j.sorensen

TL2 Moderator · 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 Seasonal patterns: some people report weight loss is slower in winter than summer. Body composition and activity changes might contribute. Noting the season is useful…
What is genuinely unknown about long-term amylin agonism Replied, post #83 · Compounds › Cagrilintide & amylin analogues · 25 Jul 2026 · 20 likes This follows post #80 rather than contradicting it. I disagree with the reply above, and I think the disagreement is substantive rather than terminological. The…
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 This follows post #93 rather than contradicting it. The FAQ link in the sidebar is maintained and worth ten hours of forum browsing. It is not comprehensive but it is…
Revisiting: Protein density versus volume when you cannot eat much Replied, post #65 · Nutrition & Training › Protein & intake · 14 Jul 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…
Seven-day rolling means and why weekly readings mislead Replied, post #30 · Outcomes › Progress reports · 14 Jul 2026 · 6 likes post #29 is right about the mechanism and I think understates the practical bit. Plateaus and resets: if weight loss stalls and then resumes, that is ordinary. It is…
Alcohol: what is documented and what is folklore Replied, post #110 · Practice › Interactions · 14 Jul 2026 · 14 likes post #109 is right about the mechanism and I think understates the practical bit. Food interactions: most interactions are absorption interactions. Some medications…
Secretagogues and glucose tolerance: the mechanistic concern Replied, post #62 · Compounds › Secretagogues & GH axis · 5 Jul 2026 · 14 likes Tesamorelin has an approved indication in HIV-associated lipodystrophy. That is the only compound in this class with a registration-quality evidence base from a proper…
Follow-up: Prior authorisation: what the criteria usually require Replied, post #45 · Access › Insurance & coverage · 29 Jun 2026 · 3 likes Having read the exchange above, I think I was wrong earlier in this topic and I want to say so plainly rather than quietly editing. The correction was fair and I had…
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 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…
Revisiting: Journal club: SURMOUNT-OSA and a hard endpoint in a soft field Replied, post #47 · Evidence › Journal club · 20 Jun 2026 · 0 likes STEP 1 (N Engl J Med 2021): The pivotal obesity trial for semaglutide and the reference point for most subsequent comparison. Mean weight reduction was substantially…
Aggregate verification data across the directory, with caveats Replied, post #4 · Sourcing › Independent verification · 19 Jun 2026 · 8 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…
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 This follows post #47 rather than contradicting it. Feature requests: if the site would work better with a feature it does not have (better search, different filtering,…
Area percent versus weight percent: the confusion that causes most arguments Replied, post #14 · Analytics › HPLC & UHPLC · 5 Jun 2026 · 1 like post #13 is right about the mechanism and I think understates the practical bit. For anyone arriving from a search: the marked solution above is the direct answer, and…
Rotating between abdomen, thigh and upper arm: absorption differences — one year on Replied, post #60 · Practice › Administration · 10 May 2026 · 0 likes Angle of injection: 90 degrees into pinched tissue ensures subcutaneous placement. It is not always necessary and shallower angles can work, but 90 degrees into a small…
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 Area percent is not mass percent. It is a proportion of absorbance, weighted by each species' extinction coefficient. For closely related impurities the approximation…
Reading a home test result without over-claiming Replied, post #23 · Analytics › Home & field testing · 26 Apr 2026 · 0 likes Worth separating two things that post #19 runs together. False positives and false negatives: no test has 100% sensitivity and 100% specificity. A negative result does…
A plateau that disappeared when I changed how I measured — the long version Replied, post #29 · Outcomes › Progress reports · 21 Apr 2026 · 7 likes I read post #27 twice before replying, because I had assumed the opposite. Menstrual cycle: for people who menstruate, weight can shift by several pounds across the…
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. A documentation…
Journal club: is percentage weight change the right endpoint? Replied, post #73 · Evidence › Journal club · 16 Apr 2026 · 9 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…
Spike-and-recover accuracy for a peptide assay Replied, post #108 · Analytics › Method validation · 10 Apr 2026 · 3 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…
Coming back to: Training through a dose escalation week Replied, post #70 · Nutrition & Training › Resistance training · 4 Apr 2026 · 0 likes Post-weight-loss training: once weight loss is complete and energy deficit ends, training can shift to building again. The transition from preservation mode to building…
Injection discomfort: needle gauge, volume, temperature, technique Replied, post #46 · Practice › Administration · 2 Apr 2026 · 12 likes Air bubbles in a subcutaneous injection: the honest risk assessment is low. Tiny air bubbles in subcutaneous tissue do not behave like an air embolism in a blood…
Coming back to: Washout: how long is long enough, and for what purpose Replied, post #69 · Pharmacology › Pharmacokinetics · 13 Mar 2026 · 8 likes Hepatic metabolism: the degree to which each compound is hepatically metabolised versus renally cleared is known but varies. Severe liver disease changes clearance.
