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 49 of 77 of this archive, newest first.

Page 49 of 77 · back to the first page · 3,055 letters in total

On “Eating enough protein on a suppressed appetite is an arithmetic problem…” — Clinical Trials, 11 Dec 2024

I am sixty-eight, I have lost nineteen kilograms over fourteen months, and my consultant has twice told me my lean mass is fine on the basis of a handheld bioimpedance device in the clinic corridor. Having read your piece on what that device measures, I am no longer sure what I have been reassured about.

M. Halim, Kuala Lumpur

The Journal replies

Nor are we. A handheld device measures impedance across the upper body and infers the rest, and the inference is least reliable exactly where you sit: older, substantial weight change, changing hydration. That is not a criticism of your consultant’s judgement, which may be sound on other grounds, but the device is not the evidence for it.

On “Eating enough protein on a suppressed appetite is an arithmetic problem…” — Clinical Trials, 11 Dec 2024

Small correction to your table: the S-LiTE exercise prescription was two supervised group sessions and two individual sessions weekly, not two sessions in total. The distinction matters because "add some exercise" is not what was tested.

I. Mukherjee, Kolkata

The Journal replies

Correct, and that is precisely the point we were trying to make and then undermined in our own table. Amended.

On “A guide to the results that will resolve themselves” — Laboratory Notebook, 9 Dec 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.

O. Brannigan, Galway

On “A guide to the results that will resolve themselves” — Laboratory Notebook, 9 Dec 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?

G. Papadakis, Thessaloniki

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 “A guide to the results that will resolve themselves” — Laboratory Notebook, 9 Dec 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?

N. Fairweather, Hamilton

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 “A guide to the results that will resolve themselves” — Laboratory Notebook, 9 Dec 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.

M. Karlsen, Kristiansand

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 “A guide to the results that will resolve themselves” — Laboratory Notebook, 9 Dec 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?

M. Ferrari, Trieste

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 “Albumin, fatty-acid chains, and the engineering that made a weekly incretin…” — Explainers, 9 Dec 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.

V. Bhattarai, Kathmandu

The Journal replies

Fair, and now stated in the text.

On “Albumin, fatty-acid chains, and the engineering that made a weekly incretin…” — Explainers, 9 Dec 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.

N. Prasetyo, Surabaya

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 “The badge is about a sample. The listing is about a product.” — Analytics, 7 Dec 2024

VendorInvestigate does not measure anything and you have grouped it with three laboratories under the heading independent testing. That is exactly the conflation your article says the market makes.

I. Mukherjee, Kolkata

The Journal replies

A fair hit. The tag under which this coverage sits predates the distinction we now draw, and we have added the distinction to the second paragraph and to the table. The department name will follow at the next reorganisation of the site.

On “In-use periods, and the ones nobody can give you” — Patient Notes, 7 Dec 2024

You recommend writing the concentration on the vial. I would add: write it on the box as well. My vial label came off in the fridge and I lost the only record of what diluent volume I had used.

R. Ekwueme, Awka

On “One vial, four weeks, and the data that does not exist” — Analytics, 6 Dec 2024

I have shipped temperature-sensitive material commercially for eleven years and your coolant arithmetic is right but generous. You assume the pack starts fully frozen. In practice packs are pulled from a freezer that is opened forty times a day, and a pack that starts at minus four with a soft core has lost a fair share of its budget before the box is closed.

C. Rautenbach, Pretoria

The Journal replies

A good point and one we had not considered properly. The latent heat calculation assumes a fully solid pack at its melting point, and a partially thawed pack is exactly as much worse as the missing solid fraction. We have added a sentence and would welcome any data you can share on pack condition at packing.

On “One vial, four weeks, and the data that does not exist” — Analytics, 6 Dec 2024

You say no company reports residual moisture. I obtained a figure from a supplier last year without difficulty, on request, so the data exists in at least some cases. The problem may be less that it is not measured than that it is not printed.

R. Whitlam, Adelaide, SA

On “One vial, four weeks, and the data that does not exist” — Analytics, 6 Dec 2024

Eleven days in customs, and you describe it as a structural feature rather than a scandal. Why the restraint? A shipper advertising a cold chain that demonstrably does not survive a routine examination is making a claim it cannot support.

A. Mbeki, Lusaka

The Journal replies

The restraint is about where the fault lies. Customs authorities are performing a lawful function and owe nobody a thermal record. The claim of end-to-end control is the thing we criticise, and we do criticise it, in the article and again in the closing. What we will not do is convert an unavoidable feature of international freight into an allegation against the shipper who could not see it either.

