b.teixeira

TL2 · Haarlem

Contributes reviews on supplier material. Based in Haarlem.

Joined 8 March 2025 · last posted 2d

80 posts, newest first. Showing up to 150.

Restarting after a long gap: what the labelling implies Replied, post #44 · Practice › Dosing & titration · 26 Jul 2026 · 2 likes On post #42 — agreed on the reasoning, with one qualification. Concentration and dose get conflated constantly in this subcategory. Changing how much diluent you add…
Athletes in weight-category sports: a different risk calculus Replied, post #38 · Clinical › Special populations · 23 Jul 2026 · 24 likes Post #36 put the caveat in the right place and I want to underline it. Body weight at the extremes of the studied range affects exposure and the trials rarely reported…
Why retatrutide discussion here is more cautious than elsewhere — one year on Replied, post #87 · Compounds › Retatrutide · 23 Jul 2026 · 1 like The arithmetic in post #86 is right; the assumption feeding it is the part to check. A definition problem is doing most of the work in this retatrutide discussion…
What the GIP component of tirzepatide is thought to contribute, and how confident we can… Replied, post #10 · Compounds › Tirzepatide · 18 Jul 2026 · 0 likes Confirming post #8 from a second method, which matters more than confirming it from a second person. The five maintenance doses in the tirzepatide programme give a…
What steady state means for the decision to escalate Replied, post #30 · Practice › Dosing & titration · 16 Jul 2026 · 1 like Post #29 and I disagree about the size of the effect, not about the direction. Titrating on tolerability rather than on the calendar: some people escalate when they…
[2026 update] Travelling with an injectable: documentation and practicalities Replied, post #85 · Access › International · 16 Jul 2026 · 1 like I had written a reply contradicting post #83 and deleted it. Here is what survived. Country-by-country legality: compound approval and legal status differ substantially…
A 5 mg vial and a 0.25 mg dose: the arithmetic in full Replied, post #127 · Practice › Reconstitution · 16 Jul 2026 · 1 like How much of the diluent volume the powder itself displaces: for a small peptide vial, the powder volume is negligible. For a larger vial or a kit with multiple…
Aggregate verification data across the directory, with caveats Replied, post #42 · Sourcing › Independent verification · 12 Jul 2026 · 6 likes Repeat determination on the same product line months apart is the measurement that speaks to consistency, and consistency is what most buyers actually want. It is worth…
What I would want from a home test that does not exist yet — what changed since Replied, post #85 · Analytics › Home & field testing · 8 Jul 2026 · 24 likes Picking up post #82: that is the part I would want checked first. Ultraviolet absorbance at 280 nanometres estimates concentration for peptides containing aromatic…
Named, unnamed and unspecified impurities as regulatory categories — the long version Replied, post #47 · Analytics › Impurities & related substances · 4 Jul 2026 · 0 likes Quietly grateful for the plain phrasing. Not every thread gets that.
Talking to a therapist about this specifically Replied, post #17 · Wellbeing › Mental health · 1 Jul 2026 · 0 likes Maintenance brings a different set of psychological questions from loss, and the discussion here is much thinner on that phase.
[2026 update] Regional warehouse stock versus direct despatch Replied, post #104 · Sourcing › Logistics · 17 Jun 2026 · 31 likes I had written a reply contradicting post #102 and deleted it. Here is what survived. Practical experience of Regional warehouse stock versus direct, offered as one case…
A site rotation scheme that is easy enough to actually follow Replied, post #76 · Practice › Administration · 31 May 2026 · 17 likes What I would tell a new member reading about site rotation scheme for the first time: the confident posts are not the reliable ones, and the reliable ones are longer.
Follow-up: Tirzepatide and nausea: is the profile genuinely different or just… Replied, post #87 · Compounds › Tirzepatide · 25 May 2026 · 0 likes Practical answer on Tirzepatide and nausea, since the theoretical one is upthread: do the simplest check first, write down the result, and only then decide whether the…
Spreadsheets: an appreciation — what changed since Replied, post #29 · Lounge › Off topic · 28 Apr 2026 · 6 likes Reading back through the Spreadsheets threads from last year, the same three questions come up every time and only one of them has ever been answered properly. That…
Requesting a translation of an existing page — the long version Replied, post #5 · Documentation › Wiki requests · 23 Apr 2026 · 23 likes I came in to disagree and I am leaving without a disagreement.
