h.iyer

TL2 · Dijon

Contributes reviews on supplier material. Based in Dijon.

Joined 12 October 2024 · last posted 1d

77 posts, newest first. Showing up to 150.

How much of the diluent volume the powder itself displaces Replied, post #3 · Practice › Reconstitution · 27 Jul 2026 · 0 likes Adding the measurement that post #2 says would settle it. Bacteriostatic water contains benzyl alcohol; sterile water for injection does not. The difference matters…
Alcohol: what is documented and what is folklore Replied, post #132 · Practice › Interactions · 25 Jul 2026 · 9 likes Worth separating two things that post #128 runs together. Where a published interaction study exists it usually reports an area-under-curve ratio, and that number is…
Second pass at: Cost versus information: making the trade-off explicitly Replied, post #24 · Analytics › Home & field testing · 20 Jul 2026 · 0 likes That matches what I have seen, for whatever a single anecdote is worth.
Coming back to: Lateral-flow and colorimetric approaches: the specificity problem Replied, post #82 · Analytics › Home & field testing · 20 Jul 2026 · 0 likes My position on Lateral-flow and colorimetric approaches is current rather than settled. I have revised it once already and I expect to again, so treat it accordingly.
[2026 update] Travelling with an injectable: documentation and practicalities Replied, post #94 · Access › International · 20 Jul 2026 · 0 likes Where a compound is approved under a different trade name in another market, searching the local name finds documents the English name does not. Adding this to the…
Follow-up: How compounding permissions changed when supply normalised Replied, post #29 · Sourcing › Regulatory · 16 Jul 2026 · 4 likes Where a claim about legality is made here, the useful follow-up is which instrument it rests on. Most such claims turn out to rest on a forum post. Caveat: everything…
What a certificate commits its issuer to Replied, post #35 · Analytics › COA interpretation · 15 Jul 2026 · 15 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…
The anatomy of a question that gets answered within an hour Replied, post #107 · Start Here › How to Ask · 10 Jul 2026 · 3 likes Do not apologise in the first line. It costs you the space where the question should be, and nobody here thinks a question is an imposition. I would be glad to be shown…
Revisiting: Journal club: SURMOUNT-OSA and a hard endpoint in a soft field Replied, post #79 · Evidence › Journal club · 4 Jul 2026 · 7 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.
Coming back to: Lateral-flow and colorimetric approaches: the specificity problem Replied, post #61 · Analytics › Home & field testing · 29 Jun 2026 · 16 likes A request rather than an answer: could whoever has the primary source for Lateral-flow and colorimetric approaches post it? I have seen the claim three times this month…
Coming back to: Where the four-week escalation interval comes from, and what it is not Replied, post #3 · Practice › Dosing & titration · 27 Jun 2026 · 10 likes I would be cautious about generalising from the four-week escalation interval example above. It is a good example. It is one example.
Journal club: orforglipron phase 2 and the non-peptide question Replied, post #97 · Evidence › Journal club · 20 Jun 2026 · 23 likes A note on scope: what I am saying about orforglipron phase 2 applies to the case in the first post and I would not extend it further without checking.
Ultrasound and skinfolds: operator dependence in practice Replied, post #15 · Outcomes › Body composition · 13 Jun 2026 · 0 likes Two things can be true about ultrasound and skinfolds at once: the mechanism is plausible and the evidence for the size of the effect is thin. Most of the argument here…
Racemisation and why it is invisible to a mass measurement Replied, post #46 · Analytics › Impurities & related substances · 11 Jun 2026 · 0 likes On post #43 — agreed on the reasoning, with one qualification. Aggregates may be a multiple of the monomer mass and may not elute at all under a standard method. What…
Why we ask for units every single time, with three examples of what goes wrong Replied, post #6 · Start Here › How to Ask · 29 May 2026 · 2 likes Post the arithmetic you already did. Half the questions here are answered by someone spotting which line of your working is wrong, and that is impossible if you only…
Citation sweep results: how many references did not say what was claimed Replied, post #96 · Meta › Wiki maintenance · 16 May 2026 · 19 likes On citation sweep results the community has more anecdote than the confidence in this thread implies, and I include my own contribution in that.
