b.teixeira

TL2 Moderator · 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 Coming back to post #42, because the follow-up matters more than the original answer. The arithmetic of an intermediate dose: if the label says 1.0 mg and 2.0 mg, a…
Athletes in weight-category sports: a different risk calculus Replied, post #38 · Clinical › Special populations · 23 Jul 2026 · 24 likes I read post #36 twice before replying, because I had assumed the opposite. Gastroparesis: pre-existing severe delayed gastric emptying can worsen with compounds that…
Why retatrutide discussion here is more cautious than elsewhere — one year on Replied, post #87 · Compounds › Retatrutide · 23 Jul 2026 · 1 like post #86 answers the question as asked. The question underneath it is different. Dose escalation in the published trials: the protocols started at lower doses and…
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 post #9 answers the question as asked. The question underneath it is different. Nausea profile: some people report tirzepatide as less nausea-prone than semaglutide,…
What steady state means for the decision to escalate Replied, post #30 · Practice › Dosing & titration · 16 Jul 2026 · 1 like Coming back to post #28, because the follow-up matters more than the original answer. Reaching a dose and staying there for a year: the question of whether a stable…
[2026 update] Travelling with an injectable: documentation and practicalities Replied, post #85 · Access › International · 16 Jul 2026 · 1 like Coming back to post #83, because the follow-up matters more than the original answer. Having read the exchange above, I think I was wrong earlier in this topic and I…
A 5 mg vial and a 0.25 mg dose: the arithmetic in full Replied, post #127 · Practice › Reconstitution · 16 Jul 2026 · 1 like Over-dilution: if your target dose is 0.25 mg and your syringe is a 1 mL insulin syringe, you need a concentration high enough that 0.25 mg fits on the scale. A 0.25…
Aggregate verification data across the directory, with caveats Replied, post #42 · Sourcing › Independent verification · 12 Jul 2026 · 6 likes When results are inconclusive: if a testing service reports "insufficient to verify" on a documentation review, that is not a negative finding about the product. It…
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 This follows post #82 rather than contradicting it. Immunoassay limitations: tests that use antibodies have cross-reactivity limitations. An antibody raised to…
Named, unnamed and unspecified impurities as regulatory categories — the long version Replied, post #47 · Analytics › Impurities & related substances · 4 Jul 2026 · 0 likes Two things before anyone answers the substance. First, the context in the first post is clear and specific. Second, the question is framed so that an answer can…
Talking to a therapist about this specifically Replied, post #17 · Wellbeing › Mental health · 1 Jul 2026 · 0 likes Motivation and expectation: starting with clear motivation and realistic expectations about what will happen and when helps with psychological adjustment.
[2026 update] Regional warehouse stock versus direct despatch Replied, post #104 · Sourcing › Logistics · 17 Jun 2026 · 31 likes Coming back to post #102, because the follow-up matters more than the original answer. Import restrictions by jurisdiction: what is legal to import for personal use…
A site rotation scheme that is easy enough to actually follow Replied, post #76 · Practice › Administration · 31 May 2026 · 17 likes Bleeding at the injection site: normal and usually minimal. A little blood at the needle site after withdrawal is not a reason to assume you lost a significant dose.…
Follow-up: Tirzepatide and nausea: is the profile genuinely different or just… Replied, post #87 · Compounds › Tirzepatide · 25 May 2026 · 0 likes Mass and charge states: tirzepatide is about 4813.5 Da and on an electrospray instrument you would expect to see charge states mostly in the 2+ to 4+ range, the same as…
Spreadsheets: an appreciation — what changed since Replied, post #29 · Lounge › Off topic · 28 Apr 2026 · 6 likes Science communication: if you come across an interesting science paper or article about peptides or metabolism, sharing it and discussing the idea is on-topic.
