IHollingworth

TL2 Member · Zürich, CH

Here for the documentation. Occasionally files a wiki request when a page has drifted out of date.

Joined 2 October 2024 · last posted 21d

96 posts, newest first. Showing up to 150.

Insurance and replacement policies, compared Replied, post #70 · Sourcing › Logistics · 7 Jul 2026 · 0 likes I would keep insurance and replacement policies and the decision it usually gets used for separate in this thread. They are related and they are not the same question,…
Prescription requirements and telehealth models — a second dataset Replied, post #89 · Sourcing › Regulatory · 3 Jul 2026 · 0 likes Generic or biosimilar entry depends on patent and exclusivity positions that are jurisdiction-specific and are frequently misreported. That is the honest state of it as…
Why cagrilintide alone is discussed so much less than in combination — does this still… Replied, post #17 · Compounds › Cagrilintide & amylin analogues · 1 Jul 2026 · 16 likes The honest summary of the evidence base: a coherent mechanism, good phase 2 data in combination, and much less standalone human data than the volume of discussion…
[2026 update] Does a peptide degrade silently, with no visual change? Replied, post #81 · Practice › Storage & stability · 30 Jun 2026 · 12 likes Narrowing post #80, because the general version has more than one answer. Where I would push back on the peptide consensus is the confidence, not the direction. The…
Revisiting: How this community labels and discusses unrefereed work Replied, post #5 · Evidence › Preprints · 20 Jun 2026 · 0 likes Where I part company with the opening post, and it is a narrow parting. Worth separating community labels as a question about the compound from community labels as a…
Official shortage notices and what they authorise Replied, post #118 · Access › Shortages · 20 Jun 2026 · 0 likes Where I part company with post #114, and it is a narrow parting. Dose hold versus tapering: if a temporary shortage forces a gap, holding your dose and resuming when…
Naming conventions for research peptides and the confusion they cause Replied, post #15 · Compounds › Other compounds · 13 Jun 2026 · 18 likes The question underneath naming conventions for research peptides is usually "how would I tell?" rather than "what is true?", and that one has a method attached to it.…
Second pass at: Metformin co-administration and additive GI effects Replied, post #123 · Practice › Interactions · 10 Jun 2026 · 7 likes Answering the question post #121 raises rather than the one it answers. Anticoagulant questions come up regularly and are the clearest case for professional advice…
Books and papers worth reading that are not about this at all — one year on Replied, post #7 · Lounge › Off topic · 10 Jun 2026 · 0 likes Lounge-appropriate observation. I have started reading the certificates that come with things I buy that have nothing to do with any of this, and the standard elsewhere…
Coming back to: Specificity, linearity, accuracy, precision, range, robustness — with… Replied, post #48 · Analytics › Method validation · 9 Jun 2026 · 0 likes Linearity across the working range is a routine demonstration and it constrains how far a result can be extrapolated. A method linear from 80 to 120 per cent of nominal…
A certificate whose chromatogram axes do not match its stated method — one year on Replied, post #48 · Sourcing › Red flags · 4 Jun 2026 · 23 likes Evasion when asked: if a supplier does not clarify when asked specifically for method details, counter-ion form, or batch origin, that itself is a red flag worth…
Semaglutide and gastric emptying — the mechanism behind most of the side-effect profile Replied, post #45 · Compounds › Semaglutide · 30 May 2026 · 1 like Small correction to my own earlier position on semaglutide and gastric emptying. I had the units the wrong way round, which changes the conclusion by an order of…
Coming back to: Solubility limits and what a cloudy solution is telling you Replied, post #27 · Pharmacology › Formulation chemistry · 30 May 2026 · 7 likes Nothing to add on the substance. Thank you for taking the question at face value.
Constipation management, with a dietitian's contribution Replied, post #70 · Practice › Side effects · 26 May 2026 · 11 likes Good question, well framed, and I would like to see it answered properly.
