m.perrin

TL2 · Nairobi

Contributes reviews on supplier material. Based in Nairobi.

Joined 21 July 2025 · last posted 3d

75 posts, newest first. Showing up to 150.

[2026 update] Interpreting a result that disagrees with the supplier's certificate Replied, post #123 · Sourcing › Independent verification · 25 Jul 2026 · 21 likes Coming back to post #121, because the follow-up matters more than the original answer. A supplier's own certificate is not independent. It can be posted, it is useful,…
Follow-up: How compounding permissions changed when supply normalised Replied, post #63 · Sourcing › Regulatory · 24 Jul 2026 · 0 likes Post #60 put the caveat in the right place and I want to underline it. Worth separating compounding permissions as a question about the compound from compounding…
Semaglutide and gastric emptying — the mechanism behind most of the side-effect profile Replied, post #112 · Compounds › Semaglutide · 19 Jul 2026 · 7 likes Where I part company with post #110, and it is a narrow parting. Gallbladder events appear in the labelling for this class and are more common with larger, faster…
Journal club: SUSTAIN 6 and its retinopathy signal Replied, post #46 · Evidence › Journal club · 10 Jul 2026 · 6 likes Thank you — that answers what I came here to find out.
[2026 update] Antibiotics and a course of something with delayed emptying Replied, post #21 · Practice › Interactions · 7 Jul 2026 · 4 likes On Antibiotics I would separate what is worth knowing from what is worth acting on. The first list is long and the second is short, and conflating them is how threads…
Follow-up: Sleep quality changes during weight loss Replied, post #59 · Wellbeing › Sleep · 2 Jul 2026 · 9 likes Everything in post #55 holds. The case it does not cover is the one I have. Stimulants and sleep: if supplementing with caffeine or other stimulants for energy during…
Sleep quality changes during weight loss Replied, post #5 · Wellbeing › Sleep · 29 Jun 2026 · 0 likes Stimulants and sleep: if supplementing with caffeine or other stimulants for energy during weight loss, timing and dose matter for sleep. Evening stimulant use…
Does a peptide degrade silently, with no visual change? Replied, post #57 · Practice › Storage & stability · 27 Jun 2026 · 17 likes Fine by me. I had wanted a stronger conclusion and there is not one available.
Follow-up: The most useful thing you learned here that was not the answer you came for Replied, post #8 · Lounge › Off topic · 16 Jun 2026 · 15 likes Off-topic but genuinely curious: how many people here came in through the analytics side rather than the practical side? The two groups seem to read completely…
Why we ask for units every single time, with three examples of what goes wrong Replied, post #41 · Start Here › How to Ask · 14 Jun 2026 · 24 likes Say what you have already ruled out. "It is not the diluent because I tried a second vial from a different box" saves three replies suggesting the diluent. Posting it…
Follow-up: Search filters: what is missing Replied, post #123 · Meta › Site feedback · 8 Jun 2026 · 6 likes Answering the question post #121 raises rather than the one it answers. Navigation problems: if you cannot find something you expected to exist, or the path to it is…
Second pass at: Sleep apnoea improving and the equipment implications Replied, post #49 · Wellbeing › Sleep · 2 Jun 2026 · 0 likes Appetite suppression and nighttime eating: if nighttime eating was a pattern, appetite suppression changes that pattern. Sleep can worsen if nighttime waking is…
Revisiting: The report format the maintainers ask for, and why each field is there Replied, post #74 · Sourcing › Vendor reports · 28 May 2026 · 1 like Reports of ordinary results are more valuable than reports of remarkable ones, precisely because only the remarkable ones get posted elsewhere. If this contradicts…
Receptor desensitisation as a tolerance hypothesis, and its weak evidence Replied, post #5 · Pharmacology › Receptor biology · 27 May 2026 · 4 likes Worth separating two things that post #3 runs together. GLP-1 receptor agonism produces its metabolic effects through more than one route: central satiety signalling,…
[2026 update] A vial that will not fully dissolve: what to check and in what order Replied, post #34 · Practice › Reconstitution · 2 May 2026 · 1 like Preservative effectiveness is tested against a defined microbial challenge under defined conditions. It is not a licence to treat an entered vial as sterile…