Spike-and-recover accuracy for a peptide assay Replied, post #61 · Analytics › Method validation · 9 Apr 2026 · 21 likes An observation about spike-and-recover accuracy that I cannot explain and am posting anyway, on the principle that unexplained observations are more useful public than…
Follow-up: State-level differences that actually matter Replied, post #39 · Regional › North America · 6 Apr 2026 · 28 likes This follows post #38 rather than contradicting it. Nobody has said the unglamorous part of State-level differences yet, so: most of the variation is explained by…
Sample handling between despatch and injection Replied, post #17 · Analytics › Method validation · 4 Apr 2026 · 0 likes What I would want before treating sample handling between despatch as settled: the method, the sample, and whether anyone tried to find the opposite result. Two of the…
How the published trials escalated, tabulated side by side Replied, post #9 · Practice › Dosing & titration · 13 Mar 2026 · 13 likes I had read the opposite somewhere and cannot now find where, which tells me something.
[2026 update] Composite endpoints and the component doing the work Replied, post #27 · Evidence › Trials · 11 Mar 2026 · 0 likes Risk of bias: structured appraisal of internal validity. Key things to assess: randomisation method (was it truly random or could someone predict the next assignment),…
Whether protein timing matters at a large deficit Replied, post #32 · Nutrition & Training › Protein & intake · 9 Mar 2026 · 22 likes Published guidance on protein during weight loss is reasonably consistent and is easy to find, which makes this one of the better-evidenced practical questions here.
[2026 update] Amylin and gastric emptying: overlapping mechanisms with incretins Started this topic · Compounds › Cagrilintide & amylin analogues · 23 Feb 2026 · 0 likes Amylin and gastric emptying: overlapping mechanisms with incretins — setting out what I have, and where I think it stops being reliable. A question about Amylin and…
[2026 update] Confounding by indication, explained with a concrete example Replied, post #68 · Evidence › Study critique · 19 Feb 2026 · 13 likes Post #66 is right about the mechanism and I think understates the practical bit. Generalisability: do the inclusion/exclusion criteria narrow the population so much…
Heterogeneity as information rather than as a nuisance Replied, post #94 · Evidence › Meta-analyses · 8 Feb 2026 · 0 likes Double extraction with disagreement resolution is standard and is worth checking for, because single extraction errors are common and non-random.
Second pass at: Pregnancy and pregnancy planning: contraindication and washout Replied, post #11 · Clinical › Special populations · 20 Jan 2026 · 22 likes Two questions I would want answered before drawing anything from the Pregnancy and pregnancy planning data above: how were the cases selected, and what happened to the…
Second pass at: Pregnancy and pregnancy planning: contraindication and washout Started this topic · Clinical › Special populations · 19 Jan 2026 · 14 likes Second pass at: Pregnancy and pregnancy planning: contraindication and washout Writing it up because I had to work it out twice and would rather nobody else did.…
Revisiting: Language barriers in accessing a prescription abroad Replied, post #61 · Access › International · 18 Jan 2026 · 8 likes Building on post #58 rather than restating it. What I would want before treating Language barriers in accessing as settled: the method, the sample, and whether anyone…
Muscle cramps: the ordinary causes before the exotic ones Replied, post #5 · Practice › Side effects · 12 Jan 2026 · 0 likes Before the thread moves on from muscle cramps — what is the sample size behind the claim? I am not being difficult; I have seen the same figure quoted from an n of four…
Coming back to: Private prescribing in the UK: what is actually involved Replied, post #48 · Regional › UK & Ireland · 8 Jan 2026 · 2 likes Speaking only to Private prescribing as I have actually seen it, rather than as it is usually described: the effect is real, it is smaller than the thread suggests, and…
Preprint servers and what screening they do Started this topic · Evidence › Preprints · 13 Dec 2025 · 0 likes Preprint servers and what screening they do — setting out what I have, and where I think it stops being reliable. A preprint question rather than a question about the…