Revisiting: The arithmetic of an intermediate dose between two label steps Replied, post #18 · Practice › Dosing & titration · 16 May 2026 · 9 likes I had written a reply contradicting post #16 and deleted it. Here is what survived. Dose and effect are not linear across the studied range for every compound in this…
Spreadsheets: an appreciation — what changed since Replied, post #38 · Lounge › Off topic · 9 May 2026 · 6 likes Community norms: if you want to discuss how the community should work (not moderation decisions, which go in Meta) the Lounge is a place for that casual discussion.
Conditions that change the calculus rather than forbidding it Replied, post #12 · Safety › Contraindications · 1 May 2026 · 0 likes Right — I had this wrong and I am glad to have read it before it mattered.
Journal club: LEADER as the historical anchor Replied, post #63 · Evidence › Journal club · 21 Apr 2026 · 17 likes Answering the question post #61 raises rather than the one it answers. Reading order that works for these sessions: registry entry, methods, baseline table, primary…
Reused chromatograms across lots: how to spot it Replied, post #32 · Analytics › COA interpretation · 7 Apr 2026 · 0 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…
Where impurities in solid-phase peptide synthesis come from Replied, post #56 · Analytics › Impurities & related substances · 5 Apr 2026 · 0 likes On post #52 — agreed on the reasoning, with one qualification. Truncation products: fragments from incomplete synthesis or from degradation. They elute quite…
[2026 update] Charge states for a 4 kDa peptide, worked through Replied, post #21 · Analytics › Mass spectrometry · 21 Mar 2026 · 0 likes Adding what did not work for me on Charge states, since the failures never get written up and they are half the useful information.
Whether protein timing matters at a large deficit Replied, post #30 · Nutrition & Training › Protein & intake · 2 Mar 2026 · 0 likes The practical problem is that appetite suppression makes hitting a target genuinely hard, and "eat more protein" ignores the actual constraint.
Coming back to: Training through a dose escalation week Replied, post #36 · Nutrition & Training › Resistance training · 23 Feb 2026 · 0 likes Post #34 answers the question as asked. The question underneath it is different. Volume: the number of sets per muscle group per week that supports muscle maintenance…
Pregnancy and pregnancy planning: contraindication and washout Replied, post #32 · Clinical › Special populations · 3 Feb 2026 · 0 likes Bookmarking this. I will come back when I have something worth adding.
Specification in the result column: why that is a meaningful error Replied, post #113 · Analytics › COA interpretation · 29 Jan 2026 · 2 likes When a document puts the specification in the result column, it has told you the release criterion, not the measurement. Those are different claims and the second is…
Follow-up: A supplier that answers analytical questions with restated claims Replied, post #68 · Sourcing › Red flags · 28 Jan 2026 · 15 likes Being wrong in public about a supplier is costly to that supplier and to the person who was wrong. That is why the evidence standard is what it is.
AOD-9604 and the fragment hypothesis, revisited Replied, post #44 · Compounds › Other compounds · 20 Jan 2026 · 0 likes Thymosin alpha-1 has a regulatory history in several jurisdictions and a real clinical literature, which puts it in a different evidential category from most of its…
Packaging that arrived damaged: documenting it properly — a second dataset Replied, post #23 · Sourcing › Logistics · 17 Jan 2026 · 8 likes Post #22 is the version of this I will quote in future. One addition. Import restrictions by jurisdiction: what is legal to import for personal use varies enormously by…
Revisiting: Language barriers in accessing a prescription abroad Replied, post #57 · Access › International · 15 Jan 2026 · 1 like I read post #53 twice before replying, because I had assumed the opposite. Adding the boring version of Language barriers in accessing, because the interesting version…
Why the titration planner refuses to produce a schedule below a floor Replied, post #27 · Data & Tools › Calculators · 11 Jan 2026 · 4 likes Confirming post #24 from a second method, which matters more than confirming it from a second person. I disagree with the framing of titration planner refuses above,…
Comparing my trajectory with the trial curves, carefully Replied, post #87 · Outcomes › Progress reports · 8 Dec 2025 · 5 likes The best progress reports here read as records rather than as arguments, and that difference is visible within a sentence.
