Vol. 3, No. 6 — June 2026Independent since 2024

TheCompound Journal

Reporting on incretins, compounding & the peptide supply chain

A monthly journal of record.
30 issues · 32 contributors
Not medical advice. We sell nothing.

Every letter we have printed

Page 56 of 77 of this archive, newest first.

Page 56 of 77 · back to the first page · 3,055 letters in total

On “The advice is mostly reasonable. The certainty is not earned.” — Patient Notes, 22 Sep 2024

You write that no trial has measured strength. There are observational cohorts with grip strength data. Why do you insist on randomised measurement?

D. Mazzarella, Catania

The Journal replies

Because grip strength in an observational cohort of people who chose to take a drug, and who differ from those who did not in age, motivation and comorbidity, cannot separate the drug effect from the selection. We report those cohorts and we do not treat them as answering the question.

On “The advice is mostly reasonable. The certainty is not earned.” — Patient Notes, 22 Sep 2024

As a DXA technologist of twenty-two years I would add one thing to your precision section: the largest source of error in practice is not the machine, it is positioning. A patient scanned with their arms two centimetres further from their trunk will report different regional values. We are trained to a protocol and the protocol is not always followed.

A. Mbeki, Lusaka

The Journal replies

We should have said this and did not. It also argues for what you presumably practise: same device, same technologist, same protocol, and a note in the record when any of those changes.

On “The advice is mostly reasonable. The certainty is not earned.” — Patient Notes, 22 Sep 2024

I train four times a week, eat a hundred and sixty grams of protein and my appendicular lean mass has fallen by 1.8 kg over ten months while every lift has gone up. Your section on mass against function was the first thing I have read that made that seem normal rather than a failure.

C. Adeoti, Ibadan

On “Stepping down against stopping: two decisions treated as one” — Clinical Trials, 21 Sep 2024

The claim that stopping does not leave you worse off than baseline is a group-level claim about trial arms. Individuals can and do overshoot. Your phrasing invites readers to conclude otherwise.

S. Lindgren, Uppsala

The Journal replies

Correct, and the distinction matters. We have added a clause: no arm overshot at a group level, which is not the same as no participant overshooting. The trials do not report individual overshoot rates and we have not found them published anywhere.

On “Stepping down against stopping: two decisions treated as one” — Clinical Trials, 21 Sep 2024

I take this for kidney disease, not for weight. Every piece of writing I encounter about stopping is about the weight coming back. It has taken me a year to find anybody willing to say plainly that the renal benefit accrued over years of treatment and nobody has tested what happens if I stop.

T. Brannon, Boise, ID

On “What STEP 4 and SURMOUNT-4 actually established” — Pharmacology, 20 Sep 2024

Your piece treats the four-week step as arithmetic, and I accept the arithmetic, but my prescriber moved me up every two weeks and I reached the top dose without difficulty. I do not think the schedule is as constraining as you suggest.

T. Blakemore, Hull

The Journal replies

Nor do we, and the file should have been clearer. The four-week interval is a floor below which the previous rung is still accumulating, not a threshold below which escalation is unsafe. Plenty of people tolerate faster ascent. Our objection is to the inverse inference — that because you did, everybody should — and to the absence of a trial that would let anyone say which is which in advance.

On “What STEP 4 and SURMOUNT-4 actually established” — Pharmacology, 20 Sep 2024

You keep insisting on peptide content rather than purity when discussing dose certainty. I have looked at a dozen certificates from four different testing services and content is reported on perhaps a third of them. What are readers supposed to do with an absence?

M. Guðmundsdóttir, Reykjavík

The Journal replies

Treat the nominal figure as an upper bound and say so out loud when reasoning about a dose. It is an unsatisfying answer and it is the honest one. We have argued in Analytics that content should be a standard reported field, and we will keep naming the services that report it and those that do not.

On “Do you need the top of the ladder?” — Pharmacology, 20 Sep 2024

Your residual-exposure table gives six per cent after four weeks. I calculate 6.25 per cent, which is a quibble, but the larger point is that it assumes steady state at the moment of interruption. Someone who stops three weeks into a new rung has less on board than your table implies.

