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 70 of 77 of this archive, newest first.

Page 70 of 77 · back to the first page · 3,055 letters in total

On “The three-times-upper-limit convention, and where it came from” — Clinical Trials, 23 Mar 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.

N. Zangwill, Manchester

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 “The three-times-upper-limit convention, and where it came from” — Clinical Trials, 23 Mar 2024

A small thing but it matters in practice: your table gives amylase and lipase rising as a finding of unclear significance. In my laboratory we no longer report amylase at all for suspected pancreatitis, because lipase is more sensitive and more specific and having both invites the wrong one to be acted on.

P. Havlíček, Brno

The Journal replies

A reasonable position and increasingly the standard one. We report amylase because the trial data reported it, not because we think it should be ordered.

On “The three-times-upper-limit convention, and where it came from” — Clinical Trials, 23 Mar 2024

My ferritin fell from 118 to 34 across a year on treatment and I was told this was expected because inflammation had fallen. Six months later I was clearly iron deficient. I appreciate the section on this being ambiguous, but the ambiguity was resolved in one direction and nobody looked.

B. Achterberg, Utrecht

The Journal replies

That is the failure mode the ambiguity produces, and it is the reason a transferrin saturation alongside costs almost nothing and resolves the question. We are sorry it went that way.

On “The three-times-upper-limit convention, and where it came from” — Clinical Trials, 23 Mar 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.

C. Tremonti, Palermo

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 “Who signed this, and what did they undertake by signing it” — The Supply Chain, 22 Mar 2024

The most useful sentence in the piece is the one saying a bad document is not a bad product. I have spent two years on forums watching people conclude the opposite from a missing signature block, and it has made the whole conversation about honesty rather than about paperwork.

J. Delahunty, Waterford

The Journal replies

That inversion is the reason we wrote the final section, and we would rather be accused of excessive caution than contribute to it.

On “Who signed this, and what did they undertake by signing it” — The Supply Chain, 22 Mar 2024

I supply research peptides and I want to push back on the specification column point. We sell from a catalogue of six hundred products. Writing a meaningful individual specification for each would take a year of somebody’s time, and a generic one would be exactly the decorative limit your article criticises. What would you actually have us do?

P. Sarkissian, Beirut

The Journal replies

A fair challenge. Our answer is that a generic limit stated honestly is better than no limit at all, provided the typical result is also published so a reader can see the margin. What we object to is a decorative limit presented as a control. Publishing your process capability alongside it removes the objection entirely, and costs you a spreadsheet.

On “Who signed this, and what did they undertake by signing it” — The Supply Chain, 22 Mar 2024

Your ten-minute check told me in about ninety seconds that the batch number on my certificate appears nowhere on the vial. I wrote to the supplier and had a straightforward answer within a day: the certificate covers the bulk lot and the vial carries a fill code. I would never have known to ask.

V. Bhattarai, Kathmandu

The Journal replies

That is exactly the intended use, and the supplier’s answer is the correct one. The remaining question is why the relationship between the two codes is not printed on the document, since it takes a line.

On “Who signed this, and what did they undertake by signing it” — The Supply Chain, 22 Mar 2024

You describe reused chromatogram images as a tell. I work in a contract laboratory and I would note that some data systems export a representative overlay rather than the individual injection, so identical-looking traces can occur legitimately across a batch series. It is still worth asking about; it is not the smoking gun your article implies.

N. Prasetyo, Surabaya

The Journal replies

A useful qualification and the text has been softened. The observation remains worth making; the inference we drew from it was stronger than the practice supports.

On “Who signed this, and what did they undertake by signing it” — The Supply Chain, 22 Mar 2024

On the accreditation-scope point: most private buyers will not know which accreditation body to search. It would be more useful to publish the four or five registers that cover the laboratories this market actually uses than to tell readers the registers exist.

G. Rasmussen, Odense

The Journal replies

Agreed, and the standards desk is compiling exactly that. It will appear as a standing reference page rather than inside an article, so that it can be kept current.

On “How a correct calculation becomes a wrong dose” — Laboratory Notebook, 21 Mar 2024

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.

E. Vandenberghe, Ghent

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 “How a correct calculation becomes a wrong dose” — Laboratory Notebook, 21 Mar 2024

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?

H. Okwuosa, Enugu

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 “What TRIUMPH-3 tells us about maintenance, and what it does not” — The Ledger, 20 Mar 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.

J. Halloway, Dundee

On “What TRIUMPH-3 tells us about maintenance, and what it does not” — The Ledger, 20 Mar 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.

K. Oyibo, Benin City

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 “What TRIUMPH-3 tells us about maintenance, and what it does not” — The Ledger, 20 Mar 2024

You say no dose-equivalence data exists between agents in this class. During the shortage my pharmacy substituted one for another on the basis of a conversion table they had printed from somewhere. Where would such a table have come from?

K. Erdmann, Leipzig

The Journal replies

Almost certainly from cross-trial comparison of weight-loss percentages, which is not an equivalence basis. There is no head-to-head dose-titration study permitting conversion between these agents, and STEP 8 — the only head-to-head weight trial we know of — compared two agents at their own licensed doses rather than establishing equivalence between them.