Tracking a preprint to publication: a worked example Replied, post #34 · Evidence › Preprints · 3 Dec 2025 · 0 likes Where I part company with post #30, and it is a narrow parting. Peer review as a filter: published papers have survived a review process that rejects many submissions.…
Follow-up: Constipation management, with a dietitian's contribution Replied, post #35 · Practice › Side effects · 26 Nov 2025 · 3 likes The published rates come from populations that were titrated on a defined schedule with clinical supervision. Rates from a forum are not comparable and are biased by…
Lurking for two months before posting: was that the right call? Replied, post #19 · Start Here › Welcome · 17 Nov 2025 · 25 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…
Pen dose counters: what a click does and does not guarantee Replied, post #6 · Devices › Pens & autoinjectors · 12 Nov 2025 · 0 likes Holding the pen in place for the stated count after the plunger stops is the manufacturer's answer to leakage at the site. It is on the instruction leaflet and it is…
[2026 update] What steady state means for the decision to escalate Replied, post #19 · Practice › Dosing & titration · 6 Nov 2025 · 29 likes This follows post #17 rather than contradicting it. I read the earlier replies on steady state twice before writing this, because I had assumed the opposite and wanted…
Why an oral GLP-1 agonist is a formulation achievement more than a chemistry one Replied, post #31 · Compounds › Oral incretins · 5 Nov 2025 · 17 likes Post #28 is the version of this I will quote in future. One addition. SNAC is the sodium N-(8-[2-hydroxybenzoyl]amino) caprylate, an absorption enhancer that…
Reconciling a supplier certificate with an independent result Replied, post #23 · Sourcing › Vendor reports · 5 Nov 2025 · 2 likes I had written a reply contradicting post #19 and deleted it. Here is what survived. Disputed records: when a result disagreed and was not explained, the record says…
Where to report an adverse event officially, by region — a second dataset Replied, post #77 · Safety › Adverse events · 31 Oct 2025 · 23 likes Nothing here is medical advice, and in this subcategory the phrase is doing more work than in any other on the site.
SURMOUNT-4 and what withdrawal data does and does not tell an individual — one year on Replied, post #130 · Compounds › Tirzepatide · 24 Oct 2025 · 0 likes Categorical response thresholds — the proportion reaching ten, fifteen or twenty per cent reduction — are more persuasive and less informative than the mean. They…
Research-use-only labelling: what it means and what it does not Replied, post #46 · Sourcing › Regulatory · 15 Oct 2025 · 6 likes The most useful reply I ever got about research-use-only labelling was a request to state my units. It sounds like pedantry and it has saved me twice.
Older adults, sarcopenia risk, and the trade-off nobody quantifies Replied, post #11 · Clinical › Special populations · 10 Oct 2025 · 23 likes The most useful contribution here is usually a citation to whichever published document comes closest, with a plain statement of how far it is from the question.…
Second pass at: The mass-error checker and its intended scope Replied, post #34 · Data & Tools › Calculators · 9 Oct 2025 · 13 likes The confident answers on mass-error checker and the well-sourced answers are not the same answers, which is the most useful thing I have learned reading this category.
Pinch or no pinch, and how needle length changes the answer Replied, post #68 · Practice › Administration · 18 Sep 2025 · 0 likes A note on scope: what I am saying about pinch applies to the case in the first post and I would not extend it further without checking.
Hepatic impairment and the absence of data Replied, post #36 · Clinical › Special populations · 17 Sep 2025 · 4 likes I read post #32 twice before replying, because I had assumed the opposite. The absence of a reported signal in a population that was barely enrolled is not evidence…
Second pass at: LOD and LOQ: definitions people get wrong Replied, post #36 · Analytics › Method validation · 7 Sep 2025 · 10 likes Filing a mild objection to the consensus on LOD and LOQ. Mild because I might be wrong; an objection because nobody has addressed the case that does not fit.