O. Brannigan, Galway

The Journal replies

Correct on both counts, and the table now carries the steady-state assumption explicitly. Your second point is the more useful one: interrupting mid-escalation clears faster than interrupting from a settled dose, and the practical reading of the table should be adjusted accordingly.

On “Do you need the top of the ladder?” — Pharmacology, 20 Sep 2024

As a prescribing pharmacist I would add one thing about re-titration. The commonest problem I see is not the resumption dose. It is that the patient has a pen left over at the old strength and uses it because it is in the fridge and it cost money. The clinical decision and the economic decision are not the same decision.

G. Papadakis, Thessaloniki

The Journal replies

Well put, and we had not written it down. The cost of discarding partially used material is a real input into dosing behaviour in a market where much of the spend is out of pocket, and it deserves treatment in The Ledger rather than a sentence here.

On “Do you need the top of the ladder?” — Pharmacology, 20 Sep 2024

You describe the plateau as an energy-balance event and dismiss receptor desensitisation. Is there not a third possibility — that adherence quietly falls off at around a year and the plateau is partly a behavioural artefact of the trial rather than a physiological one?

N. Fairweather, Hamilton

The Journal replies

There is, and it is a better objection than the desensitisation argument. Adherence does decline over the second year of the long programmes, and the treatment-policy analyses absorb that decline into the mean. We should have said that the plateau is very likely a composite of energy balance and falling adherence, in proportions the published analyses do not separate cleanly.

On “Do you need the top of the ladder?” — Pharmacology, 20 Sep 2024

The claim that nobody has randomised escalation intervals is too strong. There are protocol amendments in several programmes that effectively created slower-titration cohorts, and some of those have been analysed post hoc.

M. Karlsen, Kristiansand

The Journal replies

Post-hoc comparison of cohorts created by amendment is not randomisation, and treating it as such is exactly the elision we were objecting to. We accept that such analyses exist and are informative; we maintain that they cannot settle the question, and the file now says so in those terms.

On “What the trials monitored, and what that implies about routine practice” — Laboratory Notebook, 19 Sep 2024

My eGFR has risen from 71 to 84 over fourteen months of treatment and I have lost twenty-six kilograms. My prescriber described this as the drug protecting my kidneys. Having read your creatinine section, I suspect it is mostly that I have less muscle. Which of us is right?

B. Sundqvist, Turku

The Journal replies

On the information given, probably you, at least in part. A rise of that size during weight loss of that magnitude is well within what reduced creatinine production can produce. A cystatin C-based estimate alongside the creatinine one would separate the two, and is the measurement worth asking for. It is also possible both things are happening.

On “What the trials monitored, and what that implies about routine practice” — Laboratory Notebook, 19 Sep 2024

I stopped treatment fifteen weeks ago and my panel is worse than I expected. I had a panel at five weeks that looked fine and I had assumed I had escaped. Your point about the twelve-week timing was the explanation nobody offered me.

H. Fitzmaurice, Preston

On “What the trials monitored, and what that implies about routine practice” — Laboratory Notebook, 19 Sep 2024

As a biomedical scientist I would add one point to your reference-interval section: many laboratories do not derive their own intervals at all. They adopt the manufacturer interval for the platform, which was established in a population that may have nothing to do with the one being tested. The interval on the report can be a document about a different country.

E. Marchbank, Perth, WA

The Journal replies

This is correct, common, and something we should have stated. We have added it, and it strengthens rather than weakens the argument for within-person comparison.

On “What the trials monitored, and what that implies about routine practice” — Laboratory Notebook, 19 Sep 2024

You give the reference change value for ALT as about sixty per cent, which strikes me as so large as to make routine monitoring of it pointless. Is that your position?

J. Prendergast, Wollongong, NSW

The Journal replies

Not quite. It makes monitoring for small movements pointless, which is different. A doubling is well outside the RCV and is a real signal; a rise from 28 to 41 is not. The value of the test lies in detecting the former, and much of the anxiety it generates comes from acting on the latter.