On “What TRIUMPH-3 tells us about maintenance, and what it does not” — The Ledger, 20 Mar 2024

As a prescriber I would push back on your framing of the maintenance gap. We are not practising without evidence; we are practising on pharmacological inference, which is what clinicians do in every field where the trial has not been run. Calling it unevidenced makes reasonable practice sound reckless.

Z. Karadzic, Novi Sad

The Journal replies

A fair objection and we have adjusted the wording. Our intention was to locate the absence with the people who could have funded the trial rather than with the clinicians managing without it, and on rereading the original paragraph did not achieve that.

On “What TRIUMPH-3 tells us about maintenance, and what it does not” — The Ledger, 20 Mar 2024

I stopped eight months ago after reaching a weight I was happy with, and I have regained four of the twenty-two kilograms I lost. Every article I read told me to expect two-thirds back. I am not complaining, but I would like to know whether I am unusual or whether the two-thirds figure was always a mean concealing an enormous range.

E. Marchbank, Perth, WA

The Journal replies

The second. The published interquartile ranges around those means are wide, and outcomes like yours are well within them. The trials were not designed to explain why some people hold weight after cessation and others do not, and nothing measured at randomisation predicts it usefully. You are not an anomaly; you are part of a distribution nobody quotes.

On “The dose that got you here and the dose that keeps you here” — Clinical Trials, 18 Mar 2024

You describe the maintenance strategy of stepping down one dose and holding for eight to twelve weeks as something clinicians report doing, and then say it is not a recommendation. That distinction will be lost on most readers, and printing the protocol makes you a source for it whether you intend to be or not.

Z. Karadzic, Novi Sad

The Journal replies

This is the hardest editorial question this department faces and we do not think you are wrong. Our position is that a practice this widespread is better described accurately, with its evidentiary status stated, than left to circulate in fragments. We accept that the distinction does work that a reader may not do.

On “The dose that got you here and the dose that keeps you here” — Clinical Trials, 18 Mar 2024

I stopped eight months ago after reaching a weight I was happy with, and I have regained four of the twenty-two kilograms I lost. Every article I read told me to expect two-thirds back. I am not complaining, but I would like to know whether I am unusual or whether the two-thirds figure was always a mean concealing an enormous range.

K. Erdmann, Leipzig

The Journal replies

The second. The published interquartile ranges around those means are wide, and outcomes like yours are well within them. The trials were not designed to explain why some people hold weight after cessation and others do not, and nothing measured at randomisation predicts it usefully. You are not an anomaly; you are part of a distribution nobody quotes.

On “The dose that got you here and the dose that keeps you here” — Clinical Trials, 18 Mar 2024

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

K. Oyibo, Benin City

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 dose that got you here and the dose that keeps you here” — Clinical Trials, 18 Mar 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 “The dose that got you here and the dose that keeps you here” — Clinical Trials, 18 Mar 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.

H. Fitzmaurice, Preston

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 “What the GLP-1 receptor actually does when mazdutide binds it” — Pharmacology, 17 Mar 2024

Your accumulation table gives 2.0 for a seven-day half-life at weekly dosing. I make it 2.0 as well, but I would point out that this assumes complete absorption of each dose, which for subcutaneous peptides is a generous assumption.

K. Sivertsen, Bergen

The Journal replies

Correct, and the table now carries that caveat. The ratio is unaffected by a constant bioavailability factor, but the absolute concentrations obviously are.

On “What the GLP-1 receptor actually does when mazdutide binds it” — Pharmacology, 17 Mar 2024

As a community pharmacist I would add one thing to your section on missed doses: the label window matters less than whether the patient then double-doses to "catch up". I have seen that twice this year and both times the patient believed they were following instructions.

J. Vasilenko, Chisinau

The Journal replies

Noted, and worth stating plainly: the pharmacokinetics give no basis whatever for doubling a dose after an omission. We will say so explicitly next time the subject comes up.

On “What the GLP-1 receptor actually does when mazdutide binds it” — Pharmacology, 17 Mar 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.

T. Oyelowo, Abeokuta

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 “What the GLP-1 receptor actually does when mazdutide binds it” — Pharmacology, 17 Mar 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.

S. Bergqvist, Malmö

On “Reflux, early satiety, and the volume the stomach will accept” — Explainers, 16 Mar 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.

R. Ekwueme, Awka

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 badge is about a sample. The listing is about a product.” — The Ledger, 15 Mar 2024

I submitted a vial to one of these services last year, got a result three points below what the vendor advertised, and did not know what to do with it. Your article explains why: I had one measurement on one vial, no method comparison, and no way to know if my vial was representative. I still do not know what to do with it, but I understand the shape of not knowing.

D. Chukwuma, Onitsha

The Journal replies

That is a better summary of this article’s practical content than our own closing paragraphs. The one thing we would add is that your result is worth publishing wherever you can, because buyer-submitted results are the scarcest and most informative category in the entire corpus.

