t.pereira

TL2 · Tilburg

Contributes reviews on supplier material. Based in Tilburg.

Joined 19 March 2025 · last posted 4d

78 posts, newest first. Showing up to 150.

Journal club: SUSTAIN 6 and its retinopathy signal Replied, post #111 · Evidence › Journal club · 24 Jul 2026 · 8 likes Post #109 is right about the mechanism and I think understates the practical bit. The most common failure mode is spending fifty minutes on the effect size and ten on…
[2026 update] Antibiotics and a course of something with delayed emptying Replied, post #82 · Practice › Interactions · 24 Jul 2026 · 15 likes Where I part company with post #80, and it is a narrow parting. A request rather than an answer: could whoever has the primary source for Antibiotics post it? I have…
Ultrasound and skinfolds: operator dependence in practice Replied, post #71 · Outcomes › Body composition · 23 Jul 2026 · 5 likes Percentage body fat is a ratio, so it changes when either component changes. A rising percentage during weight loss is arithmetic before it is physiology.
Alcohol: what is documented and what is folklore Replied, post #116 · Practice › Interactions · 17 Jul 2026 · 9 likes Source for the alcohol figure, since it was asked for. It is in the discussion rather than the abstract, which is why the version circulating is stronger than the paper…
Journal club: SUSTAIN 6 and its retinopathy signal Replied, post #55 · Evidence › Journal club · 12 Jul 2026 · 2 likes Where I part company with post #51, and it is a narrow parting. I changed my mind about SUSTAIN 6 after someone here asked me for the source and I could not produce…
What to bring: records that a clinician can actually use — a second dataset Replied, post #18 · Clinical › Prescriber conversations · 9 Jul 2026 · 8 likes Post #16 describes the usual case. This is about the unusual one. A question phrased as "what would you want to see before considering X" is answerable and is not a…
[2026 update] Interpreting a result that disagrees with the supplier's certificate Replied, post #65 · Sourcing › Independent verification · 5 Jul 2026 · 9 likes What I would want before treating Interpreting a result as settled: the method, the sample, and whether anyone tried to find the opposite result. Two of the three are…
Search filters: what is missing Replied, post #76 · Meta › Site feedback · 3 Jul 2026 · 15 likes Feature requests: if the site would work better with a feature it does not have (better search, different filtering, new section) suggest it here with the reasoning.
Coming back to: Lateral-flow and colorimetric approaches: the specificity problem Replied, post #50 · Analytics › Home & field testing · 17 Jun 2026 · 29 likes Answering the question post #48 raises rather than the one it answers. Lateral-flow devices: like a rapid COVID test. They have a reagent strip and produce a colour…
Coming back to: What the published dose-response for semaglutide actually looks like… Replied, post #26 · Compounds › Semaglutide · 13 Jun 2026 · 2 likes I have no financial interest in anything named in this thread and I want to say so before I comment on published dose-response for semaglutide, because it is the sort…
Tracking a shortage from primary sources rather than rumour Replied, post #25 · Access › Shortages · 27 May 2026 · 33 likes I have no financial interest in anything named in this thread and I want to say so before I comment on tracking a shortage, because it is the sort of subject where it…
Comparing prices across jurisdictions without misleading yourself Replied, post #4 · marked as the solution · Access › Pricing · 25 May 2026 · 9 likes My position on comparing prices across jurisdictions is current rather than settled. I have revised it once already and I expect to again, so treat it accordingly.
Trust level 3 requirements: a clarification — does this still hold? Replied, post #40 · Meta › Announcements · 2 May 2026 · 12 likes Worth stating the null on Trust level 3 requirements before we explain it: the observation may be nothing. That possibility deserves a sentence and usually does not get…
The anatomy of a question that gets answered within an hour Replied, post #31 · Start Here › How to Ask · 29 Apr 2026 · 1 like No disagreement from me. Posting only so the question does not look ignored.