Introducing myself: pharmacist, sceptic, reluctant participant — one year on Replied, post #44 · Lounge › Introductions · 12 Mar 2026 · 11 likes No spam: introductions are not a place to advertise commercial products or services. That is a rules violation.
Coming back to: Semaglutide in people without diabetes: what the evidence base looks like Replied, post #35 · Compounds › Semaglutide · 24 Feb 2026 · 8 likes Gastric emptying delay is the mechanism behind most of the gastrointestinal side effects. Slowing the stomach empties it feeds less food into the intestines at a time,…
Gastro-oesophageal reflux: improving or worsening? Replied, post #21 · Clinical › Comorbidities · 22 Feb 2026 · 3 likes Coming back to post #19, because the follow-up matters more than the original answer. Two things before anyone answers the substance. First, the context in the first…
Mass error in ppm: the arithmetic and the caveat Replied, post #86 · Analytics › Mass spectrometry · 15 Feb 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…
Anaesthesia and elective surgery: the aspiration question Replied, post #12 · Practice › Interactions · 3 Feb 2026 · 0 likes Insulin interaction: semaglutide and tirzepatide are not contraindicated with insulin but the combination carries hypoglycemia risk if insulin doses are not adjusted.…
Trifluoroacetate content and its consequences Replied, post #58 · Analytics › Impurities & related substances · 1 Feb 2026 · 12 likes On post #54 — agreed on the reasoning, with one qualification. Deamidation at asparagine and glutamine: adds 1 approximately. Frequently appears as a close-eluting…
Revisiting: A page that has drifted out of date and needs a maintainer Replied, post #36 · Documentation › Wiki requests · 13 Jan 2026 · 6 likes Translation suggestions: if a maintained page should exist in another language, suggesting it here helps the maintainers prioritise multilingual work.
[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. Reading a rodent study on a secretagogue without over-extrapolating: rodent studies can…
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 Blinding: blinding yourself (not knowing which condition you are in) removes expectation bias. This is hard to do with these compounds (the appetite suppression is hard…
Why tirzepatide titration schedules have more steps than semaglutide's Replied, post #5 · Compounds › Tirzepatide · 16 Dec 2025 · 27 likes This follows post #2 rather than contradicting it. Titration schedules for tirzepatide have more dose steps than semaglutide partly because the compound is more potent…
Where to report an adverse event officially, by region — a second dataset Replied, post #60 · Safety › Adverse events · 27 Oct 2025 · 0 likes post #59 is right about the mechanism and I think understates the practical bit. Pancreatitis is a genuine serious adverse event to know: severe epigastric pain, back…
Availability by country, dated, with primary sources Replied, post #32 · Access › International · 24 Oct 2025 · 0 likes Import rules for personal use: what you can import for personal use depends on your country's rules, not on where it is sold. Checking your country's rules before…
New subcategory: rationale and scope Replied, post #54 · Meta › Announcements · 18 Oct 2025 · 1 like Archives: older announcements are archived by date. Checking archives is useful if you want to know what changed when.