On “Where the receptor is: a tissue-by-tissue account of tirzepatide’s reach” — Explainers, 19 Sep 2024

You describe biased agonism as "legitimate and probably important" and then decline to say which molecules are biased in which direction. That is a strange place to stop.

P. Ekundayo, Akure

The Journal replies

It is, and it is deliberate. The published bias factors for these ligands are measured in different systems and are not comparable to one another. We would rather stop than publish a ranking that the underlying assays cannot support.

On “Where the receptor is: a tissue-by-tissue account of tirzepatide’s reach” — Explainers, 19 Sep 2024

I found the section on the area postrema genuinely clarifying. I had assumed nausea was a stomach problem and had been treating it as one, unsuccessfully, for four months.

J. Wenninger, Graz

On “Where the receptor is: a tissue-by-tissue account of tirzepatide’s reach” — Explainers, 19 Sep 2024

I have been on treatment for fourteen months and stopped losing weight at month eleven. Your piece says this is energy balance rather than receptor desensitisation. I would find that easier to accept if anybody had explained it to me at the start rather than after I had spent two months assuming the drug had stopped working.

A. Fournier, Nantes

The Journal replies

That is a fair criticism of the field rather than of this article, and we take the point about timing. The plateau is predictable and predicted; it is very rarely mentioned before it happens.

On “Where the receptor is: a tissue-by-tissue account of tirzepatide’s reach” — Explainers, 19 Sep 2024

A small thing: you write "class B GPCR" and then "secretin-like receptor" as though these were different classifications. They are the same family under two naming conventions, and the piece would be clearer if it said so.

L. Fontaine, Brussels

The Journal replies

Fair, and now stated in the text.

On “Where the receptor is: a tissue-by-tissue account of tirzepatide’s reach” — Explainers, 19 Sep 2024

Your piece states that moving the injection day does not change total exposure, and I accept the arithmetic, but I want to record that it changed my experience considerably. I moved from Monday morning to Thursday evening and the two worst days now fall on a weekend. The drug is doing the same thing; my week is not.

F. Duquesne, Lyon

The Journal replies

This is exactly the distinction we were trying to draw and evidently drew badly. Total exposure is unchanged; the phase relationship between peak concentration and your working week is not. We have added a sentence to that effect.

On “Freezing a reconstituted vial: the ice-water interface problem” — Analytics, 17 Sep 2024

You draw a distinction between retest date and expiry date and then say suppliers use the wrong word. Which word do you think they should use, given that most of them have no study behind either?

C. Nightingale, Plymouth

The Journal replies

Retest, with a stated interval and a note that no formal stability study supports it. That is an honest description of a chemical supplier’s position and it is standard practice in the wider chemical trade. Printing expiry implies a study exists, which is the specific inference we object to.

On “Freezing a reconstituted vial: the ice-water interface problem” — Analytics, 17 Sep 2024

I would add one omission to your list. Nobody states the headspace gas. Nitrogen-backfilled vials and air-sealed vials behave differently for any oxidation-prone sequence, and it is a single word on a certificate.

J. Kettleborough, Nottingham

On “Freezing a reconstituted vial: the ice-water interface problem” — Analytics, 17 Sep 2024

Parcel 7 reached thirty-eight degrees for nearly four hours and you then tell readers not to worry unduly. I accept the solid-state argument. I would still like to know what the material looked like on analysis, and your article does not say.

L. Whitcombe, Christchurch

The Journal replies

A fair criticism of the reporting. Parcel 7 was submitted for purity determination on arrival and returned a figure within a percentage point of the supplier’s stated value, which is consistent with the solid-state argument and proves very little on its own, since we had no pre-shipment measurement on that vial. The design fault is ours: a shipment study without a paired baseline sample cannot answer the question we most wanted answered, and the next round will.

On “Freezing a reconstituted vial: the ice-water interface problem” — Analytics, 17 Sep 2024

On amber glass: it is not merely cheap, it is standard in the wider chemical supply trade for anything with a chromophore. The fact that this market ships peptides in clear glass is a sign of who is doing the filling more than of any decision about photostability.

