December 2024

Non-responders, and the honest state of the evidence about them

The mechanism is well described. The variance is not.

Three weeks off is a fresh start, whether or not you want one

Concentrations fall by half a week, so a month away leaves a small fraction of steady state. Resuming at the previous dose…

Antiemetics, laxatives and the thin literature underneath them

Constipation is the most tractable of the effects and the most consistently under-managed.

The limits of mechanism: why receptor data will not tell you who responds

A catalogue of open questions, with an assessment of how likely each is to be resolved.

Why a drug that acts on the pancreas changes what food tastes like

A tour of the tissues where the receptor is expressed, and what happens in each.

Severity grading, and the gap between a grade and an experience

Almost every figure in circulation about tolerability comes from six publications. This is what they say.

Reflux, early satiety, and the volume the stomach will accept

The clinical effect profile is almost fully predictable from where the receptor is expressed, which is unusual and useful.

The pyrogen question has a price, and it is not the price of a purity run

Endotoxin is the more tractable of the two questions, and a kinetic chromogenic determination is neither slow nor exotic. It is…

Oxidation, and the peroxide that came in with the surfactant

An isoaspartate rearrangement changes the molecule and not the mass. A method that confirms identity by molecular weight alone…

Benzyl alcohol is a preservative, not a sterilising agent

We set out what is known, what is inferred and what is simply assumed about the fortnight after a vial is opened.

Reading a certificate as a document rather than as a score

The header identifies the batch, the table records the tests, and the footer says who is answerable. Two of the three are…

How a claim degrades between the bench and the listing

What a verification mark would have to carry to be checkable: a date, a lot, a method, a submitter and a link to the report.

We asked four laboratories for a sterility test. Here is what came back.

The absence of microbiological capability in this market is a commercial fact with a straightforward explanation, and it is…

Benzyl alcohol is a preservative, not a sterilising agent

At low concentrations a measurable fraction of peptide can adsorb to glass and plastic surfaces, and the loss is largest exactly…

Why TFC can be entirely straightforward and still tell you nothing about bioburden

The Journal has read several hundred certificates from twenty companies. We set out what the documents actually cover, and what…

Why "muscle-sparing" is a marketing term and not a measurement

Almost every practical recommendation in circulation was established in a population that does not resemble the people now…

Why people actually stop, in the order they actually stop

Real-world persistence figures, with their definitions stated, because the definitions are doing most of the work.

Least significant change: the number your body-composition printout omits

The compartment called lean mass contains water, glycogen, viscera and skin. Only some of it is the tissue anybody is worried…

Every fortnight, every third week, seasonally: an unstudied practice

A great deal of practice has grown up around intermittent schedules. The randomised evidence for any of them is, as far as the…

Eating enough protein on a suppressed appetite is an arithmetic problem before it is a nutritional one

The resistance-training and energy-deficit literature supports a higher protein intake. None of it was conducted in people…

The hormonal adaptations persist for years. That is the mechanism.

The physiology of regain was described a decade before these drugs, and it explains the trajectory without invoking anything…

Maintenance dosing: what is licensed, what is practised, and what is evidenced

Dose reduction is not withdrawal, and the trials that tested withdrawal cannot be read as testing it.

EGFR, cystatin C, and the check on the check

Estimated glomerular filtration rate is a calculation with muscle mass in the denominator of its assumptions. In this population…

Why FGP can be entirely straightforward and still tell you nothing about bioburden

The Journal has read several hundred certificates from twenty companies. We set out what the documents actually cover, and what…

Why a dead-clean sterile filter can pass pyrogen straight through

The limit for a parenteral product is calculable from the dose and the body weight in two lines. Almost nobody in this trade…

Freezing a reconstituted vial: the ice-water interface problem

An in-use period is established by a dedicated study on a specific formulation in a specific container at a specific…

Electrospray, MALDI, and the choice that shapes every spectrum after it

The two ionisation techniques in general use produce different charge distributions, different adducts and different failure…

The degradation product that elutes underneath the parent peak

Reversed-phase chromatography runs in an organic, acidic mobile phase that dissociates most non-covalent aggregates on the way…

The badge is about a sample. The listing is about a product.