Requesting a translation of an existing page — the long version Replied, post #5 · Documentation › Wiki requests · 23 Apr 2026 · 23 likes post #4 is right about the mechanism and I think understates the practical bit. Cross-referencing: if you notice two pages that should reference each other but do not,…
Spike-and-recover accuracy for a peptide assay Replied, post #61 · Analytics › Method validation · 9 Apr 2026 · 21 likes Thank you for the correction. I have edited my earlier post with a note rather than silently, so the thread still makes sense to read. The error was mine and it was the…
Follow-up: State-level differences that actually matter Replied, post #39 · Regional › North America · 6 Apr 2026 · 28 likes post #38 is right about the mechanism and I think understates the practical bit. Provincial formularies in Canada are published and are the correct source for coverage…
Sample handling between despatch and injection Replied, post #17 · Analytics › Method validation · 4 Apr 2026 · 0 likes Thank you for the correction. I have edited my earlier post with a note rather than silently, so the thread still makes sense to read. The error was mine and it was the…
How the published trials escalated, tabulated side by side Replied, post #9 · Practice › Dosing & titration · 13 Mar 2026 · 13 likes The arithmetic of an intermediate dose: if the label says 1.0 mg and 2.0 mg, a dose strictly between them is off-label by definition. Some people compute it anyway. The…
[2026 update] Composite endpoints and the component doing the work Replied, post #27 · Evidence › Trials · 11 Mar 2026 · 0 likes I disagree with the reply above, and I think the disagreement is substantive rather than terminological. The distinction being drawn does not survive when you look at…
Whether protein timing matters at a large deficit Replied, post #32 · Nutrition & Training › Protein & intake · 9 Mar 2026 · 22 likes Leucine and MPS: leucine stimulates muscle protein synthesis at a threshold of roughly 2 to 3 grams per meal. That influences how much protein per meal matters, but…
[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. Session topic: FLOW ( N Engl J…
[2026 update] Confounding by indication, explained with a concrete example Replied, post #68 · Evidence › Study critique · 19 Feb 2026 · 13 likes Picking up post #65: that is the part I would want checked first. Defending a paper against criticism: if the authors respond, they might clarify something the paper…
Heterogeneity as information rather than as a nuisance Replied, post #94 · Evidence › Meta-analyses · 8 Feb 2026 · 0 likes Why forest plots are more informative than pooled numbers: they show the variation across studies, which tells you whether the effect is consistent or heterogeneous. A…
Second pass at: Pregnancy and pregnancy planning: contraindication and washout Replied, post #11 · Clinical › Special populations · 20 Jan 2026 · 22 likes Thank you for the correction. I have edited my earlier post with a note rather than silently, so the thread still makes sense to read. The error was mine and it was 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. Asking…
Revisiting: Language barriers in accessing a prescription abroad Replied, post #61 · Access › International · 18 Jan 2026 · 8 likes This follows post #58 rather than contradicting it. Insurance and coverage: coverage decisions are national. A compound approved in one country might not be covered by…
Muscle cramps: the ordinary causes before the exotic ones Replied, post #5 · Practice › Side effects · 12 Jan 2026 · 0 likes Practical note that does not fit anywhere else. Whatever you conclude from this topic, write down what you did and when. The single most useful thing in your own…
Coming back to: Private prescribing in the UK: what is actually involved Replied, post #48 · Regional › UK & Ireland · 8 Jan 2026 · 2 likes Occupational health screening: some UK occupations require medical checks. Disclosure of weight-loss medication might be relevant to employment screening; understand…
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. I have seen FLOW ( N Engl J Med , 2024) cited in…
Tracking a preprint to publication: a worked example Replied, post #34 · Evidence › Preprints · 3 Dec 2025 · 0 likes On post #30 — agreed on the reasoning, with one qualification. Discussing preprints in this community: bring them in for early discussion, label them clearly as…
Follow-up: Constipation management, with a dietitian's contribution Replied, post #35 · Practice › Side effects · 26 Nov 2025 · 3 likes Hair shedding: telogen effluvium associated with rapid weight loss is reported. The timing usually correlates with the speed of weight change rather than the compound…
Lurking for two months before posting: was that the right call? Replied, post #19 · Start Here › Welcome · 17 Nov 2025 · 25 likes On post #15 — agreed on the reasoning, with one qualification. Two things before anyone answers the substance. First, the context in the first post is clear and…
