j.sorensen

TL2 · Rosario

Contributes reviews on supplier material. Based in Rosario.

Joined 5 January 2025 · last posted 1d

87 posts, newest first. Showing up to 150.

Seven-day rolling means and why weekly readings mislead Replied, post #121 · Outcomes › Progress reports · 27 Jul 2026 · 1 like State the method before the numbers. Same scale, same time of day, same conditions — without that a series is a collection of readings rather than a measurement. It is…
What is genuinely unknown about long-term amylin agonism Replied, post #83 · Compounds › Cagrilintide & amylin analogues · 25 Jul 2026 · 20 likes Post #80 is the version of this I will quote in future. One addition. Cagrilintide is a long-acting amylin analogue, which puts it in a different mechanistic family…
I joined for one answer and stayed for a year — what changed my mind Replied, post #96 · Start Here › Welcome · 20 Jul 2026 · 6 likes If you are not sure which subcategory a question belongs in, post it in the closest one. A moderator will move it, the move is logged, and nothing bad happens to you.
Revisiting: Protein density versus volume when you cannot eat much Replied, post #65 · Nutrition & Training › Protein & intake · 14 Jul 2026 · 0 likes What I would check first on Protein density versus volume is whether the thing being measured moved or whether the way of measuring it moved. Those look identical in a…
Seven-day rolling means and why weekly readings mislead Replied, post #30 · Outcomes › Progress reports · 14 Jul 2026 · 6 likes Post #29 answers the question as asked. The question underneath it is different. State the method before the numbers. Same scale, same time of day, same conditions —…
Alcohol: what is documented and what is folklore Replied, post #110 · Practice › Interactions · 14 Jul 2026 · 14 likes Picking up post #109: that is the part I would want checked first. The thing about alcohol that took me longest to accept is that a plausible mechanism is not evidence…
Secretagogues and glucose tolerance: the mechanistic concern Replied, post #62 · Compounds › Secretagogues & GH axis · 5 Jul 2026 · 14 likes Research-use-only secretagogues are not approved for human use. That statement is doing real work in this subcategory, where the published evidence base is thinner than…
Follow-up: Prior authorisation: what the criteria usually require Replied, post #45 · Access › Insurance & coverage · 29 Jun 2026 · 3 likes Genuine question rather than a rhetorical one: has anyone here actually observed Prior authorisation, as opposed to read about it? The thread is long and I cannot tell.
Vomiting: when it is expected and when it is a reason to stop — one year on Replied, post #17 · Practice › Side effects · 26 Jun 2026 · 0 likes The relationship between symptom burden and outcome is not what people assume. Feeling worse is not evidence of a larger effect and feeling nothing is not evidence of…
Revisiting: Journal club: SURMOUNT-OSA and a hard endpoint in a soft field Replied, post #47 · Evidence › Journal club · 20 Jun 2026 · 0 likes A definition problem is doing most of the work in this SURMOUNT-OSA discussion. Once the term is pinned down I suspect the disagreement mostly goes away and what is…
Aggregate verification data across the directory, with caveats Replied, post #4 · Sourcing › Independent verification · 19 Jun 2026 · 8 likes The thing about aggregate verification data that took me longest to accept is that a plausible mechanism is not evidence of an effect. It is a reason to look, not a…
Muscle cramps: the ordinary causes before the exotic ones — a second dataset Started this topic · Practice › Side effects · 15 Jun 2026 · 15 likes Posting this under the heading it deserves: Muscle cramps: the ordinary causes before the exotic ones — a second dataset Everything below is what sits behind that.…
Why the timeline is on the right and not the left — what changed since Replied, post #50 · Meta › Site feedback · 7 Jun 2026 · 13 likes Adding the measurement that post #47 says would settle it. Reporting a real defect: on a long topic the jump-to-post link scrolls to the right post but the highlight…
Area percent versus weight percent: the confusion that causes most arguments Replied, post #14 · Analytics › HPLC & UHPLC · 5 Jun 2026 · 1 like Confirming post #13 from a second method, which matters more than confirming it from a second person. Before anything else: what was the gradient, and at what…
Rotating between abdomen, thigh and upper arm: absorption differences — one year on Replied, post #60 · Practice › Administration · 10 May 2026 · 0 likes My position on Rotating between abdomen is current rather than settled. I have revised it once already and I expect to again, so treat it accordingly.
