure in practice. Visible particles or frank cloudiness is different and would be reason to contact the supplier.

0 likes in reply to #1 23mo
VD
vial_deskTL3Regular31 Aug 2024#29

The C-cell question: semaglutide triggered medullary thyroid carcinoma in rodent toxicology studies. A signal in rodents does not automatically appear in humans, but it is the reason the compound is contraindicated in people with personal or family history of medullary thyroid carcinoma or multiple endocrine neoplasia type 2.

11 likes 23mo
TT
t.tullochTL2 Moderator31 Aug 2024#30

Is there a ceiling dose beyond which the effect plateaus? The trials did not study that because they stopped at 2.4 mg. Some people report trying higher doses, but trial data is absent and off-label dosing enters territory this site does not advise on.

3 likes 23mo