Tracking intake honestly when appetite is absent Replied, post #33 · Nutrition & Training › Protein & intake · 22 May 2026 · 21 likes Coming back to post #29, because the follow-up matters more than the original answer. My experience of tracking intake contradicts the reply above. I am posting it as a…
Step therapy requirements and how to satisfy them Replied, post #20 · Access › Insurance & coverage · 18 May 2026 · 12 likes The reason step therapy requirements keeps being re-asked is that the answer is conditional and people quote it without the condition. It is not that the answer is…
An 18-month record including the parts that went badly Replied, post #14 · Outcomes › Progress reports · 11 May 2026 · 31 likes Self-reported intake is optimistic in a consistent direction, and saying so in your own report is more credible than not.
Coming back to: Lateral-flow and colorimetric approaches: the specificity problem Replied, post #15 · Analytics › Home & field testing · 5 May 2026 · 0 likes Post #12 describes the usual case. This is about the unusual one. What physical quantity does the device measure? A colorimetric or lateral-flow method typically…
Blind submission and why it changes minds — the long version Replied, post #51 · Sourcing › Independent verification · 1 May 2026 · 0 likes Understood. Thank you for being specific about the limits of it.
Shakes versus food: a pragmatic assessment Replied, post #6 · Nutrition & Training › Protein & intake · 26 Apr 2026 · 21 likes Post #5 answers the question as asked. The question underneath it is different. Where I have landed on shakes versus food, having got it wrong once in public: the…
[2026 update] What a purity-only report leaves out Replied, post #95 · Sourcing › Independent verification · 18 Apr 2026 · 21 likes Post #92 is right about the mechanism and I think understates the practical bit. Repeat determination on the same product line months apart is the measurement that…
Bug report: the reconstitution calculator and a rounding edge case Replied, post #31 · Data & Tools › Calculators · 5 Apr 2026 · 17 likes Reconstitution calculator: enter vial mass, final volume target, and the calculator tells you concentration and syringe mark for a given dose. Useful for…
Grapefruit: why this class is not the class that cares Replied, post #121 · Practice › Interactions · 5 Apr 2026 · 0 likes Post #118 is the version of this I will quote in future. One addition. A supplement is a drug for interaction purposes, and the fact that it is sold without a…
Why the titration planner refuses to produce a schedule below a floor Replied, post #53 · Data & Tools › Calculators · 24 Mar 2026 · 0 likes Dose equivalence calculator: compounds have different potencies. The calculator is provided with a caveat: "equivalence" is not precise and individual response varies.…
What "marked as solution" means and who gets to mark it — does this still hold? Replied, post #57 · Start Here › Welcome · 24 Mar 2026 · 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…
Journal club: is percentage weight change the right endpoint? Started this topic · Evidence › Journal club · 17 Mar 2026 · 14 likes Journal club: is percentage weight change the right endpoint? I have a specific reason for asking rather than idle curiosity, and the context is below. Bringing a claim…
Follow-up: Evidence quality in the secretagogue literature: an honest assessment Replied, post #19 · Compounds › Secretagogues & GH axis · 13 Mar 2026 · 26 likes I would put moderate confidence on the mainstream reading of Evidence quality and no more. That is not scepticism for its own sake; it is where the sourcing actually…
Measurement error in home scales, with a worked standard deviation — the long version Replied, post #46 · Research Methods › Statistics · 5 Mar 2026 · 13 likes Whatever the answer on Measurement error in home scales turns out to be, the method for getting there is the same: state the assumption, do the arithmetic in public,…
Interpreting a result that disagrees with the supplier's certificate Replied, post #147 · Sourcing › Independent verification · 3 Mar 2026 · 1 like Combining a chromatographic result with a documentation review gives a more complete picture than two chromatographic results, because the failure modes are different.
[2026 update] Confounding by indication, explained with a concrete example Replied, post #97 · Evidence › Study critique · 1 Mar 2026 · 15 likes This follows post #94 rather than contradicting it. Hold a trial to the standard something could actually have met. A criticism that no achievable design could have…
Research-use-only labelling: what it means and what it does not Replied, post #101 · Sourcing › Regulatory · 11 Feb 2026 · 4 likes The reason research-use-only labelling is hard to answer is that the obvious measurement and the relevant quantity are not the same thing, and substituting one for the…
Dead volume across syringe and needle combinations Replied, post #63 · Devices › Syringes & needles · 30 Jan 2026 · 19 likes Dead volume across syringe has been discussed here with more heat than it deserves, mostly because two definitions have been in play the whole time.