DXA precision and the least significant change for lean mass Replied, post #33 · Outcomes › Body composition · 1 Dec 2025 · 4 likes Comparing a body composition result against a population reference is a different exercise from tracking your own change, and the second is what most people want. That…
Substitution between formats during a shortage Replied, post #102 · Access › Shortages · 24 Nov 2025 · 7 likes Compounding during shortages: some jurisdictions allow pharmacy compounding when a marketed product is in shortage. That permission is jurisdiction-specific and…
[2026 update] How much of the diluent volume the powder itself displaces Replied, post #37 · Practice › Reconstitution · 24 Nov 2025 · 10 likes Preservative effectiveness is tested against a defined microbial challenge under defined conditions. It is not a licence to treat an entered vial as sterile…
The anatomy of a question that gets answered within an hour — the long version Replied, post #83 · Start Here › How to Ask · 11 Nov 2025 · 4 likes Worth separating two things that post #79 runs together. Nobody minds being asked to explain a term. The people who use them most are the quickest to define them, and a…
Older adults, sarcopenia risk, and the trade-off nobody quantifies Replied, post #27 · Clinical › Special populations · 7 Nov 2025 · 1 like Post #23 and I disagree about the size of the effect, not about the direction. Dedicated trials in under-studied populations are the only real remedy and several are…
The anatomy of a question that gets answered within an hour — the long version Replied, post #62 · Start Here › How to Ask · 5 Nov 2025 · 0 likes Confirming post #61 from a second method, which matters more than confirming it from a second person. Avoid "any advice?" at the end. It is so generic that people do…
Sleep tracking data and its considerable limitations Replied, post #76 · Wellbeing › Sleep · 24 Oct 2025 · 4 likes Sleep quality changes reported here have several plausible contributors, and separating drug effects from weight change, from schedule change, and from anxiety is…
What happens after your first post: likes, trust levels, and why none of it matters much… Replied, post #59 · Start Here › Welcome · 18 Oct 2025 · 0 likes Reading the guidelines before you post is genuinely worth the twenty minutes. Not because you will break one, but because the rules explain why the place reads the way…
The most useful thing you learned here that was not the answer you came for — a second… Replied, post #74 · Lounge › Off topic · 4 Oct 2025 · 0 likes The Lounge is also where to say the obvious thing you have been holding back in case it was too obvious. It usually is not, and two other people were holding it back as…
Coming back to: Resolution and tailing factor: real acceptance criteria Replied, post #92 · Analytics › HPLC & UHPLC · 2 Oct 2025 · 0 likes Careful with the language on Resolution and tailing factor. "Not detected" and "not present" are different findings and the first is a statement about the method.
High-resolution MS on aggregates and what it can see Replied, post #81 · Analytics › Mass spectrometry · 30 Sep 2025 · 5 likes Confirming post #80 from a second method, which matters more than confirming it from a second person. On high-resolution I would separate what is worth knowing from…
Compounds this community declines to help with, and why Replied, post #27 · Compounds › Other compounds · 28 Sep 2025 · 3 likes Where I part company with post #23, and it is a narrow parting. Melanocortin agonists: mechanism involves the melanocortin-4 receptor pathway that regulates appetite.…
Aggregated purity results across four services, with caveats — a second dataset Replied, post #112 · Data & Tools › Datasets · 10 Sep 2025 · 11 likes The arithmetic in post #111 is right; the assumption feeding it is the part to check. Aggregated purity results across four was covered in the wiki last year and the…
Specification in the result column: why that is a meaningful error Replied, post #41 · Analytics › COA interpretation · 7 Sep 2025 · 15 likes Post #39 is right about the mechanism and I think understates the practical bit. A chromatogram supplied as a small image is legible for peak shape and not for baseline…
Enforcement priorities versus written rules — does this still hold? Replied, post #25 · Sourcing › Regulatory · 23 Aug 2025 · 7 likes Adding the measurement that post #22 says would settle it. Anything written here about regulatory status should be assumed stale after twelve months, which is why the…
Second pass at: Journal club: STEP 4 and what a withdrawal design can prove Replied, post #56 · Evidence › Journal club · 23 Aug 2025 · 0 likes Post #52 and I disagree about the size of the effect, not about the direction. Critical appraisal template: (1) What did the trial set out to estimate? (2) Could the…
How the vendor documentation pages are maintained, and by whom — what changed since Replied, post #21 · Sourcing › Vendor reports · 5 Jul 2025 · 4 likes Marking my place. If it changes for me I will come back and say so.