J. Mbatha, Durban

On “What the nitrogen said” — Analytics, 17 Sep 2024

I have been buying research peptides for six years and I did not know that the label mass referred to fill mass rather than peptide mass. I have recalculated three years of notes this week. Thank you, I think.

H. Nakagawa, Fukuoka

The Journal replies

You are not unusual in that, which is the reason we ran the piece.

On “What the nitrogen said” — Analytics, 17 Sep 2024

Your table gives vial H at 81% content with 98.9% stated purity. Those two numbers together imply nearly a fifth of the vial is something other than peptide and yet almost none of it shows up chromatographically. Can you explain the mechanism rather than just reporting it?

A. Salcedo, Bilbao

The Journal replies

Water, counter-ion and residual solvent — none of which absorb usefully at 214 nm and none of which are integrated as peaks. Chromatographic purity is calculated on the peptide-derived signal only, so a vial can be simultaneously very pure and largely not peptide. It is the single most consequential thing the two numbers together tell you, and we should have spelled it out in the article rather than in a reply.

On “What the nitrogen said” — Analytics, 17 Sep 2024

As a matter of fairness: the supplier that started reporting content after you contacted them deserves to be named. You name people when they behave badly.

V. Petrosyan, Yerevan

The Journal replies

A fair point. It is Shanghai Sigma-Audley, and the change appeared on certificates from the following quarter.

On “What the trials monitored, and what that implies about routine practice” — Laboratory Notebook, 15 Sep 2024

My HbA1c was 6.1 before starting and 6.0 after four months. My clinic recorded this as no improvement in glycaemic control. My continuous monitor says my average glucose fell by a fifth over the same period. Which is measuring what?

H. Barreto, Recife

The Journal replies

Both are measuring correctly and the discrepancy is worth pursuing with your clinic rather than with us. A 0.1-point change is well inside the reference change value for HbA1c, so the assay has not detected a change; whether that is because the change is genuinely small or because something is affecting your glycation is not answerable from the numbers alone.

On “What the trials monitored, and what that implies about routine practice” — Laboratory Notebook, 15 Sep 2024

You describe the low-T3 pattern during energy restriction as benign adaptation. There is a body of opinion holding that it represents a genuine hypometabolic state requiring treatment. I do not hold that view but your readers will encounter it.

C. Wilcoxson, Des Moines, IA

The Journal replies

They will, and we should have named it in order to say why we do not report it. There is no randomised evidence that treating the low-T3 pattern of energy restriction improves any outcome, and there is a mechanistic argument that suppressing an adaptive response is unlikely to help. We report it as adaptation for those reasons and would report a trial that changed the picture.

On “What the trials monitored, and what that implies about routine practice” — Laboratory Notebook, 15 Sep 2024

You give the reference change value for ALT as about sixty per cent, which strikes me as so large as to make routine monitoring of it pointless. Is that your position?

M. Ferrari, Trieste

The Journal replies

Not quite. It makes monitoring for small movements pointless, which is different. A doubling is well outside the RCV and is a real signal; a rise from 28 to 41 is not. The value of the test lies in detecting the former, and much of the anxiety it generates comes from acting on the latter.

On “What the trials monitored, and what that implies about routine practice” — Laboratory Notebook, 15 Sep 2024

As a biomedical scientist I would add one point to your reference-interval section: many laboratories do not derive their own intervals at all. They adopt the manufacturer interval for the platform, which was established in a population that may have nothing to do with the one being tested. The interval on the report can be a document about a different country.

K. Rautio, Tampere

The Journal replies

This is correct, common, and something we should have stated. We have added it, and it strengthens rather than weakens the argument for within-person comparison.

On “What the trials monitored, and what that implies about routine practice” — Laboratory Notebook, 15 Sep 2024

Your piece assumes readers have a clinician ordering panels for them. A great many of us are buying our own, from services that supply an interval, a flag and nothing else. The apparatus you describe is not available to us at all.

N. Fairweather, Hamilton

The Journal replies

It is available, with effort: published biological variation databases are open, the reference change value is one line of arithmetic, and your own previous result is the comparator that does most of the work. But you are right that the market supplying these panels has no incentive to include any of it, and that is worth stating.