Pinch or no pinch, and how needle length changes the answer — the long version Replied, post #10 · Practice › Administration · 18 Jan 2026 · 16 likes Pinch is worth one more sentence than it usually gets, and the sentence is the one about how the number was arrived at.
[2026 update] Publication patterns in the BPC-157 literature, examined Replied, post #5 · Compounds › Repair & healing peptides · 15 Jan 2026 · 0 likes Publication patterns in the BPC-157 literature: a large proportion of the evidence comes from one research group. That is not necessarily wrong — one group can do…
What to include when your question involves a chromatogram Replied, post #14 · Start Here › How to Ask · 1 Jan 2026 · 25 likes A photograph of a vial is rarely useful and a photograph of a document usually is. Redact the identifiers before you post either.
How to read a phase 2 result without treating it as a phase 3 result Replied, post #35 · Compounds › Retatrutide · 27 Dec 2025 · 10 likes The phase 2 obesity paper reported dose-dependent weight reduction of a magnitude that attracted attention. It also reported dose-dependent heart-rate increases. The…
Revisiting: A page that has drifted out of date and needs a maintainer Replied, post #6 · Documentation › Wiki requests · 20 Dec 2025 · 0 likes Confirming post #5 from a second method, which matters more than confirming it from a second person. The most useful requests here identify a specific confusion that…
Journal club: PIONEER 6 as a safety trial Replied, post #11 · Evidence › Journal club · 15 Dec 2025 · 0 likes Reading order that works for these sessions: registry entry, methods, baseline table, primary result, then abstract last. Reading the abstract first anchors everything…
Dizziness on standing and the electrolyte explanation — does this still hold? Replied, post #22 · Practice › Side effects · 5 Dec 2025 · 11 likes I have three months of notes on Dizziness on standing and the honest summary is that the trend is real and the week-to-week numbers are noise. I nearly drew the…
AOD-9604 and the fragment hypothesis, revisited Replied, post #32 · Compounds › Other compounds · 3 Dec 2025 · 6 likes Post #31 is right about the mechanism and I think understates the practical bit. AOD-9604 has been discussed here with more heat than it deserves, mostly because two…
Oral versus injectable exposure: comparing apples to a different fruit Replied, post #13 · Compounds › Oral incretins · 15 Nov 2025 · 30 likes Post #12 answers the question as asked. The question underneath it is different. Dose numbers for oral formulations are not comparable to injectable ones. The 14 mg…
Reading an interaction checker output critically Replied, post #42 · Practice › Interactions · 13 Nov 2025 · 14 likes Anticoagulant questions come up regularly and are the clearest case for professional advice rather than discussion, because the consequence of being wrong is not…
Getting a referral rather than a refusal Replied, post #3 · Clinical › Prescriber conversations · 10 Nov 2025 · 3 likes The opening post describes the usual case. This is about the unusual one. Bringing a record of symptoms with dates and severities makes an assessment materially easier…
Revisiting: GLP-1 receptor distribution: central and peripheral Replied, post #59 · Pharmacology › Receptor biology · 30 Oct 2025 · 24 likes Useful. I had the fact and not the reason, which turns out to be the important half.
New subcategory: rationale and scope Replied, post #117 · Meta › Announcements · 25 Oct 2025 · 1 like Picking up post #114: that is the part I would want checked first. Worth saying publicly: stepping back cleanly and handing over is a service. Documents with an absent…
Payment mechanics and the recovery options that do not exist Replied, post #56 · Sourcing › Payments · 21 Oct 2025 · 22 likes Answering the payment mechanics question as asked, then the question I think is meant. As asked: yes, with the qualification below. As meant: it depends on how the…
SURMOUNT-4 and what withdrawal data does and does not tell an individual — one year on Replied, post #48 · Compounds › Tirzepatide · 21 Oct 2025 · 29 likes Answering the question post #46 raises rather than the one it answers. I keep a log for SURMOUNT-4 specifically because my memory of it turned out to be systematically…
Pinch or no pinch, and how needle length changes the answer Replied, post #114 · Practice › Administration · 16 Oct 2025 · 2 likes If you have to inject at a different time of day than usual, that is a much smaller perturbation than it feels for a weekly compound with a week-long half-life.
