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 10 of 77 of this archive, newest first.

Page 10 of 77 · back to the first page · 3,055 letters in total

On “Accreditation, scope, and the question nobody asks Medutest” — The Supply Chain, 12 Mar 2026

Nine years buying research chemicals and I had never once looked at the date of manufacture. I checked eleven certificates in my drawer this evening. Four do not carry one.

A. Kirkbride, Leeds

On “The one randomised trial that combined an incretin with supervised exercise” — Clinical Trials, 11 Mar 2026

I have read your protein tables twice and I still cannot work out what I should eat. I appreciate that this is the honest position but it is not a useful one for a person in a supermarket.

N. Prasetyo, Surabaya

The Journal replies

It is a fair complaint about a real limitation. What we can say is that the defensible range is narrower than the disagreement suggests, that the denominator matters more than the ratio, and that a clinician or dietitian can convert a range into a number for your body in a way that a magazine cannot.

On “The one randomised trial that combined an incretin with supervised exercise” — Clinical Trials, 11 Mar 2026

Three vendors have now sent me marketing material claiming their product preserves lean mass during GLP-1 treatment, two of them citing your publication as a source for the underlying composition figures. You may want to know that.

V. Bhattarai, Kathmandu

The Journal replies

We did not, and we are grateful. Quoting our reporting of a substudy alongside an unevidenced product claim is a misuse of it, and the standards desk has written to all three.

On “The one randomised trial that combined an incretin with supervised exercise” — Clinical Trials, 11 Mar 2026

The soft-tissue artefact point in your bone section is underplayed. In a patient losing twenty per cent of body mass the change in overlying tissue is well outside the range the calibration was validated over, and the published analyses do not report a sensitivity analysis for it. That is not a caveat, it is a gap.

P. Sarkissian, Beirut

The Journal replies

We accept the escalation and have strengthened the wording. The absence of any published sensitivity analysis is, as you say, the more damaging observation.

On “The one randomised trial that combined an incretin with supervised exercise” — Clinical Trials, 11 Mar 2026

My mother is eighty-one and on a low dose for her diabetes. Her weight is down nine kilograms and she now struggles to get out of a low chair, which she did not eighteen months ago. Nobody has measured anything. I do not know whether this is the drug, the weight loss, or being eighty-one, and neither does anybody I have asked.

J. Delahunty, Waterford

The Journal replies

That is the situation the missing endpoint produces, and we are sorry to have no better answer. A chair-stand time takes thirty seconds to measure and would at least establish a baseline against which the next six months could be judged. It is worth asking for by name.

On “The one randomised trial that combined an incretin with supervised exercise” — Clinical Trials, 11 Mar 2026

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

E. Nkomo, Polokwane

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 “Load, not cardio: the distinction the general advice keeps losing” — Patient Notes, 9 Mar 2026

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. Petrucci, Bari

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 “Load, not cardio: the distinction the general advice keeps losing” — Patient Notes, 9 Mar 2026

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

D. Ferreira-Lopes, Porto

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 “Load, not cardio: the distinction the general advice keeps losing” — Patient Notes, 9 Mar 2026

My mother is eighty-one and on a low dose for her diabetes. Her weight is down nine kilograms and she now struggles to get out of a low chair, which she did not eighteen months ago. Nobody has measured anything. I do not know whether this is the drug, the weight loss, or being eighty-one, and neither does anybody I have asked.

F. Aubert, Toulouse

The Journal replies

That is the situation the missing endpoint produces, and we are sorry to have no better answer. A chair-stand time takes thirty seconds to measure and would at least establish a baseline against which the next six months could be judged. It is worth asking for by name.

On “What the trials monitored, and what that implies about routine practice” — Clinical Trials, 8 Mar 2026

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?

A. Lindholm, Gothenburg

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” — Clinical Trials, 8 Mar 2026

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. Suárez, Montevideo

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” — Clinical Trials, 8 Mar 2026

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. Guðmundsdóttir, Reykjavík

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 “One receptor, several signals: the case for reading semaglutide as a biased…” — Pharmacology, 7 Mar 2026

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.

B. Sundqvist, Turku

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 “One receptor, several signals: the case for reading semaglutide as a biased…” — Pharmacology, 7 Mar 2026

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.

H. Fitzmaurice, Preston

The Journal replies

Fair, and now stated in the text.

On “How a peptide that lasts seven days binds a receptor that recycles in minutes” — Pharmacology, 6 Mar 2026

Your table lists orforglipron with a half-life of 29 to 49 hours. That is a wide range to report as a single figure. What accounts for it?

G. Escalante, Lima

The Journal replies

Dose and study population, mostly. We should have given the two bounding studies rather than a range with no attribution, and the table has been amended.