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 There is no stupid-questions rule and no penalty for asking badly. The response to a poorly framed question is a request for clarification, not rudeness. That is a…
Reading SURMOUNT-1 without the press release Replied, post #17 · Compounds › Tirzepatide · 25 Sep 2025 · 31 likes Worth separating two things that post #13 runs together. SURPASS-2 compared tirzepatide with semaglutide 1.0 mg, the licensed diabetes dose at that time. It did not…
About the Mental health category Replied, post #5 · Wellbeing › Mental health · 24 Sep 2025 · 7 likes Identity and self-image: for some people, weight and body size are central to identity. Large change to body size can affect identity. This is not pathological; it is…
A ten-fold dose error caught before injection Replied, post #103 · Devices › Syringes & needles · 20 Sep 2025 · 16 likes Fixed versus detachable needles: insulin syringes usually have fixed needles (no dead volume loss to the hub). Luer-lock syringes use detachable needles (more dead…
Second pass at: Triple agonism: additive, synergistic, or neither? Replied, post #101 · Compounds › Retatrutide · 26 Aug 2025 · 0 likes Triple agonism: is the effect additive, synergistic, or neither? A phase 2 comparison of tirzepatide (dual) to retatrutide (triple) would answer that question. The…
[2026 update] Cardiovascular risk: reading the outcome trials as a set Replied, post #98 · Clinical › Comorbidities · 22 Aug 2025 · 0 likes Hepatic steatosis and MASH: a phase 2 trial in semaglutide for steatohepatitis showed resolution was more frequent on treatment. Histological resolution is a surrogate…
Hepatic impairment and the absence of data Replied, post #17 · Clinical › Special populations · 22 Aug 2025 · 0 likes Renal impairment: the compounds are cleared renally to some degree. Dose adjustments might be needed in severe renal impairment. Consulting with a clinician familiar…
Second pass at: Why this subcategory is stricter about sourcing than most Replied, post #86 · Compounds › Secretagogues & GH axis · 21 Aug 2025 · 7 likes Development history is more informative than speculation: ipamorelin was investigated clinically for post-operative ileus and was not taken forward to registration.…
The "under review" status pill and when a moderator applies it — a second dataset Replied, post #14 · Evidence › Preprints · 15 Aug 2025 · 9 likes Check whether it was later published: searching for the preprint's first author and keywords in PubMed might find a published version. The published version is the…
Documentation that appears only after payment Replied, post #5 · Sourcing › Red flags · 14 Aug 2025 · 4 likes Unresponsiveness: a supplier that does not reply to reasonable requests for documentation or clarification is showing you something about how they operate.
A ten-fold dose error caught before injection — one year on Replied, post #138 · Devices › Syringes & needles · 5 Aug 2025 · 0 likes Needle length: typical lengths for subcutaneous injection are 4-6 mm (short), 8 mm (standard), or 10-12 mm (longer). Longer needles are needed for deeper tissue or if…
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 This follows post #26 rather than contradicting it. For anyone arriving from a search: the marked solution above is the direct answer, and the replies underneath it add…
Counter-ion content and its effect on measured mass Replied, post #105 · Analytics › Mass spectrometry · 28 Jul 2025 · 0 likes I read post #103 twice before replying, because I had assumed the opposite. What mass accuracy establishes: the measured mass is consistent with a specific composition.…
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 On post #2 — agreed on the reasoning, with one qualification. Is synergy the right word for the combination data? A phase 2 trial cannot establish whether effects are…
[2026 update] Splitting an overlong document into two Replied, post #13 · Documentation › Wiki requests · 29 Jun 2025 · 0 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…
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. Multiple services on one lot: agreement across two independent laboratories is…
Sequence verification for an obscure compound: how it is done Replied, post #71 · Compounds › Other compounds · 23 Jun 2025 · 20 likes Picking up post #68: that is the part I would want checked first. Reading a supplier's product description as a marketing document: that is exactly what it is. The…
Revisiting: What to include when your question involves arithmetic Replied, post #4 · Start Here › How to Ask · 21 Jun 2025 · 0 likes Five questions in one post gets you one answer: the easiest one, usually not the one you needed most. Post them separately or pick the one that depends on the others…
Why the timeline is on the right and not the left Replied, post #26 · Meta › Site feedback · 7 Jun 2025 · 2 likes Coming back to post #24, because the follow-up matters more than the original answer. Navigation problems: if you cannot find something you expected to exist, or the…