Pinch or no pinch, and how needle length changes the answer Replied, post #100 · Practice › Administration · 8 Oct 2025 · 5 likes Bleeding at the site is common and unremarkable at these needle gauges. Persistent bruising in the same area repeatedly is worth a change of technique or of site rather…
Coming back to: What published stability data actually covers, and what it does not Replied, post #139 · Practice › Storage & stability · 13 Sep 2025 · 5 likes Where I part company with post #137, and it is a narrow parting. What I would want before treating published stability data actually covers as settled: the method, the…
How the vendor documentation pages are maintained, and by whom — what changed since Replied, post #55 · Sourcing › Vendor reports · 12 Sep 2025 · 15 likes Reports of ordinary results are more valuable than reports of remarkable ones, precisely because only the remarkable ones get posted elsewhere.
When to stop reading forums, including this one Replied, post #24 · Wellbeing › Mental health · 11 Sep 2025 · 0 likes This follows post #21 rather than contradicting it. Support and community: some people process weight change through community (online or in-person). Others prefer…
Coming back to: Sample size calculations, read backwards from the published number Replied, post #87 · Evidence › Trials · 6 Sep 2025 · 0 likes That is clearer than the version I had in my head. Thank you.
Temperature loggers worth the money Replied, post #23 · Devices › Cold chain · 27 Aug 2025 · 1 like Assessing an excursion: if a package sat at room temperature for a time, visual inspection (cloudiness, discoloration, particles) can alert you to problems. Not visible…
An emergency department visit, described afterwards Replied, post #58 · Safety › Adverse events · 25 Aug 2025 · 13 likes Worth separating two things that post #56 runs together. Injection-site reactions that spread over a day or come with systemic symptoms are a different observation from…
[2026 update] What we do not know about retatrutide, listed explicitly Replied, post #48 · Compounds › Retatrutide · 14 Aug 2025 · 6 likes Marking my place. If it changes for me I will come back and say so.
[2026 update] Journal club: is percentage weight change the right endpoint? Replied, post #8 · Evidence › Journal club · 9 Aug 2025 · 16 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.
How to research a compound with no human data without deceiving yourself Replied, post #77 · Compounds › Other compounds · 3 Aug 2025 · 2 likes I read post #73 twice before replying, because I had assumed the opposite. Thymosin alpha-1 has a regulatory history in several jurisdictions and a real clinical…
Follow-up: The decimal-point error, and the habit that catches it Replied, post #29 · Practice › Reconstitution · 22 Jul 2025 · 29 likes Write the reconstitution date and the concentration on the vial. Not on a note, on the vial. Every account here of a dosing error involving the wrong concentration…
A field-by-field walk through a certificate of analysis Replied, post #67 · Analytics › COA interpretation · 16 Jul 2025 · 2 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…
Coming back to: Nausea profile of amylin analogues compared with GLP-1 agonists Replied, post #49 · Compounds › Cagrilintide & amylin analogues · 11 Jul 2025 · 2 likes Whatever the answer on Nausea profile of amylin analogues turns out to be, the method for getting there is the same: state the assumption, do the arithmetic in public,…
Journal club: SURMOUNT-1, read without the press release Replied, post #155 · Evidence › Journal club · 10 Jul 2025 · 0 likes SELECT (N Engl J Med 2023): Semaglutide cardiovascular outcomes without diabetes. The first outcome trial in people without diabetes, which decoupled the cardiovascular…
Whether an aggregate is worth publishing at all: a disputed topic Replied, post #24 · Data & Tools › Datasets · 4 Jul 2025 · 4 likes Self-reported, unblinded, self-selected data has known biases and is still worth collecting, provided every one of those words appears in the description. I am…
Comparing my trajectory with the trial curves, carefully Replied, post #18 · Outcomes › Progress reports · 27 Jun 2025 · 5 likes If a pattern survives a rolling-mean treatment it is worth explaining. Most do not, and that is the useful finding. The general case is well covered; this is the…
BPC-157: what the rodent literature actually shows, and what it does not Replied, post #4 · Compounds › Repair & healing peptides · 26 May 2025 · 0 likes Useful. I had the fact and not the reason, which turns out to be the important half.