Why 99.2% and 97.8% on the same lot can both be correct Replied, post #3 · Analytics › HPLC & UHPLC · 8 May 2026 · 1 like Two things can be true about 99.2% and 97.8% at once: the mechanism is plausible and the evidence for the size of the effect is thin. Most of the argument here is…
Reading a home test result without over-claiming Replied, post #23 · Analytics › Home & field testing · 26 Apr 2026 · 0 likes On post #19 — agreed on the reasoning, with one qualification. Documenting home checks with dates and lots makes them accumulate into something. Undocumented ones…
A plateau that disappeared when I changed how I measured — the long version Replied, post #29 · Outcomes › Progress reports · 21 Apr 2026 · 7 likes Post #27 describes the usual case. This is about the unusual one. Rate of change matters more than the absolute number for most of the questions people ask about their…
Endotoxin and why it is a separate question from purity — what changed since Started this topic · Analytics › Impurities & related substances · 16 Apr 2026 · 0 likes On the subject in the title: Endotoxin and why it is a separate question from purity — what changed since Working notes rather than a conclusion. What changes if the…
Journal club: is percentage weight change the right endpoint? Replied, post #73 · Evidence › Journal club · 16 Apr 2026 · 9 likes The baseline characteristics table is the single most useful page for the questions that get asked here, because it tells you who the result applies to.
Spike-and-recover accuracy for a peptide assay Replied, post #108 · Analytics › Method validation · 10 Apr 2026 · 3 likes The limit of quantitation determines what the impurity table can honestly contain. Peaks below it can be reported as detected and cannot be reported as a number. I have…
Coming back to: Training through a dose escalation week Replied, post #70 · Nutrition & Training › Resistance training · 4 Apr 2026 · 0 likes Training fasted or fed is a comfort question at these intakes rather than a performance question for most people.
Injection discomfort: needle gauge, volume, temperature, technique Replied, post #46 · Practice › Administration · 2 Apr 2026 · 12 likes Leaving the needle in for a couple of seconds after depressing the plunger reduces leakage at the site. It costs nothing and it is the fix for the "some came back out"…
Coming back to: Washout: how long is long enough, and for what purpose Replied, post #69 · Pharmacology › Pharmacokinetics · 13 Mar 2026 · 8 likes Volume of distribution: the theoretical volume the drug distributes into. For albumin-binding compounds, volume is reduced compared to drugs that do not bind protein.…
Introducing myself: pharmacist, sceptic, reluctant participant — one year on Replied, post #44 · Lounge › Introductions · 12 Mar 2026 · 11 likes Welcome: the response to introductions is usually welcome. People will reply to introduce themselves back or to let you know they are glad you are here. Posting it…
Coming back to: Semaglutide in people without diabetes: what the evidence base looks like Replied, post #35 · Compounds › Semaglutide · 24 Feb 2026 · 8 likes STEP 1 and STEP 4 are two different questions. The first asks what happens when treatment is added; the second asks what happens when it is withdrawn after a run-in.…
Gastro-oesophageal reflux: improving or worsening? Replied, post #21 · Clinical › Comorbidities · 22 Feb 2026 · 3 likes Post #19 and I disagree about the size of the effect, not about the direction. Gastrointestinal conditions interact with a mechanism that slows gastric emptying in ways…
Mass error in ppm: the arithmetic and the caveat Replied, post #86 · Analytics › Mass spectrometry · 15 Feb 2026 · 0 likes The honest summary of what a mass result buys you: it narrows the field of what the material could be, considerably. It never closes it, and no certificate should be…
Anaesthesia and elective surgery: the aspiration question Replied, post #12 · Practice › Interactions · 3 Feb 2026 · 0 likes The most defensible general position in this subcategory: identify the plausible mechanism, check whether it has been studied, and where it has not, say that rather…
Trifluoroacetate content and its consequences Replied, post #58 · Analytics › Impurities & related substances · 1 Feb 2026 · 12 likes Coming back to post #54, because the follow-up matters more than the original answer. What I would tell a new member reading about trifluoroacetate content for the…
Revisiting: A page that has drifted out of date and needs a maintainer Replied, post #36 · Documentation › Wiki requests · 13 Jan 2026 · 6 likes Documents that are mostly a worked example age better than documents that are mostly a summary, because the arithmetic does not change.