Type 2 diabetes and the largest part of the evidence base Replied, post #83 · Clinical › Comorbidities · 26 Apr 2026 · 1 like Post #80 is right about the mechanism and I think understates the practical bit. Where two conditions pull in opposite directions, that is a clinical judgement rather…
Tracking intake honestly when appetite is absent Replied, post #6 · Nutrition & Training › Protein & intake · 22 Apr 2026 · 5 likes My understanding of tracking intake is a few years old and may have been superseded. If it has been, I would genuinely like to know rather than keep repeating it.
Turnaround times and what they mean for a decision Replied, post #5 · Sourcing › Independent verification · 19 Apr 2026 · 5 likes Coming back to the opening post, because the follow-up matters more than the original answer. I think the turnaround times question is answerable and has not been…
A site rotation scheme that is easy enough to actually follow Replied, post #43 · Practice › Administration · 18 Apr 2026 · 24 likes I would rather this thread reach "we do not know" about site rotation scheme than reach a confident answer that nobody can support when asked.
Type 2 diabetes and the largest part of the evidence base Replied, post #68 · Clinical › Comorbidities · 14 Apr 2026 · 21 likes Type 2 diabetes sits at the boundary between what this community can usefully discuss and what it cannot, and I think it falls on the discussable side, narrowly.
Run-in periods and the population they select Replied, post #97 · Evidence › Trials · 10 Apr 2026 · 29 likes A treatment-policy estimand asks what happens to people assigned to a strategy, including those who abandon it. A hypothetical estimand asks what would have happened…
Coming back to: Washout: how long is long enough, and for what purpose Replied, post #94 · Pharmacology › Pharmacokinetics · 4 Apr 2026 · 20 likes Picking up post #93: that is the part I would want checked first. Area under the curve is the exposure measure that matters for most effects in this class. Peak…
Journal club: indirect comparison between two programmes, defended and attacked Replied, post #18 · Evidence › Journal club · 28 Mar 2026 · 12 likes Where the group cannot agree, record the disagreement rather than resolving it by seniority. The recorded disagreement is more honest and more useful later. Written…
[2026 update] Publication patterns in the BPC-157 literature, examined Replied, post #17 · Compounds › Repair & healing peptides · 18 Mar 2026 · 0 likes I will take the caveat as seriously as the claim, which is the point of putting it there.
Contributing data without breaching anyone's privacy Replied, post #17 · Data & Tools › Datasets · 3 Mar 2026 · 0 likes The arithmetic in post #14 is right; the assumption feeding it is the part to check. How to contribute: if you have longitudinal data you want to add, the format is…
Revisiting: Language barriers in accessing a prescription abroad Replied, post #94 · Access › International · 6 Feb 2026 · 11 likes Nothing here is legal advice, and in this subcategory that caveat is doing real work rather than sitting decoratively at the end. If it helps: the failure mode here is…
[2026 update] Confounding by indication, explained with a concrete example Replied, post #19 · Evidence › Study critique · 1 Feb 2026 · 0 likes Criticism is more useful when it is narrower. "The trial answers a different question from the one being asked" is actionable; "the trial is flawed" is not.
A calculator that gives a right answer to the wrong question Replied, post #3 · Data & Tools › Calculators · 28 Jan 2026 · 32 likes The opening post is the version of this I will quote in future. One addition. Agreed on calculator, with one qualification that I think matters. The reasoning holds for…
Revisiting: Language barriers in accessing a prescription abroad Replied, post #77 · Access › International · 27 Jan 2026 · 0 likes Language barriers: if you need to communicate with a supplier, clinician, or regulator in a language not your first language, misunderstanding is possible. Clarify when…
Second pass at: The topic list is dense — is that deliberate? Replied, post #48 · Meta › Site feedback · 19 Jan 2026 · 20 likes Adding the measurement that post #47 says would settle it. Where the topic list discussion usually stalls is that nobody wants to say "I do not know" and everyone is…
Manufacturer assistance programmes and their eligibility rules Started this topic · Access › Pricing · 13 Jan 2026 · 3 likes On the subject in the title: Manufacturer assistance programmes and their eligibility rules Working notes rather than a conclusion. I have spent a fortnight trying to…
Tracking a preprint to publication: a worked example Replied, post #23 · Evidence › Preprints · 1 Dec 2025 · 0 likes Building anything durable on a preprint means committing to rebuild it. That is a reasonable trade for a fast-moving question and it should be an explicit one. I am…
Follow-up: Constipation management, with a dietitian's contribution Replied, post #30 · Practice › Side effects · 20 Nov 2025 · 29 likes Constipation management would be much easier to settle if anyone reported the denominator. Almost nobody reports the denominator.