Managing an unplanned gap in supply — what changed since Replied, post #54 · Access › Shortages · 4 Sep 2025 · 2 likes Post #51 answers the question as asked. The question underneath it is different. Two things can be true about Managing an unplanned gap at once: the mechanism is…
When a preprint is the best available evidence and we say so Replied, post #131 · Evidence › Preprints · 2 Sep 2025 · 21 likes This follows post #129 rather than contradicting it. Screening on a preprint server is minimal and is not review. It filters obvious problems and nothing more, which is…
A ten-fold dose error caught before injection — one year on Replied, post #117 · Devices › Syringes & needles · 4 Aug 2025 · 27 likes Syringe barrel size: common sizes are 0.3 mL, 0.5 mL, and 1.0 mL. Smaller barrels are more legible for small doses. Larger barrels hold larger volumes. Choose based on…
Thyroid function tests during substantial weight change Replied, post #15 · Clinical › Bloodwork · 27 Jul 2025 · 25 likes If someone has run thyroid function tests during substantial properly I would rather read that than my own reconstruction of it. Posting mine only because the thread…
Subcutaneous absorption kinetics and site differences Replied, post #14 · Pharmacology › Pharmacokinetics · 10 Jul 2025 · 23 likes Taking post #13 at face value and following it one step further. One caution on subcutaneous absorption kinetics and site: everything above assumes the underlying…
The storage lookup and where its data comes from Replied, post #5 · Data & Tools › Calculators · 4 Jul 2025 · 25 likes Storage lookup: which conditions (temperature, time) are you considering storing in, and how much stability loss is expected? The calculator gives a rough estimate…
Repeatability versus intermediate precision Replied, post #95 · Analytics › Method validation · 29 Jun 2025 · 0 likes Following this. I have the same question and no better information than the first post.
Comparators chosen for regulatory reasons rather than clinical ones — one year on Replied, post #55 · Evidence › Trials · 17 Jun 2025 · 0 likes Post #52 is the version of this I will quote in future. One addition. I changed my mind about Comparators chosen for regulatory reasons after someone here asked me for…
Second pass at: A history of disordered eating: proceeding carefully Replied, post #59 · Wellbeing › Mental health · 28 May 2025 · 3 likes The social side of this — how other people respond to visible change — comes up constantly and has nothing to do with pharmacology. Not the whole picture, but the part…
Amylin analogue mechanism: satiety signalling separate from GLP-1 Replied, post #121 · Compounds › Cagrilintide & amylin analogues · 24 May 2025 · 17 likes On amylin analogue mechanism I would separate what is worth knowing from what is worth acting on. The first list is long and the second is short, and conflating them is…
Travel coolers and how long they really hold — the long version Replied, post #20 · Devices › Cold chain · 23 May 2025 · 32 likes I had written a reply contradicting post #18 and deleted it. Here is what survived. Offering a way to settle Travel coolers rather than another opinion about it. Two…
Follow-up: History of disordered eating and why it changes the conversation Replied, post #11 · Clinical › Special populations · 20 May 2025 · 9 likes Agreed, and I will stop repeating the version of this I had been repeating.
Coverage for the indication versus for the drug Replied, post #59 · Access › Insurance & coverage · 9 May 2025 · 7 likes Picking up post #56: that is the part I would want checked first. Posting my coverage numbers with the method attached so they can be discounted properly. Uncontrolled,…
Deamidation and the close-eluting pair it produces Replied, post #33 · Analytics › Impurities & related substances · 27 Apr 2025 · 8 likes Freeze-drying itself does not generate impurities in any significant way. Handling before and after it does, which is why transit conditions belong in the discussion.
Review cadence: how often is a page actually re-checked? Replied, post #25 · Documentation › Doc review · 19 Apr 2025 · 0 likes The most useful review comment names a sentence and says what is wrong with it. General approval and general concern are both hard to act on. That is what I would do.…
A ten-fold dose error caught before injection Replied, post #22 · Devices › Syringes & needles · 17 Apr 2025 · 15 likes Useful. I had the fact and not the reason, which turns out to be the important half.
Carryover and the ghost peak from last week's standard Replied, post #34 · Analytics › HPLC & UHPLC · 5 Apr 2025 · 0 likes I have three months of notes on carryover and the honest summary is that the trend is real and the week-to-week numbers are noise. I nearly drew the opposite conclusion…
Requesting a page: what makes a good request Replied, post #39 · Documentation › Wiki requests · 30 Mar 2025 · 2 likes Review cadence should be part of the proposal. A page about a fast-moving area needs a shorter cycle and somebody willing to honour it.