[2026 update] Evidence quality in the secretagogue literature: an honest assessment Replied, post #9 · Compounds › Secretagogues & GH axis · 10 Jan 2026 · 6 likes Post #8 answers the question as asked. The question underneath it is different. Why this subcategory is stricter about sourcing than most: the evidence base is weaker…
Coming back to: Why most self-reports here are not experiments, and that is fine Replied, post #32 · Research Methods › N-of-1 designs · 31 Dec 2025 · 3 likes It does not tell you about anybody else, which is why aggregating these accounts does not produce evidence of the kind people want it to. The mechanism is plausible,…
Why tirzepatide titration schedules have more steps than semaglutide's Replied, post #5 · Compounds › Tirzepatide · 16 Dec 2025 · 27 likes Post #2 is the version of this I will quote in future. One addition. SURPASS-2 compared tirzepatide with semaglutide 1.0 mg, the licensed diabetes dose at that time. It…
Where to report an adverse event officially, by region — a second dataset Replied, post #60 · Safety › Adverse events · 27 Oct 2025 · 0 likes The arithmetic in post #59 is right; the assumption feeding it is the part to check. The most useful contribution to this subcategory is a completed account: what…
Availability by country, dated, with primary sources Replied, post #32 · Access › International · 24 Oct 2025 · 0 likes I came in to disagree and I am leaving without a disagreement.
New subcategory: rationale and scope Replied, post #54 · Meta › Announcements · 18 Oct 2025 · 1 like New subcategory is a question about a distribution, not about a value, and treating it as a value is what produces the confident wrong answers.
What happens after your first post: likes, trust levels, and why none of it matters much… Replied, post #23 · Start Here › Welcome · 14 Oct 2025 · 19 likes Introducing yourself is fine and requires no question. Post in this subcategory, describe the context that matters for why you are here, and lurk for a bit before…
Reading SURMOUNT-1 without the press release Replied, post #17 · Compounds › Tirzepatide · 25 Sep 2025 · 31 likes Nothing to add, except that this is the answer I would give if asked.
About the Mental health category Replied, post #5 · Wellbeing › Mental health · 24 Sep 2025 · 7 likes That is the distinction I keep failing to hold on to. Written down now.
A ten-fold dose error caught before injection Replied, post #103 · Devices › Syringes & needles · 20 Sep 2025 · 16 likes What I would tell a new member reading about ten-fold dose error caught for the first time: the confident posts are not the reliable ones, and the reliable ones are…
Second pass at: Triple agonism: additive, synergistic, or neither? Replied, post #101 · Compounds › Retatrutide · 26 Aug 2025 · 0 likes This is the first time the answer has come with its own limits attached. Appreciated.
[2026 update] Cardiovascular risk: reading the outcome trials as a set Replied, post #98 · Clinical › Comorbidities · 22 Aug 2025 · 0 likes Cardiovascular risk has been discussed here with more heat than it deserves, mostly because two definitions have been in play the whole time.
Hepatic impairment and the absence of data Replied, post #17 · Clinical › Special populations · 22 Aug 2025 · 0 likes Adding a note of thanks rather than an opinion. I did not know most of that.
Second pass at: Why this subcategory is stricter about sourcing than most Replied, post #86 · Compounds › Secretagogues & GH axis · 21 Aug 2025 · 7 likes On analysis: these are short peptides and generally straightforward chromatographically, which means a poor purity result is more likely to reflect the synthesis than…
The "under review" status pill and when a moderator applies it — a second dataset Replied, post #14 · Evidence › Preprints · 15 Aug 2025 · 9 likes That matches what I have seen, for whatever a single anecdote is worth.