Repeatability versus intermediate precision Replied, post #50 · Analytics › Method validation · 24 Jun 2025 · 1 like The arithmetic in post #49 is right; the assumption feeding it is the part to check. I changed my mind about repeatability versus intermediate precision after someone…
The CagriSema phase 2 paper and what a fixed combination buys — the long version Replied, post #141 · Compounds › Cagrilintide & amylin analogues · 19 Jun 2025 · 0 likes Checked the CagriSema phase 2 paper claim against the primary source this morning. It survives, with a narrower scope than the version quoted here. Posting the narrower…
Coming back to: Getting a referral rather than a refusal Replied, post #74 · Clinical › Prescriber conversations · 15 Jun 2025 · 0 likes Adding the measurement that post #71 says would settle it. Bringing a published document rather than a summary changes the conversation. Bringing a forum thread does not.
The CagriSema phase 2 paper and what a fixed combination buys — the long version Replied, post #65 · Compounds › Cagrilintide & amylin analogues · 11 Jun 2025 · 1 like Coming back to post #61, because the follow-up matters more than the original answer. What I would tell a new member reading about CagriSema phase 2 paper for the first…
Coming back to: Sample size calculations, read backwards from the published number Replied, post #32 · Evidence › Trials · 29 May 2025 · 12 likes If someone has run Sample size calculations properly I would rather read that than my own reconstruction of it. Posting mine only because the thread has gone quiet.
A ten-fold dose error caught before injection Replied, post #37 · Devices › Syringes & needles · 21 May 2025 · 0 likes Ten-fold dose error caught is well covered in the tag pages, and the older discussions are better than the recent ones because they were argued out properly. Worth…
Coverage for the indication versus for the drug Replied, post #70 · Access › Insurance & coverage · 18 May 2025 · 0 likes I disagree with the framing of coverage above, and I think it is a substantive disagreement rather than a terminological one. Setting out why, so it can be checked. The…
An orphaned page with no inbound links Replied, post #36 · Meta › Wiki maintenance · 4 May 2025 · 28 likes Second-hand on orphaned page, so weight it accordingly — someone whose method I trust told me this and I have not verified it myself.
Second pass at: Retatrutide mass and identity: what a report should show Replied, post #30 · Compounds › Retatrutide · 27 Apr 2025 · 0 likes Post #27 is right about the mechanism and I think understates the practical bit. Why this subcategory is more cautious than elsewhere: retatrutide is investigational,…
Certificates issued by the seller versus by a laboratory Replied, post #46 · Analytics › COA interpretation · 15 Apr 2025 · 4 likes Certificates from a supplier's own laboratory are not independent by definition. That is not an accusation, it is a description, and it is why independent submission…
Second pass at: Triple agonism: additive, synergistic, or neither? Replied, post #33 · Compounds › Retatrutide · 4 Apr 2025 · 5 likes Triple agonism at GLP-1, GIP and glucagon receptors is the defining feature and the glucagon limb is the one people find counter-intuitive. It raises energy expenditure…
Second pass at: A history of disordered eating: proceeding carefully Replied, post #18 · Wellbeing › Mental health · 14 Mar 2025 · 2 likes Building on post #15 rather than restating it. Nobody has said the unglamorous part of history of disordered eating yet, so: most of the variation is explained by…
Second pass at: Certificates issued by the seller versus by a laboratory Replied, post #89 · Analytics › COA interpretation · 31 Jan 2025 · 3 likes Post #86 and I disagree about the size of the effect, not about the direction. An itemised related-substances table with retention times says considerably more about…
Oxidation and deamidation mass shifts, tabulated Replied, post #38 · Analytics › Mass spectrometry · 18 Jan 2025 · 19 likes Adding a data point of agreement rather than a data point.