On “One vial, four weeks, and the data that does not exist” — Analytics, 6 Dec 2024

Your section on freezing reconstituted solution stops short of the obvious question, which I will therefore ask. If a phosphate buffer shifts pH substantially on freezing, does that not mean the freezer is actively worse than the refrigerator for a buffered formulation, rather than merely unproven?

D. Mazzarella, Catania

The Journal replies

For a phosphate-buffered formulation, plausibly yes, and the mechanism is well documented. We stopped short because the magnitude is formulation-specific and because most reconstituted research vials are in unbuffered water or bacteriostatic water, where the argument is about the interface rather than about pH. We should have made that distinction in the text instead of leaving a gap for you to find.

On “We asked four laboratories for a sterility test. Here is what came back.” — The Supply Chain, 6 Dec 2024

Why did you submit only two vials for sterility testing when the whole article argues that the sample size is the problem? Two is worse than twenty by exactly the argument you make.

T. Kirchner, Hamburg

The Journal replies

Because we could not afford twenty, and because the two results are reported as what they are: two vials, each destroyed, telling us nothing about their batches. The purpose was to establish that the test is commercially available to a private purchaser and what it costs, not to characterise anything. We should have said that in the article rather than in this reply.

On “We asked four laboratories for a sterility test. Here is what came back.” — The Supply Chain, 6 Dec 2024

On multiple-dose closures: the puncture budget you refer to is generally in single figures for a standard lyophilisation stopper, and the qualification uses a new needle each time. Anybody reusing a needle through the same entry point is outside the data entirely.

S. Nortje, Stellenbosch

On “We asked four laboratories for a sterility test. Here is what came back.” — The Supply Chain, 6 Dec 2024

You keep saying you are criticising documentation and not honesty. I think that distinction is doing more work than it can bear. If a company knows buyers read a purity certificate as a safety document and issues one anyway, the omission is doing something.

F. Duquesne, Lyon

The Journal replies

It is a fair challenge and we have thought about it. Our answer is that the convention long predates any individual company’s decision to follow it, that four of our correspondents told us plainly the products are not represented as sterile injectables, and that we have no evidence of anybody intending the inference readers draw. We will report intent when we can demonstrate it and not before.

On “We asked four laboratories for a sterility test. Here is what came back.” — The Supply Chain, 6 Dec 2024

I photograph every cake now because of an earlier piece of yours, and last month it paid for itself. Two vials from the same box, one a proper matte plug and one a collapsed glassy disc. The supplier replaced both without argument when I sent the photographs.

N. Ó Broin, Sligo

On “We asked four laboratories for a sterility test. Here is what came back.” — The Supply Chain, 6 Dec 2024

You write that recombinant factor C is insensitive to the glucan branch of the cascade. It would be worth adding why anybody cares: cellulose filter media and certain paper wrappings shed glucans, and a laboratory that has chased a false positive through three repeat assays will never willingly go back to a reagent that responds to them.

A. Fournier, Nantes

On “What changed after we published the first version of this” — Laboratory Notebook, 4 Dec 2024

You keep saying you are criticising documentation and not honesty. I think that distinction is doing more work than it can bear. If a company knows buyers read a purity certificate as a safety document and issues one anyway, the omission is doing something.

T. Nkemelu, Port Harcourt

The Journal replies

It is a fair challenge and we have thought about it. Our answer is that the convention long predates any individual company’s decision to follow it, that four of our correspondents told us plainly the products are not represented as sterile injectables, and that we have no evidence of anybody intending the inference readers draw. We will report intent when we can demonstrate it and not before.

On “Maintenance dosing: what is licensed, what is practised, and what is evidenced” — Clinical Trials, 3 Dec 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.

A. Petrucci, Bari

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 “Maintenance dosing: what is licensed, what is practised, and what is evidenced” — Clinical Trials, 3 Dec 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.

D. Ferreira-Lopes, Porto

On “Maintenance dosing: what is licensed, what is practised, and what is evidenced” — Clinical Trials, 3 Dec 2024

Your fortnightly arithmetic table is correct but I think it understates the practical point. A fourfold peak-to-trough swing is not merely lower average exposure; it is a different drug experience, with the last few days of each cycle spent at a concentration the person has effectively titrated off.

F. Aubert, Toulouse

The Journal replies

Well put, and better than our own phrasing. We have adopted the point in the text with attribution to a reader.

On “Maintenance dosing: what is licensed, what is practised, and what is evidenced” — Clinical Trials, 3 Dec 2024

Three months after stopping, my HbA1c had barely moved and I concluded I had got away with it. Six months after stopping, it was back where it started. Your point about the lag is the single most useful sentence I have read on this subject.