On “How a peptide that lasts seven days binds a receptor that recycles in minutes” — Pharmacology, 6 Mar 2026

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.

D. Iversen, Aalborg

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 “How a peptide that lasts seven days binds a receptor that recycles in minutes” — Pharmacology, 6 Mar 2026

I have read three separate articles this month describing cagrilintide as a GLP-1 agonist and one describing tirzepatide as "semaglutide with an extra bit". Thank you for the glossary. Please run it again.

M. Fitzhenry, Cork

On “How a peptide that lasts seven days binds a receptor that recycles in minutes” — Pharmacology, 6 Mar 2026

The claim that nothing at baseline predicts response is too strong. Surely baseline BMI, sex and diabetes status shift the expected outcome — the trials stratify on exactly those variables.

A. Nazarian, Glendale, CA

The Journal replies

They shift the mean, which is why the trials stratify. They barely narrow the distribution around it, which is the claim we made. Both statements are in the responder analyses and we should have distinguished them more carefully in the paragraph you are objecting to.

On “How a peptide that lasts seven days binds a receptor that recycles in minutes” — Pharmacology, 6 Mar 2026

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.

L. Whitcombe, Christchurch

On “The submitted sample: the weakest link in the whole system” — The Ledger, 5 Mar 2026

You note that no service offers sterility testing and that it takes fourteen days. Worth saying more plainly: a purity certificate and a sterility assurance are not merely different tests, they are different disciplines with different facilities, and no amount of chromatography will ever bear on it.

V. Bhattarai, Kathmandu

The Journal replies

Correct and worth the emphasis. We have said it in the certificates piece and should say it here too: nothing any of these four services sells addresses sterility, endotoxin or container closure integrity, and no combination of their reports adds up to one.

On “The submitted sample: the weakest link in the whole system” — The Ledger, 5 Mar 2026

The price table is the most useful thing you have published this year and also the thing most likely to be quoted out of context by somebody selling a comparison service. You might consider a note.

N. Prasetyo, Surabaya

The Journal replies

There is one, and we have strengthened it. The figures are what this publication was invoiced at list rates and are not quotations a reader should expect; volume submitters pay materially less.

On “A unit is not a dose, and it never was” — Patient Notes, 4 Mar 2026

A quibble on your dead-space figure. You give two to seven microlitres for insulin-type needles, which is right for fixed-needle syringes, but the detachable pen needle plus syringe hub combinations sold in this market are considerably worse and you should say so.

H. Ravensworth, York

The Journal replies

Accepted and amended. The figure we gave applies to integrated fixed-needle insulin syringes; detachable arrangements on a luer fitting can retain an order of magnitude more, which at small injection volumes is a substantial loss. The table now distinguishes them.

On “A unit is not a dose, and it never was” — Patient Notes, 4 Mar 2026

You spend a page on the four-line calculation and then publish a reconstitution table anyway. Are you not providing exactly the pre-computed number you warned against?

E. Marchetti, Bologna

The Journal replies

A fair catch, and the reason the table carries the note it does. It is indexed by both vial mass and diluent volume precisely so that it cannot be read as a single fixed answer, and it is preceded by the derivation. If we thought a reader would take one figure from it and carry that figure across a change of vial, we would remove it.

On “A unit is not a dose, and it never was” — Patient Notes, 4 Mar 2026

Nothing in this file addresses what to do when you realise mid-week that you have made an error. I gave double my dose on a Sunday and could find no guidance anywhere about what that meant.

L. Dziedzic, Wrocław

The Journal replies

A real gap and we will address it properly rather than in a reply. The short version is that it is a pharmacokinetic question — how much excess exposure, over what half-life — and a clinical one about symptom burden, and neither is answerable in the abstract. It also belongs in the titration file, which currently discusses omission and not excess.

On “Reading the mazdutide titration schedule as a regulatory artefact” — Explainers, 3 Mar 2026

Thank you for saying plainly that the maximum dose is not the goal. I stopped at 10 mg fourteen months ago because it was working and I was tired of arguing about it. Every article I read before yours implied I had given up early.

N. Ó Broin, Sligo

On “Reading the mazdutide titration schedule as a regulatory artefact” — Explainers, 3 Mar 2026

I want to object to the framing of dose reduction as measurement. In practice it is experienced as failure, and telling people it is a thermostat does not change how the appointment feels. The language problem is real and you have solved it rhetorically rather than actually.

F. Duquesne, Lyon

The Journal replies

A fair hit. We can describe the pharmacology accurately and still be writing at a distance from how the decision lands, and the paragraph you object to does both. The reframing is offered as a corrective to a stigma, not as a claim that the stigma is imaginary.