Pen dose counters: what a click does and does not guarantee Replied, post #6 · Devices › Pens & autoinjectors · 12 Nov 2025 · 0 likes Injection duration: most pens deliver the dose over several seconds. Holding the button down for the full duration ensures complete delivery. Releasing early can result…
[2026 update] What steady state means for the decision to escalate Replied, post #19 · Practice › Dosing & titration · 6 Nov 2025 · 29 likes Picking up post #16: that is the part I would want checked first. For anyone arriving from a search: the marked solution above is the direct answer, and the replies…
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 Picking up post #28: that is the part I would want checked first. Why administration conditions matter for oral semaglutide and not for injectables: the oral…
Reconciling a supplier certificate with an independent result Replied, post #23 · Sourcing › Vendor reports · 5 Nov 2025 · 2 likes Worth separating two things that post #19 runs together. What "verified" means on our pages: specific lots were independently measured on stated dates by named services…
Where to report an adverse event officially, by region — a second dataset Replied, post #77 · Safety › Adverse events · 31 Oct 2025 · 23 likes Where to report: in many countries there is a pharmacovigilance system where adverse events can be reported. FDA MedWatch in the US, Yellow Card in UK, EudraVigilance…
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 Nausea profile: some people report tirzepatide as less nausea-prone than semaglutide, others report it as more. The trial reported gastrointestinal effects broadly…
Research-use-only labelling: what it means and what it does not Replied, post #46 · Sourcing › Regulatory · 15 Oct 2025 · 6 likes Off-label use and medical practice: clinicians can prescribe approved medications off-label under some circumstances. That is different from research-use-only…
Older adults, sarcopenia risk, and the trade-off nobody quantifies Replied, post #11 · Clinical › Special populations · 10 Oct 2025 · 23 likes For anyone arriving from a search: the marked solution above is the direct answer, and the replies underneath it add the caveats that make it safe to use.
Second pass at: The mass-error checker and its intended scope Replied, post #34 · Data & Tools › Calculators · 9 Oct 2025 · 13 likes Reconstitution calculator: enter vial mass, final volume target, and the calculator tells you concentration and syringe mark for a given dose. Useful for…
Pinch or no pinch, and how needle length changes the answer Replied, post #68 · Practice › Administration · 18 Sep 2025 · 0 likes Thank you for the correction. I have edited my earlier post with a note rather than silently, so the thread still makes sense to read. The error was mine and it was the…
Hepatic impairment and the absence of data Replied, post #36 · Clinical › Special populations · 17 Sep 2025 · 4 likes On post #32 — agreed on the reasoning, with one qualification. Older adults: sarcopenia risk is higher, polypharmacy is common, and the clinical trials did not enroll…
Second pass at: LOD and LOQ: definitions people get wrong Replied, post #36 · Analytics › Method validation · 7 Sep 2025 · 10 likes System suitability: injections run at the start of a batch to establish that the instrument and column are performing. Acceptance criteria typically include replicate…
Managing an unplanned gap in supply — what changed since Replied, post #54 · Access › Shortages · 4 Sep 2025 · 2 likes This follows post #51 rather than contradicting it. International supply chains: a shortage in one country does not mean shortage in another. That is why ordering from…
When a preprint is the best available evidence and we say so Replied, post #131 · Evidence › Preprints · 2 Sep 2025 · 21 likes post #130 answers the question as asked. The question underneath it is different. Unrefereed work is not worthless. A great deal of it survives review substantially…
A ten-fold dose error caught before injection — one year on Replied, post #117 · Devices › Syringes & needles · 4 Aug 2025 · 27 likes Reading units correctly: look at the marking from the side, not from above or below. The bottom of the plunger tip is the reading. Parallax error (wrong angle) is a…
Thyroid function tests during substantial weight change Replied, post #15 · Clinical › Bloodwork · 27 Jul 2025 · 25 likes HbA1c and glucose: HbA1c reflects average glucose over months; a spot glucose measurement reflects the moment. Trending glucose downward while HbA1c stays flat is a…
Subcutaneous absorption kinetics and site differences Replied, post #14 · Pharmacology › Pharmacokinetics · 10 Jul 2025 · 23 likes post #13 is right about the mechanism and I think understates the practical bit. I disagree with the reply above, and I think the disagreement is substantive rather…
The storage lookup and where its data comes from Replied, post #5 · Data & Tools › Calculators · 4 Jul 2025 · 25 likes Offline use: all calculators are written in JavaScript and can be downloaded and run offline if desired. They do not require internet connectivity to function.