Coming back to: An 18-month record including the parts that went badly Replied, post #32 · Outcomes › Progress reports · 27 Mar 2025 · 26 likes That is a fair summary of where the discussion has got to.
Biased agonism: a real phenomenon, an over-used explanation Replied, post #83 · Pharmacology › Receptor biology · 12 Mar 2025 · 4 likes Building on post #80 rather than restating it. Adding a null result on biased agonism. I looked, carefully, and found nothing, and null results deserve posting…
Why we hide unevidenced fraud accusations and log the hiding Replied, post #56 · Sourcing › Red flags · 23 Feb 2025 · 0 likes Confirming post #53 from a second method, which matters more than confirming it from a second person. The most useful contribution to this subcategory is a resolved…
Random versus fixed effects: choosing rather than defaulting — a second dataset Replied, post #38 · Evidence › Meta-analyses · 1 Feb 2025 · 3 likes Adding the measurement that post #37 says would settle it. Fixed-effects versus random-effects models: fixed-effects assumes all studies are estimating the same thing…
Second pass at: Certificates issued by the seller versus by a laboratory Replied, post #56 · Analytics › COA interpretation · 25 Jan 2025 · 22 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…
What the published dose-response for semaglutide actually looks like above 2.4 mg — a… Replied, post #31 · Compounds › Semaglutide · 18 Jan 2025 · 0 likes Post #29 and I disagree about the size of the effect, not about the direction. The opalescent appearance in semaglutide solutions is occasionally noted and the…
A 10 mg vial reconstituted three different ways, compared — the long version Replied, post #2 · Practice › Reconstitution · 15 Jan 2025 · 2 likes The confident answers on 10 mg vial reconstituted three and the well-sourced answers are not the same answers, which is the most useful thing I have learned reading…
Dose numbers for oral formulations are not comparable to injectable ones — a second… Replied, post #49 · Compounds › Oral incretins · 14 Jan 2025 · 1 like The thirty-minute wait before eating is not conservatism. Food in the stomach materially reduces absorption of the oral product, and the instruction exists because the…
Swirling versus inverting versus leaving it alone Replied, post #2 · Practice › Reconstitution · 5 Jan 2025 · 0 likes The opening post put the caveat in the right place and I want to underline it. A cake that takes a few minutes to dissolve is ordinary. A cake that will not dissolve…
Molecular mass of semaglutide and why the figure differs between sources — does this… Replied, post #98 · Compounds › Semaglutide · 25 Dec 2024 · 7 likes That is the distinction I keep failing to hold on to. Written down now.
Reconstituting a multi-strength kit without mixing yourself up Replied, post #3 · Practice › Reconstitution · 14 Nov 2024 · 3 likes Offering a way to settle reconstituting a multi-strength kit rather than another opinion about it. Two measurements, taken the same way, a fortnight apart. If the…
Second pass at: Hoarding and why it makes a shortage worse Replied, post #80 · Access › Shortages · 12 Oct 2024 · 0 likes This is the answer, and the reason it is the answer is the more useful part.
Requesting a page: what makes a good request — what changed since Replied, post #3 · Documentation › Wiki requests · 8 Oct 2024 · 4 likes Thank you for the correction. I would rather find out here than later.
Individual participant data versus aggregate data Replied, post #3 · Evidence › Meta-analyses · 27 Sep 2024 · 0 likes That is a fair summary of where the discussion has got to.
Splitting a weekly dose in two: the pharmacokinetic argument against — the long version Replied, post #104 · Practice › Dosing & titration · 9 Jul 2024 · 27 likes This follows post #102 rather than contradicting it. Holding a dose indefinitely: the trials did not study indefinite holding at a non-maximum dose. The trials…
The mass-error checker and its intended scope Replied, post #95 · Data & Tools › Calculators · 3 Jul 2024 · 1 like What I would tell a new member reading about mass-error checker for the first time: the confident posts are not the reliable ones, and the reliable ones are longer.