October 2024

Discontinuation rates, read honestly

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

Why your endoscopist wants to know about your injection

Holding a dose before a procedure has a kinetic problem: a weekly drug with a seven-day half-life cannot be cleared by skipping…

The mechanism behind the mechanism

The receptor populations that produce satiety and the ones that produce nausea overlap substantially. That is why the ceiling of…

The GLP-1 receptor is not a switch, and retatrutide is not a key

Receptor pharmacology explains more of the clinical picture than the dose does — and almost none of it appears in the material…

Is survodutide better than retatrutide, or differently balanced?

Head-to-head data exists for some of these comparisons and not for others. This piece says which.

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

The central effects are not a bonus. On the current evidence they are the principal mechanism of weight loss.

Escalating onto a rising curve

We work the arithmetic out in full, because it is arithmetic and it is short.

What Janoshik would need in order to certify sterility, and why it does not

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

The degradation product that elutes underneath the parent peak

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

Asparagine, glycine, and the two residues that decide a shelf life

The sequence predicts the failure mode. A methionine predicts oxidation; an asparagine followed by a glycine predicts…

Asparagine, glycine, and the two residues that decide a shelf life

The sequence predicts the failure mode. A methionine predicts oxidation; an asparagine followed by a glycine predicts…

Check the vial, not the box

A document is only as good as the chain that connects it to the material, and most chains here are two or three links longer…

What a split-sample exercise can establish, and what it cannot

Duplicate submissions under different names test within-laboratory repeatability, which is a different quantity from…

What the four services actually offer, test by test

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

What we would need to randomise to answer this properly

One randomised trial has combined a GLP-1 receptor agonist with supervised exercise. Its result is the single most useful piece…

What SURPASS-4 tells us about maintenance, and what it does not

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

Why the bone question is harder than the muscle question

Density is a proxy for strength and an imperfect one, particularly when soft-tissue thickness over the measurement site is…

Bone density during rapid weight loss: what is known, which is less than you would hope

The evidence base is one secondary analysis, several small studies and a large amount of extrapolation from bariatric surgery.

Weight regain is not a failure of willpower and it is not a mystery

The variance around the mean regain trajectory is large and unexplained, exactly as it is for the weight loss.

The withdrawal trials, read as designs rather than warnings

Three randomised withdrawal designs have tested what happens when treatment stops. Their results are consistent and they are…

What we would need to randomise to answer this properly

The recommendation survives scrutiny. The reasoning offered for it frequently does not.

Repackaging, subdivision, and the batch number that changed hands

A document is only as good as the chain that connects it to the material, and most chains here are two or three links longer…

The retest date and the expiry date are not the same document

A stability programme needs a protocol, defined conditions, a stability-indicating method and time. Time is the ingredient no…

The shelf life ends when the diluent goes in

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

How a release document is put together in a regulated plant

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

The badge economy, and what it is actually certifying

Every step between the laboratory report and the product page removes information, and the badge is the last step.

D-amino acids are invisible to mass spectrometry, and that is the whole problem

Stereochemical inversion changes the molecule, changes its biology, and changes its mass by exactly nothing.

Six words a verification badge would need to mean anything

Every step between the laboratory report and the product page removes information, and the badge is the last step.

Repackaging, subdivision, and the batch number that changed hands

The interval between manufacture and analysis is the most under-read figure on the page, and the one most likely to matter by…

What the trials counted as intolerance

We set out the questions that distinguish a symptom to manage from a dose to change.

A needle is a single-use instrument

For licensed products the in-use period is established by stability data. For a peptide reconstituted at home there is no such…

The dose that got you here and the dose that keeps you here

The commonest real-world strategy in this drug class is the least studied one.

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

The rule that a quarter of weight lost is lean tissue has been in textbooks for decades and does not survive close reading.

The out-of-range flag is a statistical convention with a printer attached

A flag is a probability statement about a population. It is not a statement about the person holding the printout.

A few hundred participants carry the whole body-composition argument

What was pre-specified, what was exploratory, and what was calculated afterwards by people who did not run the trial.

The dose that got you here and the dose that keeps you here

Every withdrawal trial compared full dose against nothing. The clinically interesting comparison — full dose against a reduced…

The one randomised trial that combined an incretin with supervised exercise

One randomised trial has combined a GLP-1 receptor agonist with supervised exercise. Its result is the single most useful piece…

Side effects, cost, supply, target: four reasons with four trajectories

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

The dose that got you here and the dose that keeps you here

The commonest real-world strategy in this drug class is the least studied one.

What a laboratory knows about the material it receives

What a laboratory can and cannot know about the provenance, storage history and representativeness of what lands on its bench.

Randomised withdrawal is the cleanest design in this field and the least discussed

The regain trajectories, arm by arm, with the estimands named.

What a split-sample exercise can establish, and what it cannot

Duplicate submissions under different names test within-laboratory repeatability, which is a different quantity from…

A tested vial is evidence about a vial

Every third-party report in this market describes a sample somebody chose to send. That choice is outside the laboratory’s…

Sending the same vial twice, under two names

Two years ago we ran an anonymised version of this comparison and promised a named one. This is it, with every method printed in…

Side effects, cost, supply, target: four reasons with four trajectories

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

The retest date and the expiry date are not the same document

We asked twenty companies three questions about stability data and print every answer, refusal and non-response.

Two sessions a week, and the evidence behind the prescription

The recommendation survives scrutiny. The reasoning offered for it frequently does not.

What a mass spectrometer does to a peptide before it measures anything

A brief and unromantic tour of the interface between a liquid sample and a vacuum.

Mapping a rotation that you will actually follow

Repeated injection into the same small area produces lipohypertrophy — thickened, rubbery subcutaneous tissue with blunted and…

A part per million, in context

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

What Medutest can tell you about a vial by weighing its water

Water is a reactant in hydrolysis, a plasticiser that mobilises the amorphous matrix, and a carrier for everything else. All…

The certificate is silent on contamination, and it never claimed otherwise

Every certificate circulating in this market answers a question about molecules. Almost none answers a question about organisms,…

Set the threshold at a tenth of a per cent and the small impurities vanish

Baseline placement under a tailing peak is a judgement call with a direct effect on the area. It is one of the few places where…

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

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

GIP was a failed target for thirty years. Then it was not.

The glucagon arm raises energy expenditure and also raises hepatic glucose output. Balancing those is the whole engineering…

A supply gap is a pharmacological event

One omitted dose is a labelling question. Four omitted doses is a clinical one. The two are routinely conflated.

The label says four weeks. The clinic says whatever holds.

The published ladder exists because a protocol needed a single number. Practice has never followed it exactly, and the…

Discontinuation rates, read honestly

Trial discontinuation figures are a floor, not an estimate: trial populations are supported in ways ordinary patients are not.

Reading a barrel in the wrong increments

Almost every case involves a change — a new vial, a new syringe size, a new supplier — carried forward with an old number.

Hydration, protein and the two failures that compound each other

Almost nothing in the standard management repertoire has been tested in a randomised trial in this specific population. We say…