Domestic fridge temperature mapping: a cheap experiment — what changed since Replied, post #118 · Devices › Cold chain · 7 Jun 2025 · 4 likes Temperature logging: devices that record temperature over time let you confirm cold chain was maintained. Useful if a shipment was delayed or if you are concerned about…
Reading a trial's population section before its results — does this still hold? Replied, post #121 · Evidence › Trials · 19 May 2025 · 31 likes This follows post #118 rather than contradicting it. The estimand: what the trial set out to estimate. Two trials can be identical in structure but estimate different…
Telehealth prescribing models in the US Replied, post #95 · Regional › North America · 7 May 2025 · 11 likes post #94 answers the question as asked. The question underneath it is different. Regional variation in North America: access differs substantially by US state and…
[2026 update] Building a sensible monitoring schedule with your prescriber Replied, post #15 · Clinical › Bloodwork · 5 May 2025 · 12 likes Time of day: some biomarkers vary across the day. Cortisol in the morning differs from cortisol in the evening. Comparing results from different times of day is…
An appeal that failed, and what I would do differently Replied, post #2 · Access › Insurance & coverage · 16 Apr 2025 · 0 likes Formulary status: the list of covered medications and the tier (how much you pay) they are on. Checking the current formulary before going to a clinic appointment saves…
Criticising the method without criticising the authors Replied, post #55 · Evidence › Study critique · 12 Apr 2025 · 0 likes post #54 is right about the mechanism and I think understates the practical bit. Choosing the worst interpretation: "The confidence interval includes a harmful effect"…
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. Promoted topic withdrawal: if a promoted topic becomes outdated or inaccurate and the maintainer does not update,…
Why pulsatile secretion matters for interpreting secretagogue claims — a second dataset Replied, post #52 · Compounds › Secretagogues & GH axis · 20 Mar 2025 · 8 likes What a well-designed human trial of a secretagogue would look like: randomised, placebo-controlled, adequate sample size, IGF-1 as primary outcome, muscle and strength…
Reading order for a first week here, and what to skip until later Replied, post #41 · Start Here › Welcome · 17 Mar 2025 · 30 likes Coming back to post #39, because the follow-up matters more than the original answer. On the reading order question specifically: start with the how-to-ask materials in…
Airline travel with a temperature-sensitive injectable — what changed since Replied, post #6 · Devices › Cold chain · 5 Mar 2025 · 0 likes post #5 is right about the mechanism and I think understates the practical bit. Light protection: avoid direct sunlight and UV exposure. Amber vials or opaque…
Why mass spectrometry cannot tell you about an epimer Replied, post #70 · Analytics › Mass spectrometry · 26 Feb 2025 · 22 likes Calibration matters: a high-resolution instrument out of calibration can report mass with ppm error large enough to be uninformative. Check when the instrument was last…
What we do not know about retatrutide, listed explicitly Replied, post #112 · Compounds › Retatrutide · 26 Feb 2025 · 1 like Phase 2 sample sizes are not adequate for safety characterisation of a novel triple agonist. Phase 3 is where that question gets answered. Using phase 2 results to make…
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 Water content (residual moisture) matters: lyophilised peptide is not dry. A few percent water is normal. The difference between a TFA salt and an acetate salt can be…
Protein density versus volume when you cannot eat much Replied, post #76 · Nutrition & Training › Protein & intake · 5 Feb 2025 · 0 likes Picking up post #73: that is the part I would want checked first. Protein sources: animal sources (meat, fish, eggs, dairy) are denser and easier to hit targets with.…
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 Trust levels accumulate over time and they give you access to small things like the ability to edit your own posts without a timestamp. They are not a status symbol and…
Journal club: SURMOUNT-1, read without the press release Replied, post #42 · Evidence › Journal club · 12 Jan 2025 · 15 likes SELECT (N Engl J Med 2023): Semaglutide cardiovascular outcomes without diabetes. The first outcome trial in people without diabetes, which decoupled the cardiovascular…
Body image changing more slowly than the body Replied, post #96 · Wellbeing › Mental health · 22 Dec 2024 · 6 likes Social and relationship impacts: weight change affects how others perceive and interact with a person. Those impacts are real and can be psychologically significant.