B. Ademola, Ilorin

On “Maintenance dosing: what is licensed, what is practised, and what is evidenced” — Clinical Trials, 3 Dec 2024

Your piece describes tapering as pharmacologically pointless and then spends three paragraphs making a case for it. Pick one.

D. Chukwuma, Onitsha

The Journal replies

Both, we think, and deliberately. There is no pharmacological rationale, because there is no withdrawal syndrome and a week-long half-life produces its own decline. There is a behavioural rationale, which is different in kind and untested. Our objection is to tapers advocated in pharmacological language, not to the practice.

On “The lowest effective dose is a real concept with almost no data behind it” — The Ledger, 3 Dec 2024

Your piece describes tapering as pharmacologically pointless and then spends three paragraphs making a case for it. Pick one.

P. Vuković, Split

The Journal replies

Both, we think, and deliberately. There is no pharmacological rationale, because there is no withdrawal syndrome and a week-long half-life produces its own decline. There is a behavioural rationale, which is different in kind and untested. Our objection is to tapers advocated in pharmacological language, not to the practice.

On “The lowest effective dose is a real concept with almost no data behind it” — The Ledger, 3 Dec 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.

L. Marulanda, Medellín

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 “Dose-limiting: a definition worth being strict about” — Patient Notes, 2 Dec 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.

H. Ravensworth, York

On “Benzyl alcohol is a preservative, not a sterilising agent” — The Supply Chain, 1 Dec 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?

E. Sørheim, Stavanger

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 “Benzyl alcohol is a preservative, not a sterilising agent” — The Supply Chain, 1 Dec 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.

H. Steinmetz, Basel

On “EGFR, cystatin C, and the check on the check” — Clinical Trials, 1 Dec 2024

Correction to your HbA1c section. You write that chronic kidney disease lowers HbA1c through shortened erythrocyte survival. It can also raise measured values on some assay platforms through carbamylated haemoglobin interference. The net direction depends on the method.

B. Osei-Bonsu, Kumasi

The Journal replies

Correct, and the omission was ours. The paragraph now says so, and it is a good example of why the assay method belongs alongside the value.

On “EGFR, cystatin C, and the check on the check” — Clinical Trials, 1 Dec 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.

L. Kowalski, Gdańsk

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 “EGFR, cystatin C, and the check on the check” — Clinical Trials, 1 Dec 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?

M. Halim, Kuala Lumpur

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 “EGFR, cystatin C, and the check on the check” — Clinical Trials, 1 Dec 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.

I. Mukherjee, Kolkata

On “EGFR, cystatin C, and the check on the check” — Clinical Trials, 1 Dec 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.

H. Okwuosa, Enugu

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 “LAL, kinetic chromogenic, recombinant factor C: three ways to the same figure” — Analytics, 28 Nov 2024

A quibble about depyrogenation. You imply an operation describing autoclaving alone has skipped a step, but depyrogenation of glass is only necessary if the incoming glass carries endotoxin. Vials supplied ready-to-use from a component manufacturer arrive already depyrogenated and certified as such.

E. Thistlethwaite, Sheffield

The Journal replies

Correct, and the text now says so. A ready-to-use component with a certificate stating its endotoxin limit is a perfectly good answer to the question; what is not an answer is autoclaving ordinary glass and describing the result as pyrogen-free.

On “LAL, kinetic chromogenic, recombinant factor C: three ways to the same figure” — Analytics, 28 Nov 2024

The statistics section is the part of this I will be sending to people. I had assumed a passed sterility test meant something about the batch. It had not occurred to me that a batch with one contaminated vial in a hundred passes four times out of five.

V. Petrosyan, Yerevan

On “LAL, kinetic chromogenic, recombinant factor C: three ways to the same figure” — Analytics, 28 Nov 2024

You write that recombinant factor C is insensitive to the glucan branch of the cascade. It would be worth adding why anybody cares: cellulose filter media and certain paper wrappings shed glucans, and a laboratory that has chased a false positive through three repeat assays will never willingly go back to a reagent that responds to them.

A. Salcedo, Bilbao

On “LAL, kinetic chromogenic, recombinant factor C: three ways to the same figure” — Analytics, 28 Nov 2024

Your endotoxin table gives vial 12 at 112 EU per vial and then declines to say whether that is dangerous. I understand why. It is still frustrating to read a figure of that size next to the sentence "arithmetic, not a safety assessment".

H. Nakagawa, Fukuoka

The Journal replies

We understand the frustration and we are going to keep doing it. The figure sits at roughly a third of the hourly systemic allowance for a 70 kg adult if the whole vial were administered at once, which is a comparison a reader can make. What we cannot do is turn a single determination on one vial into a statement about a person, and pretending otherwise would be the more serious failure.