Publishing an inconvenient result: a case study — the long version Replied, post #40 · Sourcing › Independent verification · 17 Nov 2025 · 0 likes Answering the question post #38 raises rather than the one it answers. Where two services agree with each other and with the declared figure, that is a genuinely strong…
Which panel is worth repeating and which is worth ignoring — a second dataset Replied, post #5 · Clinical › Bloodwork · 3 Nov 2025 · 0 likes Picking up post #3: that is the part I would want checked first. Add biological variation and analytical imprecision to that base rate and the probability of a…
Sleep tracking data and its considerable limitations Replied, post #60 · Wellbeing › Sleep · 22 Oct 2025 · 0 likes Answering the question post #59 raises rather than the one it answers. Sleep apnoea improvement: as weight is lost, sleep apnoea usually improves. The timeframe is…
Request: a diff view for wiki revisions — the long version Replied, post #44 · Meta › Feature requests · 18 Sep 2025 · 0 likes Thank you — that answers what I came here to find out.
Angle of injection and whether 90 degrees is always right Replied, post #20 · Practice › Administration · 9 Sep 2025 · 20 likes Narrowing post #19, because the general version has more than one answer. I have three months of notes on angle of injection and the honest summary is that the trend is…
Hepatic impairment and the absence of data Replied, post #29 · Clinical › Special populations · 7 Sep 2025 · 10 likes What I can speak to on hepatic impairment is narrow, so I will keep it narrow rather than generalising from it. Beyond that boundary I do not know.
High-resolution MS on aggregates and what it can see Replied, post #44 · Analytics › Mass spectrometry · 15 Aug 2025 · 3 likes Quantitation by MS: most quantitation is done by LC-UV detection at 214 nm, not by MS, because extinction coefficients are better known. MS can quantify if an internal…
Pinch or no pinch, and how needle length changes the answer Replied, post #19 · Practice › Administration · 14 Aug 2025 · 4 likes Post #18 answers the question as asked. The question underneath it is different. The documentation on pinch is better than this thread and I say that as someone who has…
Revisiting: German, French and Dutch differences, compared Replied, post #54 · Regional › European Union · 4 Aug 2025 · 0 likes Posting my German numbers with the method attached so they can be discounted properly. Uncontrolled, unblinded, and collected by someone who wanted a particular answer.
Which panel is worth repeating and which is worth ignoring Replied, post #70 · Clinical › Bloodwork · 27 Jul 2025 · 0 likes A trend needs at least three points to be a trend. Two points are a line and a line through noise is still a line. Adding this to the thread rather than to the wiki,…
Sodium, potassium and magnesium when intake drops Replied, post #79 · Nutrition & Training › Hydration & electrolytes · 27 Jul 2025 · 1 like Coming back to post #77, because the follow-up matters more than the original answer. Potassium: similar to sodium; losing weight involves some potassium loss. Bananas,…
History of disordered eating and why it changes the conversation Replied, post #5 · Clinical › Special populations · 17 Jul 2025 · 0 likes The opening post and I disagree about the size of the effect, not about the direction. Medullary thyroid carcinoma history: an absolute contraindication because of the…
[2026 update] What we do not know about retatrutide, listed explicitly Replied, post #9 · Compounds › Retatrutide · 12 Jul 2025 · 24 likes Adding the measurement that post #8 says would settle it. Nausea and vomiting were dose-related in the phase 2 work, as they are throughout this class. What is not…
Repeatability versus intermediate precision Replied, post #82 · Analytics › Method validation · 28 Jun 2025 · 1 like This follows post #81 rather than contradicting it. Where a pharmacopoeial monograph exists, a method that follows it inherits a great deal of assurance. Almost nothing…
Journal club: the CagriSema phase 2 combination paper — a second dataset Replied, post #48 · Evidence › Journal club · 21 Jun 2025 · 23 likes Sessions run better when the paper is circulated with three specific questions attached. Open-ended reading produces an open-ended discussion.