Documentation that appears only after payment Replied, post #5 · Sourcing › Red flags · 14 Aug 2025 · 4 likes Summarising the documentation thread so far, since it is long and the answer is buried: the first reply has the method, the fourth has the correction to it, and the…
A ten-fold dose error caught before injection — one year on Replied, post #138 · Devices › Syringes & needles · 5 Aug 2025 · 0 likes Barrel size determines resolution and nothing else. A 0.3 mL barrel and a 1 mL barrel deliver the same volume equally well; the smaller one lets you see what you are…
A checklist for reading a certificate in under two minutes — does this still hold? Replied, post #29 · Analytics › COA interpretation · 3 Aug 2025 · 23 likes Taking post #27 at face value and following it one step further. The distinction between release testing and characterisation is one industrial documents make and…
Counter-ion content and its effect on measured mass Replied, post #105 · Analytics › Mass spectrometry · 28 Jul 2025 · 0 likes Coming back to post #103, because the follow-up matters more than the original answer. The strongest argument against my own position on counter-ion content, stated as…
Coming back to: Nausea profile of amylin analogues compared with GLP-1 agonists Replied, post #6 · Compounds › Cagrilintide & amylin analogues · 5 Jul 2025 · 9 likes Post #2 and I disagree about the size of the effect, not about the direction. I read the earlier replies on Nausea profile of amylin analogues twice before writing…
[2026 update] Splitting an overlong document into two Replied, post #13 · Documentation › Wiki requests · 29 Jun 2025 · 0 likes Two sentences on Splitting an overlong document and then I will stop, because the rest is speculation and the thread is better without mine. What is documented is…
A report I filed that turned out to be wrong, and the correction Replied, post #123 · Sourcing › Vendor reports · 26 Jun 2025 · 9 likes Post #122 is right about the mechanism and I think understates the practical bit. The cost of a submission is worth stating. It is the main reason people do not do this…
Sequence verification for an obscure compound: how it is done Replied, post #71 · Compounds › Other compounds · 23 Jun 2025 · 20 likes Taking post #68 at face value and following it one step further. Where a compound has a legitimate pharmaceutical form somewhere in the world, the labelling for that…
Revisiting: What to include when your question involves arithmetic Replied, post #4 · Start Here › How to Ask · 21 Jun 2025 · 0 likes If the answer you got does not fit your case, say which part does not fit rather than restating the question. Otherwise the next reply is the same as the last one. Not…
Why the timeline is on the right and not the left Replied, post #26 · Meta › Site feedback · 7 Jun 2025 · 2 likes I read post #24 twice before replying, because I had assumed the opposite. If you are new and reading this thread for the answer to timeline: the answer is conditional,…
Domestic fridge temperature mapping: a cheap experiment — what changed since Replied, post #118 · Devices › Cold chain · 7 Jun 2025 · 4 likes Something worth flagging about Domestic fridge temperature mapping: the strongest-sounding claims in this thread are the ones with no source attached, which is the…
Reading a trial's population section before its results — does this still hold? Replied, post #121 · Evidence › Trials · 19 May 2025 · 31 likes Acknowledging rather than arguing. The reasoning holds as far as I can follow it.
Telehealth prescribing models in the US Replied, post #95 · Regional › North America · 7 May 2025 · 11 likes Post #94 is the version of this I will quote in future. One addition. Telehealth prescribing models is worth one more sentence than it usually gets, and the sentence is…
[2026 update] Building a sensible monitoring schedule with your prescriber Replied, post #15 · Clinical › Bloodwork · 5 May 2025 · 12 likes Repeat before acting is standard practice for an isolated abnormal result on most analytes, and it is standard for a reason. I have left out the parts I could not verify.
An appeal that failed, and what I would do differently Replied, post #2 · Access › Insurance & coverage · 16 Apr 2025 · 0 likes Taking appeal seriously for a moment rather than deflecting: the honest position is that the community has observations and no controlled comparison, and those two…
Criticising the method without criticising the authors Replied, post #55 · Evidence › Study critique · 12 Apr 2025 · 0 likes Narrowing post #53, because the general version has more than one answer. My understanding of criticising the method without criticising is a few years old and may have…
Review: a draft on reconstitution arithmetic, with objections Replied, post #82 · Documentation › Doc review · 30 Mar 2025 · 11 likes This follows post #79 rather than contradicting it. Speaking only to draft on reconstitution arithmetic as I have actually seen it, rather than as it is usually…
Why pulsatile secretion matters for interpreting secretagogue claims — a second dataset Replied, post #52 · Compounds › Secretagogues & GH axis · 20 Mar 2025 · 8 likes Taking pulsatile secretion seriously for a moment rather than deflecting: the honest position is that the community has observations and no controlled comparison, and…
Reading order for a first week here, and what to skip until later Replied, post #41 · Start Here › Welcome · 17 Mar 2025 · 30 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…
Airline travel with a temperature-sensitive injectable — what changed since Replied, post #6 · Devices › Cold chain · 5 Mar 2025 · 0 likes That is the distinction I keep failing to hold on to. Written down now.
Why mass spectrometry cannot tell you about an epimer Replied, post #70 · Analytics › Mass spectrometry · 26 Feb 2025 · 22 likes Trifluoroacetate adducts are common in material purified with TFA and are one reason a mass spectrum from a peptide can look busier than expected.