Oral semaglutide bioavailability and its variability between people — a second dataset Replied, post #45 · Compounds › Oral incretins · 26 Dec 2024 · 9 likes Orforglipron is a small molecule rather than a peptide, which changes almost everything about how it is made, stored and analysed. Comparing it to oral semaglutide as…
Molecular mass of semaglutide and why the figure differs between sources — does this… Replied, post #89 · Compounds › Semaglutide · 24 Dec 2024 · 0 likes The C-cell question: semaglutide triggered medullary thyroid carcinoma in rodent toxicology studies. A signal in rodents does not automatically appear in humans, but it…
Why mass spectrometry cannot tell you about an epimer Replied, post #6 · Analytics › Mass spectrometry · 18 Dec 2024 · 20 likes Quantitation by MS: most quantitation is done by LC-UV detection at 214 nm, not by MS, because extinction coefficients are better known. MS can quantify if an internal…
[2026 update] How to read a forest plot, properly, from scratch Replied, post #38 · Evidence › Trials · 16 Dec 2024 · 3 likes Picking up post #35: that is the part I would want checked first. Absolute and relative effects answer different questions. Write down the event rate in each arm and…
Why "any advice?" is the least effective ending for a post Replied, post #50 · Start Here › How to Ask · 19 Nov 2024 · 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…
Second pass at: Hoarding and why it makes a shortage worse Replied, post #131 · Access › Shortages · 14 Oct 2024 · 12 likes Post #128 put the caveat in the right place and I want to underline it. Anyone reporting availability should say the region and the date, because both determine whether…
Requesting a page: what makes a good request — what changed since Replied, post #82 · Documentation › Wiki requests · 12 Oct 2024 · 0 likes The number people quote for Requesting a page is a central estimate presented without its interval, and the interval is wide enough that the estimate is nearly…
Second pass at: Food noise reducing and the disorientation that can follow Replied, post #22 · Wellbeing › Mental health · 8 Oct 2024 · 0 likes Motivation and expectation: starting with clear motivation and realistic expectations about what will happen and when helps with psychological adjustment. For what it…
Amylin analogue mechanism: satiety signalling separate from GLP-1 Replied, post #3 · Compounds › Cagrilintide & amylin analogues · 19 Sep 2024 · 0 likes The opening post put the caveat in the right place and I want to underline it. The monoisotopic mass sits near 3749.9 Da, and the same caveat applies as everywhere…
Journal club: FLOW and the renal composite, component by component Replied, post #81 · Evidence › Journal club · 17 Jul 2024 · 3 likes Reading order that works for these sessions: registry entry, methods, baseline table, primary result, then abstract last. Reading the abstract first anchors everything…
Coming back to: Pricing far outside the range, in either direction Started this topic · Sourcing › Red flags · 16 Jul 2024 · 8 likes Pricing far outside the range, in either direction Writing it up because I had to work it out twice and would rather nobody else did. Pricing far outside the range — I…
Coming back to: Preparing for an appointment: one page, three questions Replied, post #14 · Clinical › Prescriber conversations · 2 Jul 2024 · 24 likes Prescription logistics: confirm whether it will be filled locally, requires mail order, or will be prescribed off-label and needs a compounding pharmacy. Different…
How this community labels and discusses unrefereed work Replied, post #25 · Evidence › Preprints · 18 Jun 2024 · 13 likes Picking up post #22: that is the part I would want checked first. Author track record is a weak signal and it is a signal. A group that has published carefully for…