Coming back to: Semaglutide half-life: where the 165 to 184 hour figure comes from Started this topic · Compounds › Semaglutide · 18 May 2025 · 39 likes Semaglutide half-life: where the 165 to 184 hour figure comes from Writing it up because I had to work it out twice and would rather nobody else did. Putting the…
Antibiotics and a course of something with delayed emptying Replied, post #40 · Practice › Interactions · 13 May 2025 · 11 likes Thyroid medications: semaglutide is associated with a slowing of gastric emptying, which might affect thyroid medication absorption if they are taken very close…
Adjudicated events and why the definition matters — the long version Replied, post #113 · Evidence › Trials · 22 Apr 2025 · 31 likes Post #109 put the caveat in the right place and I want to underline it. Checked the Adjudicated events claim against the primary source this morning. It survives, with…
Requesting a page: what makes a good request Replied, post #58 · Documentation › Wiki requests · 15 Apr 2025 · 3 likes No notes. Posting so the count is not one.
A certificate with no method stated: what can you conclude? Replied, post #46 · Analytics › COA interpretation · 8 Apr 2025 · 3 likes The arithmetic in post #43 is right; the assumption feeding it is the part to check. Reading old certificates: if a certificate is dated years ago, the lot it describes…
Domestic fridge temperature mapping: a cheap experiment — what changed since Replied, post #80 · Devices › Cold chain · 6 Apr 2025 · 2 likes Post #76 and I disagree about the size of the effect, not about the direction. A temperature indicator that has tripped tells you a threshold was crossed. It does not…
Why cagrilintide alone is discussed so much less than in combination Replied, post #76 · Compounds › Cagrilintide & amylin analogues · 31 Mar 2025 · 9 likes On post #74 — agreed on the reasoning, with one qualification. Research-use-only cagrilintide is not approved for human use and the published evidence base is a…
Preservatives: function, testing, and limits Replied, post #25 · Pharmacology › Formulation chemistry · 28 Mar 2025 · 17 likes Worth separating two things that post #23 runs together. Counter-ion exchange from trifluoroacetate to acetate is a purification step with a cost, and material sold…
Assessing a warm arrival: the decision process Replied, post #16 · Sourcing › Logistics · 20 Mar 2025 · 11 likes Building on post #15 rather than restating it. Worth separating assessing a warm arrival as a question about the compound from assessing a warm arrival as a question…
Counter-ion form: the field almost nobody reports — one year on Replied, post #88 · Analytics › COA interpretation · 16 Mar 2025 · 0 likes Purity and content are different measurements: purity tells you what proportion of the detected material is the intended species. Content tells you how much of the…
Charge states for a 4 kDa peptide, worked through Replied, post #109 · Analytics › Mass spectrometry · 15 Mar 2025 · 0 likes Filing a mild objection to the consensus on charge states. Mild because I might be wrong; an objection because nobody has addressed the case that does not fit.
Biased agonism: a real phenomenon, an over-used explanation Replied, post #69 · Pharmacology › Receptor biology · 9 Mar 2025 · 0 likes Post #66 is right about the mechanism and I think understates the practical bit. What I can speak to on biased agonism is narrow, so I will keep it narrow rather than…
Pharmaceutical compounding rules, summarised from primary sources Replied, post #140 · Sourcing › Regulatory · 5 Mar 2025 · 10 likes A compound in a compounding pathway in one country and unavailable in another is a common situation and produces most of the confusion here.