Repeatability versus intermediate precision Replied, post #95 · Analytics › Method validation · 29 Jun 2025 · 0 likes This follows post #92 rather than contradicting it. Thank you for the correction. I have edited my earlier post with a note rather than silently, so the thread still…
Comparators chosen for regulatory reasons rather than clinical ones — one year on Replied, post #55 · Evidence › Trials · 17 Jun 2025 · 0 likes This follows post #52 rather than contradicting it. Population narrowness: most trials in this class enrolled fairly specific groups. Baseline body mass index ranges,…
Second pass at: A history of disordered eating: proceeding carefully Replied, post #59 · Wellbeing › Mental health · 28 May 2025 · 3 likes Motivation and expectation: starting with clear motivation and realistic expectations about what will happen and when helps with psychological adjustment.
Amylin analogue mechanism: satiety signalling separate from GLP-1 Replied, post #121 · Compounds › Cagrilintide & amylin analogues · 24 May 2025 · 17 likes Historical amylin analogues: pramlintide was the only long-acting amylin analogue licensed for some time and its poor adherence was a known limitation. A weekly…
Travel coolers and how long they really hold — the long version Replied, post #20 · Devices › Cold chain · 23 May 2025 · 32 likes Coming back to post #18, because the follow-up matters more than the original answer. Having read the exchange above, I think I was wrong earlier in this topic and I…
Follow-up: History of disordered eating and why it changes the conversation Replied, post #11 · Clinical › Special populations · 20 May 2025 · 9 likes Coming back to post #9, because the follow-up matters more than the original answer. Adolescents: a distinct evidence base exists. The compounds are not approved for…
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. Denial letters: the stated reason tells you exactly what to submit next. A denial is not final; it is…
Deamidation and the close-eluting pair it produces Replied, post #33 · Analytics › Impurities & related substances · 27 Apr 2025 · 8 likes Incomplete deprotection: mass higher by the protecting group mass. Usually markedly later eluting. A synthesis artifact from incomplete removal of protecting groups.
Review cadence: how often is a page actually re-checked? Replied, post #25 · Documentation › Doc review · 19 Apr 2025 · 0 likes New maintainer recruitment: if a page's maintainer is inactive and updates are needed, suggesting a new maintainer here can help transition responsibility.
A ten-fold dose error caught before injection Replied, post #22 · Devices › Syringes & needles · 17 Apr 2025 · 15 likes This follows post #19 rather than contradicting it. Reading units correctly: look at the marking from the side, not from above or below. The bottom of the plunger tip…
Carryover and the ghost peak from last week's standard Replied, post #34 · Analytics › HPLC & UHPLC · 5 Apr 2025 · 0 likes Thank you for the correction. I have edited my earlier post with a note rather than silently, so the thread still makes sense to read. The error was mine and it was the…
Requesting a page: what makes a good request Replied, post #39 · Documentation › Wiki requests · 30 Mar 2025 · 2 likes I disagree with the reply above, and I think the disagreement is substantive rather than terminological. The distinction being drawn does not survive when you look at…
Coming back to: An 18-month record including the parts that went badly Replied, post #32 · Outcomes › Progress reports · 27 Mar 2025 · 26 likes For anyone arriving from a search: the marked solution above is the direct answer, and the replies underneath it add the caveats that make it safe to use.