What we do not know about retatrutide, listed explicitly Replied, post #112 · Compounds › Retatrutide · 26 Feb 2025 · 1 like Nausea and vomiting were dose-related in the phase 2 work, as they are throughout this class. What is not established is whether the tolerability profile differs from…
Specification in the result column: why that is a meaningful error — the long version Replied, post #16 · Analytics › COA interpretation · 19 Feb 2025 · 25 likes The distinction between release testing and characterisation is one industrial documents make and retail ones usually do not. It is the difference between "we tested…
Protein density versus volume when you cannot eat much Replied, post #76 · Nutrition & Training › Protein & intake · 5 Feb 2025 · 0 likes The arithmetic in post #73 is right; the assumption feeding it is the part to check. Leucine and MPS: leucine stimulates muscle protein synthesis at a threshold of…
Why the Start Here categories exist, and what they are not for — one year on Replied, post #16 · Start Here › Welcome · 31 Jan 2025 · 0 likes This is the first time the answer has come with its own limits attached. Appreciated.
Journal club: SURMOUNT-1, read without the press release Replied, post #42 · Evidence › Journal club · 12 Jan 2025 · 15 likes I think the SURMOUNT-1 question is answerable and has not been answered, which is a more optimistic position than most of this thread.
Body image changing more slowly than the body Replied, post #96 · Wellbeing › Mental health · 22 Dec 2024 · 6 likes Relationship with food changing is one of the most commonly described experiences here and is discussed far less than the physical effects.
Body image changing more slowly than the body Replied, post #75 · Wellbeing › Mental health · 19 Dec 2024 · 0 likes Narrowing post #74, because the general version has more than one answer. I would keep body image and the decision it usually gets used for separate in this thread.…
Persistent vomiting and the threshold for seeking help — one year on Replied, post #6 · Safety › Adverse events · 18 Dec 2024 · 22 likes The most useful contribution to this subcategory is a completed account: what happened, what was done, and what the outcome was. Take it as a starting point and not as…
Promotion criteria, and the one that stops most nominations Replied, post #142 · Documentation › Doc review · 16 Dec 2024 · 1 like Small correction to my own earlier position on promotion criteria. I had the units the wrong way round, which changes the conclusion by an order of magnitude and…
Type 1 diabetes: off-label use and the evidence gap — what changed since Replied, post #23 · Clinical › Special populations · 21 Nov 2024 · 31 likes No disagreement from me. Posting only so the question does not look ignored.
EMA product information as a primary source — does this still hold? Replied, post #96 · Regional › European Union · 17 Nov 2024 · 14 likes On post #94 — agreed on the reasoning, with one qualification. The question underneath EMA product information is usually "how would I tell?" rather than "what is…
EMA product information as a primary source — does this still hold? Replied, post #75 · Regional › European Union · 17 Nov 2024 · 0 likes My position on EMA product information is current rather than settled. I have revised it once already and I expect to again, so treat it accordingly.
Why "any advice?" is the least effective ending for a post Replied, post #26 · Start Here › How to Ask · 11 Nov 2024 · 0 likes Confirming post #23 from a second method, which matters more than confirming it from a second person. Chromatography questions need the method before anything else:…
Transporting a vial for a weekend away Replied, post #14 · Practice › Storage & stability · 28 Oct 2024 · 0 likes Reading rather than contributing, but this is the most useful thread I have found on it.
Second pass at: Buffers, pH and why a formulation is a formulation Replied, post #10 · Pharmacology › Formulation chemistry · 22 Oct 2024 · 23 likes Picking up post #9: that is the part I would want checked first. Light sensitivity varies enormously between peptides depending on the residues present.…
Progressive overload when the scale is falling — one year on Replied, post #130 · Nutrition & Training › Resistance training · 6 Oct 2024 · 0 likes That is consistent with mine, for whatever one more account is worth.
Second pass at: A field-by-field walk through a certificate of analysis Replied, post #71 · Analytics › COA interpretation · 1 Oct 2024 · 12 likes Picking up post #68: that is the part I would want checked first. A certificate of analysis is a statement by its issuer that a defined test was performed on a defined…
Tracking a preprint to publication: a worked example — the long version Replied, post #36 · Evidence › Preprints · 11 Sep 2024 · 8 likes Sample size and pre-registration are checkable in a preprint exactly as in a paper, and they carry the same weight. Stating my assumptions rather than smuggling them in.
Guidelines revision: what changed and why Replied, post #141 · Meta › Announcements · 29 Jul 2024 · 30 likes Building on post #140 rather than restating it. Guidelines revision is a question about a distribution, not about a value, and treating it as a value is what produces…
Cold packs, phase-change material, and what survives ten days Started this topic · Sourcing › Logistics · 7 Jun 2024 · 35 likes Cold packs, phase-change material, and what survives ten days — setting out what I have, and where I think it stops being reliable. I have spent a fortnight trying to…