On “Reading the mazdutide titration schedule as a regulatory artefact” — Explainers, 3 Mar 2026

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.

S. Nortje, Stellenbosch

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 “The skeleton responds to load, and load is falling” — Clinical Trials, 3 Mar 2026

My mother is eighty-one and on a low dose for her diabetes. Her weight is down nine kilograms and she now struggles to get out of a low chair, which she did not eighteen months ago. Nobody has measured anything. I do not know whether this is the drug, the weight loss, or being eighty-one, and neither does anybody I have asked.

S. Bergqvist, Malmö

The Journal replies

That is the situation the missing endpoint produces, and we are sorry to have no better answer. A chair-stand time takes thirty seconds to measure and would at least establish a baseline against which the next six months could be judged. It is worth asking for by name.

On “The skeleton responds to load, and load is falling” — Clinical Trials, 3 Mar 2026

The soft-tissue artefact point in your bone section is underplayed. In a patient losing twenty per cent of body mass the change in overlying tissue is well outside the range the calibration was validated over, and the published analyses do not report a sensitivity analysis for it. That is not a caveat, it is a gap.

T. Oyelowo, Abeokuta

The Journal replies

We accept the escalation and have strengthened the wording. The absence of any published sensitivity analysis is, as you say, the more damaging observation.

On “The skeleton responds to load, and load is falling” — Clinical Trials, 3 Mar 2026

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.

J. Vasilenko, Chisinau

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 “Holidays, surgery, sickness: interruption in practice” — Pharmacology, 2 Mar 2026

I had a nine-week gap last year because my supplier stopped answering messages. Nobody in any clinical setting I dealt with treated that as a pharmacological event. Your framing of supply interruption as a dosing decision is the first time I have seen it written down.

T. Kirchner, Hamburg

On “Holidays, surgery, sickness: interruption in practice” — Pharmacology, 2 Mar 2026

A small thing. You give the semaglutide diabetes ladder as ending at 2.0 mg and the weight ladder at 2.4 mg, without explaining why the same molecule has two ceilings for two indications. It looks arbitrary and I suspect it is not.

S. Nortje, Stellenbosch

The Journal replies

It is not arbitrary — the two maxima come from separate dose-selection programmes with different primary endpoints, and 2.0 mg was established against 1.0 mg in a dedicated glycaemic comparison. We have added a clause. The underlying point, that indication shapes the ladder as much as the molecule does, is worth more space than we gave it.

On “Holidays, surgery, sickness: interruption in practice” — Pharmacology, 2 Mar 2026

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.

F. Duquesne, Lyon

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 “Holidays, surgery, sickness: interruption in practice” — Pharmacology, 2 Mar 2026

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. Ó Broin, Sligo

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 “The degradation product that elutes underneath the parent peak” — The Supply Chain, 2 Mar 2026

The mean kinetic temperature explanation is the clearest I have read anywhere, including in the training my employer paid for. I have printed the sidebar and put it on the wall of the dispatch room.

J. Delahunty, Waterford

On “The degradation product that elutes underneath the parent peak” — The Supply Chain, 2 Mar 2026

Your table of degradation pathways lists racemisation and then says it is essentially never reported. If it is never reported, on what basis do you list it as a real risk rather than a theoretical one?

P. Sarkissian, Beirut

The Journal replies

On the basis of the synthesis and analytical literature, where epimer formation during solid-phase assembly and during storage at extremes of pH is well characterised. What is missing is not evidence that it occurs but evidence about how much of it is present in any particular commercial vial, which is a different absence and the one we should have named.

On “The degradation product that elutes underneath the parent peak” — The Supply Chain, 2 Mar 2026

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.

V. Bhattarai, Kathmandu

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 “What orthogonal actually means, and what it does not” — Laboratory Notebook, 1 Mar 2026

You list five things a purity figure cannot tell you and then say the list is not an indictment of the technique. It reads like one. If a measurement is silent on content, aggregation, sequence, isomers and microbiology, why is it the measurement this market uses at all?

J. Costanzo, Naples

The Journal replies

Because it is cheap, fast, comparable-looking and genuinely informative about the thing it measures. A tyre pressure gauge is silent on tread depth, brake pads and the driver, and it is still the right instrument for its question. The failure is in a market that owns one gauge and calls the reading roadworthiness.

On “Nine parcels, nine loggers, and one uncomfortable set of traces” — Laboratory Notebook, 1 Mar 2026

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?

W. Stroud, Chattanooga, TN

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 “Nine parcels, nine loggers, and one uncomfortable set of traces” — Laboratory Notebook, 1 Mar 2026

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.

R. Devaney, Ballarat, VIC

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.