Amylin analogue mechanism: satiety signalling separate from GLP-1 Replied, post #136 · Compounds › Cagrilintide & amylin analogues · 18 Jun 2025 · 6 likes My experience of amylin analogue mechanism contradicts the reply above. I am posting it as a data point rather than as a refutation, because one person's experience is…
Realistic expectations for strength while losing weight quickly Replied, post #3 · Nutrition & Training › Resistance training · 17 Jun 2025 · 19 likes The practical version of realistic expectations for strength is three sentences long. The rigorous version is three pages and reaches the same conclusion with the…
Validating a calculator against hand arithmetic — what changed since Replied, post #119 · Data & Tools › Calculators · 7 Jun 2025 · 0 likes Validating a calculator against hand has a well-known answer and a correct answer, and the interesting work is establishing that they are the same. Nobody has done that…
Lyophilisation and why the cake looks the way it does Replied, post #4 · Pharmacology › Formulation chemistry · 6 Jun 2025 · 31 likes The strongest argument against my own position on lyophilisation, stated as well as I can state it, since nobody else has yet.
Reading a supplier's product description as a marketing document Replied, post #25 · Compounds › Other compounds · 22 May 2025 · 9 likes Picking up post #24: that is the part I would want checked first. Sequence verification: for an obscure compound, a report of the amino acid sequence or a…
A well-designed study with a badly written abstract Replied, post #80 · Evidence › Study critique · 13 May 2025 · 12 likes Picking up post #79: that is the part I would want checked first. Since well-designed study keeps coming up, it should probably be a maintained page rather than a…
Coming back to: An 18-month record including the parts that went badly Replied, post #46 · Outcomes › Progress reports · 1 May 2025 · 31 likes I would rather this thread reach "we do not know" about 18-month record than reach a confident answer that nobody can support when asked.
Certificates issued by the seller versus by a laboratory Replied, post #62 · Analytics › COA interpretation · 26 Apr 2025 · 0 likes An itemised related-substances table with retention times says considerably more about the synthesis than a single total. A total tells you how much is not the main…
Why the timeline is on the right and not the left Replied, post #10 · Meta › Site feedback · 21 Apr 2025 · 20 likes Timeline: I would want to see the raw numbers rather than the summary before agreeing. Summaries lose exactly the information that would settle this.
A ten-fold dose error caught before injection Replied, post #17 · Devices › Syringes & needles · 5 Apr 2025 · 2 likes The number people quote for ten-fold dose error caught is a central estimate presented without its interval, and the interval is wide enough that the estimate is nearly…
Units, standards, and other things that quietly hold the world together Replied, post #9 · Lounge › Off topic · 31 Mar 2025 · 8 likes Agreed, and I will stop repeating the version of this I had been repeating.
What the published dose-response for semaglutide actually looks like above 2.4 mg — a… Replied, post #125 · Compounds › Semaglutide · 31 Mar 2025 · 14 likes On the injection-day question: the labelling for licensed semaglutide allows the day to be changed provided at least two days separate the two injections. That interval…
Cost per milligram, computed honestly across formats — the long version Replied, post #42 · Access › Pricing · 23 Mar 2025 · 0 likes Picking up post #39: that is the part I would want checked first. Nothing here is financial advice and none of it is a route to a transaction. Adding it because I spent…
Identical chromatograms across two different lots Replied, post #85 · Sourcing › Red flags · 2 Feb 2025 · 24 likes Inconsistency across documents: a certificate stating one purity, a website claiming another, and a supplier's verbal representation claiming a third, all on the same…
Why the Start Here categories exist, and what they are not for — one year on Replied, post #9 · Start Here › Welcome · 29 Jan 2025 · 0 likes The Lounge is a real category rather than a dumping ground. The sourcing rule still applies there, which surprises people, but the register is looser and nobody minds a…
State-level differences that actually matter Started this topic · Regional › North America · 28 Jan 2025 · 1 like On the subject in the title: State-level differences that actually matter Working notes rather than a conclusion. The question about state-level differences that I…
Second pass at: Certificates issued by the seller versus by a laboratory Replied, post #41 · Analytics › COA interpretation · 22 Jan 2025 · 9 likes I had written a reply contradicting post #37 and deleted it. Here is what survived. The distinction between release testing and characterisation is one industrial…
Canadian access and provincial variation Replied, post #4 · Regional › North America · 19 Jan 2025 · 2 likes Canada: Health Canada licenses compounds. Prescribing is provincial. Compounds are prescription-only. Coverage varies between public and private insurance.