Lot-level verification with a public report is a real and achievable thing. It exists in this market, on a minority of listings.

One vial, four weeks, and the data that does not exist

Every degradation pathway accelerates by orders of magnitude on reconstitution, because the solvent that lyophilisation removed…

How far back does this document actually reach?

What happens to traceability when bulk material is subdivided, repackaged and relabelled two or three times before sale.

Gallstones during rapid weight loss: drug, or weight loss?

We give background rates alongside trial rates, because an event occurring during treatment is not thereby caused by it.

Load, not cardio: the distinction the general advice keeps losing

The older-adult diet-and-exercise trials are the closest analogue to rapid pharmacological weight loss, and they are twenty…

Rapid weight loss moves eight analytes for reasons that have nothing to do with the drug

Three different explanations for the same abnormal number, and how to tell them apart.

The visceral fat result nobody quotes, from the substudy everybody cites

The trials measured mass. Nobody measured whether the participants got weaker.

The shortage years, and what they taught about interruption

Cost is the modal reason for discontinuation in every dataset we have seen, and it is absent from the clinical literature.

The supply gap as a clinical event

The trials studied planned withdrawal. Almost nobody stops that way.

In-use periods, and the ones nobody can give you

Sharps disposal is a legal obligation in most jurisdictions and a safety obligation everywhere. Household waste is not a route.

Dose-limiting: a definition worth being strict about

Roughly four to seven per cent of trial participants discontinued for adverse events, mostly gastrointestinal, mostly during…

Two-thirds back: the extension nobody expected to be the headline

A withdrawal trial answers a narrower question than it appears to. This piece states which question.

The badge economy, and what it is actually certifying

What a verification mark would have to carry to be checkable: a date, a lot, a method, a submitter and a link to the report.

Maintenance dosing: what is licensed, what is practised, and what is evidenced

Dose reduction is not withdrawal, and the trials that tested withdrawal cannot be read as testing it.

The lead-in, the randomisation, and the year that followed

A withdrawal trial answers a narrower question than it appears to. This piece states which question.

We split six vials four ways and posted them

The Journal submitted split samples from single lots to three assay services, under names unconnected to this publication, and…

A tested vial is evidence about a vial

A result on one vial generalises to a batch only if the vial was drawn in a way that makes it representative — and nobody…

The lowest effective dose is a real concept with almost no data behind it

A survey of the maintenance evidence, which is shorter than the survey of the withdrawal evidence.

The arithmetic behind every identity confirmation, worked in full

A peptide has a monoisotopic mass and an average mass, they differ by several daltons at this molecular size, and a certificate…

The specification sheet says 500,000. The report says conforms.

Every instrument specification quoted in an advertisement is a best case obtained on a calibration mixture, not on a submitted…

HbA1c and its lag: what a result three months old is telling you

What the SURPASS and STEP programmes reported, with the estimands and the baseline values stated.

Errors ranked by how much dose they move

A pharmacist catches most of these in licensed practice. In this market there is no pharmacist, so the checks have to be…

A reference interval is not a target, and a result outside one is not a diagnosis

The arithmetic of the reference change value, worked for the analytes that matter here.

A guide to the results that will resolve themselves

The panel drawn during a week of vomiting is measuring the vomiting.

What changed after we published the first version of this

A reader holding a certificate can work out what it does not cover in about ninety seconds, and that is a useful ninety seconds.

What we would need to measure to explain the response distribution

The mechanism is well described. The variance is not.

Reading a certificate for what it does not say

The most consequential features of most certificates in this market are the tests that do not appear on them at all.

One method is one opinion

An orthogonal method separates on a different physical principle, so that species co-eluting in the first are likely to resolve…

What changing your injection day does to tirzepatide exposure, and what it does not

What the pharmacokinetic data supports about dose timing, missed doses and interruption.

The kidney, the heart and the receptor nobody was looking for

The same receptor population that produces the therapeutic effect produces the commonest adverse one.

Albumin, fatty-acid chains, and the engineering that made a weekly incretin possible

An accumulation model, drawn from published parameters, with its assumptions stated.

Choosing a needle for a subcutaneous peptide

Gauge affects pain and flow rate rather than depth. A finer needle is more comfortable and slower, and with a viscous solution…