On “The tolerability data everybody quotes and nobody reads” — Pharmacology, 15 Sep 2024

Your figures show diarrhoea at thirty-two per cent and constipation at twenty-three per cent in the same trial arm. I assumed one of these was an error until your mechanism section. It would be worth putting that explanation before the table rather than after it.

F. Okonjo, Asaba

On “The tolerability data everybody quotes and nobody reads” — Pharmacology, 15 Sep 2024

I want to push back on the ginger paragraph. You describe the evidence as transferred from pregnancy and chemotherapy, which is accurate, and then include it in the table anyway. Either it belongs or it does not.

P. Hollingsworth, Norwich

The Journal replies

It belongs, labelled. The table is a map of what is recommended and on what basis, not a list of endorsements, and excluding widely used low-risk measures because their evidence is transferred would make the map less useful rather than more honest. We have made the column heading clearer.

On “The tolerability data everybody quotes and nobody reads” — Pharmacology, 15 Sep 2024

You report the STEP 1 nausea figure as approximately forty-four per cent. The publication gives 44.2 per cent. Given how much of your argument rests on precision about what these numbers mean, the rounding sits oddly.

A. Chowdhury, Dhaka

The Journal replies

Deliberate, and worth explaining. A tenth of a percentage point on a figure with a confidence interval several points wide implies a precision the data does not have. We give the exact figure in the tables and round in prose, which is a convention we should have stated rather than left to be noticed.

On “The tolerability data everybody quotes and nobody reads” — Pharmacology, 15 Sep 2024

I stopped at week six because I could not keep anything down for three days, and my prescriber told me I had not given it a fair chance. Reading your definition of dose-limiting, I think what happened was that nobody offered me the option of going back to the lower dose. It was escalate or stop.

M. Bogdanović, Podgorica

The Journal replies

That binary is the specific failure this file was written against. Stepping back a rung and re-approaching later is permitted in every pivotal protocol in this class and is absent from most conversations about it. We cannot comment on your care, but the framing you were given does not reflect either the trial conduct or the labelling.

On “Twelve minutes or forty: what gradient slope buys” — Explainers, 14 Sep 2024

On response factors: you say correction requires isolated impurity standards, which is true, but you might mention that charged aerosol and mass-based detection sidestep the problem by responding more uniformly. Neither is exotic any more.

B. Ademola, Ilorin

On “Twelve minutes or forty: what gradient slope buys” — Explainers, 14 Sep 2024

Your worked example varies gradient and threshold together and reports a 1.8-point spread. Which of the two contributed more? The article does not say, and the answer matters for what you are asking suppliers to disclose first.

F. Aubert, Toulouse

The Journal replies

Gradient, by roughly two to one in our four conditions: holding the threshold at 0.10 per cent, lengthening the gradient cost 0.9 points, while holding the gradient and tightening the threshold cost 0.4 to 0.9 depending on which gradient. We should have printed that decomposition in the table and it now appears in the note. If a supplier will disclose only one value, it should be the gradient.

On “The lead-in, the randomisation, and the year that followed” — The Ledger, 13 Sep 2024

I lost access for eleven weeks during the shortage, restarted at the dose I had been on because nobody told me otherwise, and spent a fortnight unable to keep food down. I had been on that dose for seven months without difficulty. Reading your resumption section was the first time anybody explained it.

J. Halloway, Dundee

The Journal replies

It is entirely predictable from the label and the pharmacokinetics, and the failure to communicate it during the shortage period was systemic rather than individual. We are sorry it reached you this way and we are glad it reached you.

On “Which results are findings and which are consequences of the weight loss” — Patient Notes, 13 Sep 2024

As a biomedical scientist I would add one point to your reference-interval section: many laboratories do not derive their own intervals at all. They adopt the manufacturer interval for the platform, which was established in a population that may have nothing to do with the one being tested. The interval on the report can be a document about a different country.

K. Erdmann, Leipzig

The Journal replies

This is correct, common, and something we should have stated. We have added it, and it strengthens rather than weakens the argument for within-person comparison.