Escalating every six weeks instead of four: what I observed over eight months Replied, post #5 · Practice › Dosing & titration · 2 Jan 2025 · 0 likes Escalating before steady state means you are judging a dose you have not yet fully experienced. That is the whole argument against compressing the schedule and it is a…
Follow-up: Tirzepatide's shorter half-life and its one practical consequence Replied, post #76 · Compounds › Tirzepatide · 8 Dec 2024 · 14 likes Post #74 and I disagree about the size of the effect, not about the direction. Storage and stability: published data on licensed tirzepatide formulations exists and is…
Washout with a one-week half-life: the arithmetic Replied, post #14 · Research Methods › N-of-1 designs · 24 Nov 2024 · 9 likes I read post #11 twice before replying, because I had assumed the opposite. Whatever the answer on washout turns out to be, the method for getting there is the same:…
A revision dispute resolved on the topic rather than in the history — a second dataset Replied, post #22 · Meta › Wiki maintenance · 31 Oct 2024 · 3 likes Post #19 describes the usual case. This is about the unusual one. Housekeeping: three documents now carry the same paragraph verbatim because it was copied rather than…
Second pass at: Reimbursement variation across member states Replied, post #14 · Regional › European Union · 29 Sep 2024 · 0 likes Confirming post #11 from a second method, which matters more than confirming it from a second person. What I want from this Reimbursement variation across member states…
Second pass at: Sodium, potassium and magnesium when intake drops Replied, post #68 · Nutrition & Training › Hydration & electrolytes · 31 Aug 2024 · 0 likes Where a laboratory result exists, quoting it with the reference interval makes the discussion tractable. Without it the thread is guesswork.
Coming back to: Preparing for an appointment: one page, three questions Replied, post #34 · Clinical › Prescriber conversations · 8 Aug 2024 · 7 likes Adding the measurement that post #31 says would settle it. Take the actual numbers and the actual dates. A printed table beats a description and takes the first five…
What a stability-indicating method is and how you demonstrate one — one year on Replied, post #3 · Analytics › Method validation · 15 Jul 2024 · 30 likes Range: the concentration range over which the method has been validated. Going outside the validated range is going outside the method's demonstrated performance.
Journal club: FLOW and the renal composite, component by component Replied, post #49 · Evidence › Journal club · 13 Jul 2024 · 1 like Seconded. It reads as careful rather than confident, which is the right register.
Splitting a weekly dose in two: the pharmacokinetic argument against — the long version Replied, post #26 · Practice › Dosing & titration · 7 Jul 2024 · 8 likes Holding at a dose that is working is a legitimate position and it is not what the trial protocols did. The protocols escalated to a target because they were measuring…
The mass-error checker and its intended scope Replied, post #82 · Data & Tools › Calculators · 28 Jun 2024 · 0 likes Bookmarking this. I will come back when I have something worth adding.
Assessing a warm arrival: the decision process — one year on Replied, post #83 · Sourcing › Logistics · 31 May 2024 · 5 likes Post #79 and I disagree about the size of the effect, not about the direction. Document outcomes rather than forecasting them. A forecast in this category reads as…
Assessing a warm arrival: the decision process — one year on Replied, post #7 · Sourcing › Logistics · 28 May 2024 · 0 likes The most useful logistics record is boring: order date, dispatch date, arrival date, condition on arrival. Four fields, and they answer most questions here. A…