On “The badge is about a sample. The listing is about a product.” — The Ledger, 15 Mar 2024

I run analytical services and I object to the framing of your blind comparison. You bought our cheapest tier, published the number it produced alongside a competitor’s most thorough package, and called the result a spread. It is not a spread. It is three different products, priced accordingly, and your own table says so two columns to the right of the headline figure.

M. Sandhu, Amritsar

The Journal replies

This is the objection we thought was most likely and we think it is partly right. The comparison is of standard products at standard prices, which is what buyers actually purchase, and we said so. But the presentation invites the reading you object to, and the figure caption now states the tier alongside each result rather than leaving it to the method columns.

On “The badge is about a sample. The listing is about a product.” — The Ledger, 15 Mar 2024

Your suggestion that laboratories publish the fact of a submission while keeping the result confidential is the first proposal I have read in this area that a laboratory could actually implement without breaching a client obligation. I have raised it internally.

A. Basaraba, Winnipeg, MB

The Journal replies

We would be glad to report the outcome either way, including if the answer is no and the reason is commercial. The proposal is only useful if somebody adopts it, and a published refusal is more informative than silence.

On “Aggregation: the impurity your chromatogram dissolved before it looked” — Analytics, 14 Mar 2024

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.

B. Wojciechowski, Kraków

On “Lean mass is a compartment, not a tissue” — Clinical Trials, 13 Mar 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.

E. Beauchamp, Ottawa, ON

On “Lean mass is a compartment, not a tissue” — Clinical Trials, 13 Mar 2024

Your piece treats the one-quarter rule as discredited and then quotes fractions of one third and two fifths from the substudies as though those were more solid. They are group means from a hundred and forty people. Physician, heal thyself.

L. Dziedzic, Wrocław

The Journal replies

A fair hit, and we have amended the paragraph to carry the same caveat in both places. The distinction we should have drawn is that the substudy figures are at least attached to a stated population and a stated instrument, which the textbook rule is not. Neither is a constant.

On “Lean mass is a compartment, not a tissue” — Clinical Trials, 13 Mar 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.

E. Marchetti, Bologna

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 “Lean mass is a compartment, not a tissue” — Clinical Trials, 13 Mar 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.

H. Ravensworth, York

The Journal replies

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

On “Lean mass is a compartment, not a tissue” — Clinical Trials, 13 Mar 2024

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.

W. Stroud, Chattanooga, TN

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 “Background rates, and why they matter for attribution” — Pharmacology, 12 Mar 2024

You note that symptom burden does not predict weight outcome. This is the single most useful sentence I have read about this treatment. I spent four months believing that feeling well meant it was not working and considered increasing my dose on that basis alone.

C. Rautenbach, Pretoria

The Journal replies

The folk model that suffering indexes efficacy is widespread and the published analyses do not support it. It is also actively harmful when it drives escalation, which is why we gave it a line in the closing section rather than burying it in the tables.

On “Background rates, and why they matter for attribution” — Pharmacology, 12 Mar 2024

Your incidence tables are from the licensed products. I use compounded material at a concentration that does not match any pen. Are the figures transferable at all?

R. Whitlam, Adelaide, SA

The Journal replies

The mechanism transfers; the incidence figures transfer only to the extent that your actual exposure matches the trial exposure, which is unknown unless the content has been measured. That is not evasion. It is the reason we argue for peptide content as a standard reported field rather than purity alone.

On “Background rates, and why they matter for attribution” — Pharmacology, 12 Mar 2024

As an anaesthetist I read the perioperative section with interest and one objection. You frame disclosure as the patient obligation. In my experience the failure is more often ours: the pre-assessment questionnaire in my own institution did not include these drugs until eighteen months after the first guidance appeared.

A. Mbeki, Lusaka

The Journal replies

A fair correction and we have amended the text. If the question is not on the form, the absence of an answer is not a patient failure. We would be interested to hear from readers in other institutions about whether their pre-assessment documentation has caught up.

On “Background rates, and why they matter for attribution” — Pharmacology, 12 Mar 2024

The gallbladder section says some of the excess is attributable to weight loss rather than the drug. If the drug causes the weight loss, is that not a distinction without a difference for the person who ends up in theatre?

D. Mazzarella, Catania

The Journal replies

For the individual, largely yes. For the question of whether one molecule is safer than another, or whether the risk would fall on slower loss, the distinction is the whole question. We should have made clear that it is a mechanistic distinction rather than a consoling one.

On “LAL, kinetic chromogenic, recombinant factor C: three ways to the same figure” — The Supply Chain, 12 Mar 2024

I have worked in aseptic fill for nineteen years and your section on media fills understates one thing. The scale is not the hard part. Running the simulation with every intervention the real process contains — every stopper jam, every environmental sample, every gowning break — is the hard part, and a simulation that omits the interventions is theatre with a growth medium in it.

M. Karlsen, Kristiansand

The Journal replies

That is a better statement of the point than ours and we have amended the section to make the interventions explicit. The scale figure without the intervention requirement is exactly the sort of number that gets quoted as reassurance.