Body image changing more slowly than the body Replied, post #75 · Wellbeing › Mental health · 19 Dec 2024 · 0 likes post #74 answers the question as asked. The question underneath it is different. Disordered eating history: a history of anorexia, bulimia, or other eating disorders…
Persistent vomiting and the threshold for seeking help — one year on Replied, post #6 · Safety › Adverse events · 18 Dec 2024 · 22 likes Allergic reactions: true allergy (anaphylaxis, severe rash) is rare with these peptide compounds but possible. Distinguishing true allergy from GI intolerance matters.
Promotion criteria, and the one that stops most nominations Replied, post #142 · Documentation › Doc review · 16 Dec 2024 · 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…
Type 1 diabetes: off-label use and the evidence gap — what changed since Replied, post #23 · Clinical › Special populations · 21 Nov 2024 · 31 likes Renal impairment: the compounds are cleared renally to some degree. Dose adjustments might be needed in severe renal impairment. Consulting with a clinician familiar…
EMA product information as a primary source — does this still hold? Replied, post #96 · Regional › European Union · 17 Nov 2024 · 14 likes Coming back to post #94, because the follow-up matters more than the original answer. Cross-border purchase rules: buying a prescription in one EU country and bringing…
EMA product information as a primary source — does this still hold? Replied, post #75 · Regional › European Union · 17 Nov 2024 · 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…
Why "any advice?" is the least effective ending for a post Replied, post #26 · Start Here › How to Ask · 11 Nov 2024 · 0 likes This follows post #23 rather than contradicting it. The specific question in the title is more useful than you might think. A title like "a question I have" forces the…
Transporting a vial for a weekend away Replied, post #14 · Practice › Storage & stability · 28 Oct 2024 · 0 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: Buffers, pH and why a formulation is a formulation Replied, post #10 · Pharmacology › Formulation chemistry · 22 Oct 2024 · 23 likes post #9 answers the question as asked. The question underneath it is different. Antioxidants: compounds that prevent oxidation (which damages peptides) are sometimes…
Progressive overload when the scale is falling — one year on Replied, post #130 · Nutrition & Training › Resistance training · 6 Oct 2024 · 0 likes Recovery: heavier training on a energy deficit and on a compound that slows gastric emptying requires attention to recovery (sleep, nutrition, stress). Recovery…
Second pass at: A field-by-field walk through a certificate of analysis Replied, post #71 · Analytics › COA interpretation · 1 Oct 2024 · 12 likes This follows post #68 rather than contradicting it. What fields matter on a certificate: lot number matching the vial, test date, the analytical method stated…
Tracking a preprint to publication: a worked example — the long version Replied, post #36 · Evidence › Preprints · 11 Sep 2024 · 8 likes How to cite a preprint: author last name, first initial, et al. Title. Server name [preprint]. Posted date. Doi. Include the server name and note that it is a preprint.
Guidelines revision: what changed and why Replied, post #141 · Meta › Announcements · 29 Jul 2024 · 30 likes post #140 answers the question as asked. The question underneath it is different. Notifications: watching this subcategory means you receive notifications when…
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. A logistics question, since the…