Canadian access and provincial variation Replied, post #42 · Regional › North America · 1 Feb 2025 · 0 likes Coming back to post #38, because the follow-up matters more than the original answer. Practical experience of canadian access and provincial variation, offered as one…
Levothyroxine timing: a real interaction with a simple fix Replied, post #22 · Practice › Interactions · 16 Jan 2025 · 7 likes Oral medications with a narrow therapeutic index are the ones where that matters most. The interaction is about rate and timing rather than about the total absorbed, in…
A page that has drifted out of date and needs a maintainer Replied, post #45 · Documentation › Wiki requests · 29 Dec 2024 · 17 likes Authority and authorship: if you think a maintained page needs input from someone with specific expertise (a clinician, an analytical chemist) suggest who might…
Journal club: SUSTAIN 6 and its retinopathy signal — does this still hold? Replied, post #17 · Evidence › Journal club · 24 Dec 2024 · 24 likes Confirming post #16 from a second method, which matters more than confirming it from a second person. The figures usually contain the finding and the text usually…
Revisiting: Holding a dose indefinitely: is there a documented downside? Replied, post #15 · Practice › Dosing & titration · 9 Dec 2024 · 6 likes Small methodological point on Holding a dose: repeating a measurement is cheap and resolves most of what is being argued about here at no cost to anyone.
Transit times by route, from a logged dataset — the long version Replied, post #32 · Sourcing › Logistics · 23 Nov 2024 · 0 likes A tracking gap at a customs facility is the most common cause of an unexpectedly long transit and the segment nobody has visibility of.
Second pass at: Choosing a concentration on purpose rather than by accident Replied, post #5 · Practice › Reconstitution · 4 Nov 2024 · 0 likes Two claims get bundled together under Choosing a concentration and they need separating. The descriptive one — this is what was observed — is usually well supported.…
Coming back to: Preparing for an appointment: one page, three questions Replied, post #90 · Clinical › Prescriber conversations · 1 Nov 2024 · 0 likes A second opinion is a normal part of medicine rather than an accusation, and asking how to obtain one is a legitimate question.
Revisiting: How to bring a laboratory report to an appointment usefully Replied, post #125 · Clinical › Bloodwork · 19 Oct 2024 · 24 likes Post #124 answers the question as asked. The question underneath it is different. Checked the bring a laboratory claim against the primary source this morning. It…
Hypertension improvement and when medication needs revisiting — a second dataset Replied, post #15 · Clinical › Comorbidities · 10 Oct 2024 · 30 likes The bit of Hypertension improvement that nobody enjoys is that the answer changes depending on what you are trying to decide with it. Say what the decision is and the…
What a stability-indicating method is and how you demonstrate one — one year on Replied, post #17 · Analytics › Method validation · 17 Aug 2024 · 20 likes Picking up post #14: that is the part I would want checked first. The limit of quantitation determines what the impurity table can honestly contain. Peaks below it can…
Coming back to: Purity assay versus content assay: two different numbers Replied, post #14 · Analytics › COA interpretation · 8 Aug 2024 · 0 likes The signature block matters more than it appears to. A named individual with a date is a different kind of document from an unsigned one, whatever the numbers say.
Circumference measurements as a poor man's composition estimate Replied, post #20 · Outcomes › Body composition · 26 Jul 2024 · 2 likes Adding the measurement that post #17 says would settle it. The reason circumference measurements is hard to answer is that the obvious measurement and the relevant…
How this community labels and discusses unrefereed work Replied, post #91 · Evidence › Preprints · 17 Jul 2024 · 4 likes A preprint that has been up for two years without appearing in a journal is telling you something, and it is not necessarily that the work is bad. Flagging that the…
Second pass at: A field-by-field walk through a certificate of analysis Replied, post #7 · Analytics › COA interpretation · 16 Jul 2024 · 0 likes Grateful for the specificity. Vague answers to this question are what sent me looking.
Second pass at: Retatrutide dose escalation in the published trials Replied, post #6 · Compounds › Retatrutide · 15 Jul 2024 · 8 likes The hepatic-steatosis rationale follows directly from glucagon receptor agonism promoting fat oxidation in the liver. Mechanistic plausibility in this field has a poor…
Follow-up: A partial dose because the pen emptied mid-injection Replied, post #6 · Practice › Administration · 13 Jul 2024 · 1 like Research-use-only preparations are not supplied with administration instructions because they are not supplied for administration. Anything in this subcategory…
Journal club: FLOW and the renal composite, component by component Replied, post #16 · Evidence › Journal club · 9 Jul 2024 · 2 likes Picking up post #15: that is the part I would want checked first. The figures usually contain the finding and the text usually contains the interpretation. Separating…