Every letter we have printed
Page 12 of 77 of this archive, newest first.
On “What the survodutide schedule assumes about a person it has never met” — Patient Notes, 19 Feb 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.
— J. Wenninger, Graz
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 “What the trial protocols permitted, and what the labels omitted” — Pharmacology, 17 Feb 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.
— L. Dziedzic, Wrocław
On “What the trial protocols permitted, and what the labels omitted” — Pharmacology, 17 Feb 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.
— E. Beauchamp, Ottawa, ON
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 “What the trial protocols permitted, and what the labels omitted” — Pharmacology, 17 Feb 2026
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?
— H. Ravensworth, York
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 “What the trial protocols permitted, and what the labels omitted” — Pharmacology, 17 Feb 2026
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.
— E. Marchetti, Bologna
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 the trial protocols permitted, and what the labels omitted” — Pharmacology, 17 Feb 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.
— R. Devaney, Ballarat, VIC
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 “What the older diet-and-exercise trials found in the hip” — Laboratory Notebook, 16 Feb 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.
— H. Ravensworth, York
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 adjudicated, and how” — Explainers, 16 Feb 2026
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.
— E. Adamou, Nicosia
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 “What PeptideMeter charges to answer the pyrogen question” — The Supply Chain, 14 Feb 2026
Your table of responses records four declines citing research-use-only status, and you call that a legally sound answer. It is also the answer that ends the conversation. What would you have a supplier say instead?
— D. Chukwuma, Onitsha
Something like: this product is sold for research use, is not represented as a sterile injectable, and here is what we nonetheless do — aseptic fill in a classified environment, bioburden to a stated specification, post-use filter integrity testing. Three of our correspondents said close to that. It concedes nothing legally and tells a reader a great deal.
On “What PeptideMeter charges to answer the pyrogen question” — The Supply Chain, 14 Feb 2026
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. Sandhu, Amritsar
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.
On “What PeptideMeter charges to answer the pyrogen question” — The Supply Chain, 14 Feb 2026
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".
— A. Basaraba, Winnipeg, MB
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.
On “The badge is about a sample. The listing is about a product.” — Analytics, 14 Feb 2026
On the archive point: a public record of submissions by vendor would be gamed within a month. Vendors would submit under the names of resellers, or through intermediaries, and the archive would show a distribution as selected as the current one but with a veneer of completeness.
— Y. Sasaki, Sapporo
Probably true in part, and it is the strongest argument against our proposal. Our answer is that gaming requires effort and leaves traces, which the present arrangement does not, and that a partially gamed record is more informative than no record. We would not claim more than that.
On “The badge is about a sample. The listing is about a product.” — Analytics, 14 Feb 2026
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.
— M. Tsvangirai, Bulawayo
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 “The badge is about a sample. The listing is about a product.” — Analytics, 14 Feb 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.
— D. Lockridge, Tulsa, OK
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 “The badge is about a sample. The listing is about a product.” — Analytics, 14 Feb 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.
— T. Wexford, Louisville, KY
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 badge is about a sample. The listing is about a product.” — Analytics, 14 Feb 2026
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.
— R. Cadogan, Bridgetown
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 “Vitamin D, adiposity, and a volume-of-distribution problem” — Clinical Trials, 13 Feb 2026
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.
— A. Petrucci, Bari
On “Vitamin D, adiposity, and a volume-of-distribution problem” — Clinical Trials, 13 Feb 2026
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?
— D. Ferreira-Lopes, Porto
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 “Vitamin D, adiposity, and a volume-of-distribution problem” — Clinical Trials, 13 Feb 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?
— F. Aubert, Toulouse
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 “Vitamin D, adiposity, and a volume-of-distribution problem” — Clinical Trials, 13 Feb 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.
— B. Ademola, Ilorin
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 “Vitamin D, adiposity, and a volume-of-distribution problem” — Clinical Trials, 13 Feb 2026
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.
— D. Chukwuma, Onitsha
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 “Reading the receptor: what distinguishes survodutide from liraglutide at the…” — Explainers, 12 Feb 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.
— P. Ekundayo, Akure
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 “Reading the receptor: what distinguishes survodutide from liraglutide at the…” — Explainers, 12 Feb 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?
— J. Wenninger, Graz
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 “Reading the receptor: what distinguishes survodutide from liraglutide at the…” — Explainers, 12 Feb 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. Fournier, Nantes
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 “Holding a dose is a decision, not a failure” — Pharmacology, 12 Feb 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.
— K. Sivertsen, Bergen
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 “Holding a dose is a decision, not a failure” — Pharmacology, 12 Feb 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.
— J. Vasilenko, Chisinau
On “The shortage years, and what they taught about interruption” — The Ledger, 11 Feb 2026
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?
— A. Nazarian, Glendale, CA
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 “The shortage years, and what they taught about interruption” — The Ledger, 11 Feb 2026
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.
— M. Fitzhenry, Cork
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 “The shortage years, and what they taught about interruption” — The Ledger, 11 Feb 2026
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.
— D. Iversen, Aalborg
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 shortage years, and what they taught about interruption” — The Ledger, 11 Feb 2026
Your piece describes tapering as pharmacologically pointless and then spends three paragraphs making a case for it. Pick one.
— G. Escalante, Lima
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 “Monitoring intervals, and the case against measuring too often” — Laboratory Notebook, 11 Feb 2026
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. Tejeda, Santo Domingo
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 “Monitoring intervals, and the case against measuring too often” — Laboratory Notebook, 11 Feb 2026
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.
— B. Wojciechowski, Kraków
On “Monitoring intervals, and the case against measuring too often” — Laboratory Notebook, 11 Feb 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.
— W. Stroud, Chattanooga, TN
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 “The brainstem does most of the work” — Pharmacology, 8 Feb 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.
— G. Thorbjørnsen, Tromsø
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 brainstem does most of the work” — Pharmacology, 8 Feb 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.
— C. Tremonti, Palermo
Fair, and now stated in the text.
On “The brainstem does most of the work” — Pharmacology, 8 Feb 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.
— H. Steinmetz, Basel
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 “The brainstem does most of the work” — Pharmacology, 8 Feb 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?
— E. Sørheim, Stavanger
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 “The brainstem does most of the work” — Pharmacology, 8 Feb 2026
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.
— N. Zangwill, Manchester
Correct, and the table now carries that caveat. The ratio is unaffected by a constant bioavailability factor, but the absolute concentrations obviously are.
On “Reading the survodutide titration schedule as a regulatory artefact” — Explainers, 7 Feb 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.
— K. Sivertsen, Bergen
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 survodutide titration schedule as a regulatory artefact” — Explainers, 7 Feb 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.
— J. Vasilenko, Chisinau