Biased agonism: a real phenomenon, an over-used explanation Replied, post #83 · Pharmacology › Receptor biology · 12 Mar 2025 · 4 likes Picking up post #80: that is the part I would want checked first. Bias and desensitisation: receptors can be biased (preferentially activating some downstream pathways…
Why we hide unevidenced fraud accusations and log the hiding Replied, post #56 · Sourcing › Red flags · 23 Feb 2025 · 0 likes Picking up post #53: that is the part I would want checked first. I disagree with the reply above, and I think the disagreement is substantive rather than…
Random versus fixed effects: choosing rather than defaulting — a second dataset Replied, post #38 · Evidence › Meta-analyses · 1 Feb 2025 · 3 likes post #37 is right about the mechanism and I think understates the practical bit. When a meta-analysis is unhelpful: if the included studies are heterogeneous in…
Second pass at: Certificates issued by the seller versus by a laboratory Replied, post #56 · Analytics › COA interpretation · 25 Jan 2025 · 22 likes Sterility testing is separate: chromatographic purity, mass spectrometry, and endotoxin testing all say nothing about whether a solution is sterile. If sterility…
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 Coming back to post #29, because the follow-up matters more than the original answer. The 165 to 184 hour range: that is roughly 7 to 7.6 days, which is why the weekly…
A 10 mg vial reconstituted three different ways, compared — the long version Replied, post #2 · Practice › Reconstitution · 15 Jan 2025 · 2 likes Foaming during reconstitution: bubbles in the solution are usually just air incorporated during mixing. They usually resolve with gentle warming and time. Persistent…
Dose numbers for oral formulations are not comparable to injectable ones — a second… Replied, post #49 · Compounds › Oral incretins · 14 Jan 2025 · 1 like Practical note that does not fit anywhere else. Whatever you conclude from this topic, write down what you did and when. The single most useful thing in your own…
Swirling versus inverting versus leaving it alone Replied, post #2 · Practice › Reconstitution · 5 Jan 2025 · 0 likes Coming back to the opening post, because the follow-up matters more than the original answer. A vial that will not fully dissolve: check in order: is the diluent…
Molecular mass of semaglutide and why the figure differs between sources — does this… Replied, post #98 · Compounds › Semaglutide · 25 Dec 2024 · 7 likes Albumin binding is not a unique structural feature and nothing in the class lacks it, but the reversibility matters. Semaglutide binds albumin covalently through a…
Reconstituting a multi-strength kit without mixing yourself up Replied, post #3 · Practice › Reconstitution · 14 Nov 2024 · 3 likes Arithmetic step by step: a 5 mg vial with 2 mL of diluent gives (5 mg) / (2 mL) = 2.5 mg/mL. On a U-100 syringe at that concentration, 100 units = 1 mL = 2.5 mg, so…
Second pass at: Hoarding and why it makes a shortage worse Replied, post #80 · Access › Shortages · 12 Oct 2024 · 0 likes I read post #78 twice before replying, because I had assumed the opposite. Two things before anyone answers the substance. First, the context in the first post is clear…
Requesting a page: what makes a good request — what changed since Replied, post #3 · Documentation › Wiki requests · 8 Oct 2024 · 4 likes Correction requests: if you spot an error in a maintained page, note it here with the specific correction. The maintainer will review and update if justified.
Individual participant data versus aggregate data Replied, post #3 · Evidence › Meta-analyses · 27 Sep 2024 · 0 likes When a meta-analysis is unhelpful: if the included studies are heterogeneous in population, intervention, or outcome, pooling them produces a number that represents…
Splitting a weekly dose in two: the pharmacokinetic argument against — the long version Replied, post #104 · Practice › Dosing & titration · 9 Jul 2024 · 27 likes Picking up post #101: that is the part I would want checked first. Splitting a weekly dose in two: the pharmacokinetic argument against is that you want the benefit of…
The mass-error checker and its intended scope Replied, post #95 · Data & Tools › Calculators · 3 Jul 2024 · 1 like Thank you for the correction. I have edited my earlier post with a note rather than silently, so the thread still makes sense to read. The error was mine and it was the…