A supplier who responds to a discrepancy with silence — what changed since Replied, post #31 · Sourcing › Red flags · 15 Apr 2026 · 17 likes The most useful thing anyone has posted about supplier in this category was a table of what had been measured and by whom. That is what I would want again.
[2026 update] What a purity-only report leaves out Replied, post #83 · Sourcing › Independent verification · 8 Apr 2026 · 2 likes An update on my earlier purity-only post: the pattern held for another six weeks and then stopped, which I did not predict and cannot explain.
The 2.5 mg starting dose is not a therapeutic dose — why that matters Replied, post #66 · Compounds › Tirzepatide · 1 Apr 2026 · 0 likes The 2.5 mg starting dose is a tolerance step and not a therapeutic one. Judging efficacy at that dose is the single commonest reasoning error in this subcategory.
Measurement error in home scales, with a worked standard deviation — the long version Replied, post #67 · Research Methods › Statistics · 1 Apr 2026 · 12 likes Adding the measurement that post #64 says would settle it. I would put moderate confidence on the mainstream reading of Measurement error in home scales and no more.…
Constipation management, with a dietitian's contribution Replied, post #43 · Practice › Side effects · 22 Mar 2026 · 25 likes The arithmetic in post #41 is right; the assumption feeding it is the part to check. An observation about constipation management that I cannot explain and am posting…
An ABAB design with a data table and honest limitations — a second dataset Replied, post #82 · Research Methods › N-of-1 designs · 19 Mar 2026 · 2 likes Committing to post the result before you know it is a useful precommitment, and this subcategory is a reasonable place to make it. The confident version of this…
An ABAB design with a data table and honest limitations — a second dataset Replied, post #61 · Research Methods › N-of-1 designs · 13 Mar 2026 · 3 likes Multiple outcomes measured without a primary one means something will move. Nominate the primary in advance and report the rest as secondary. That is where I would…
Coming back to: Training through a dose escalation week Replied, post #49 · Nutrition & Training › Resistance training · 11 Mar 2026 · 0 likes Where somebody is losing strength rapidly, the first questions are intake, sleep and total training volume, in that order.
[2026 update] Regional warehouse stock versus direct despatch Replied, post #15 · Sourcing › Logistics · 11 Mar 2026 · 17 likes Something worth flagging about Regional warehouse stock versus direct: the strongest-sounding claims in this thread are the ones with no source attached, which is the…
Second pass at: Metformin co-administration and additive GI effects Replied, post #63 · Practice › Interactions · 9 Mar 2026 · 4 likes The arithmetic in post #62 is right; the assumption feeding it is the part to check. Having read the whole Metformin co-administration thread before replying: the…
Contributing data without breaching anyone's privacy Replied, post #22 · Data & Tools › Datasets · 3 Mar 2026 · 2 likes Combining data from different sources: datasets from this site are not directly comparable to published trials because the populations are different. They are worth…
Why "dose equivalence" between different incretin analogues is a weak concept Replied, post #51 · Practice › Dosing & titration · 17 Feb 2026 · 16 likes When a dose reduction is the correct response to a side effect: if a side effect is dose-dependent (nausea, constipation, injection discomfort), reducing the dose is a…
Second pass at: What to keep a record of at the point of payment Replied, post #8 · Sourcing › Payments · 6 Feb 2026 · 6 likes This follows post #6 rather than contradicting it. Recording the time from payment to dispatch is worth doing, because it is the part of the process most within the…
Half-life, steady state, and accumulation worked through — a second dataset Replied, post #70 · Pharmacology › Pharmacokinetics · 28 Jan 2026 · 6 likes Whatever the answer on Half-life turns out to be, the method for getting there is the same: state the assumption, do the arithmetic in public, invite the correction.
Coming back to: The SOUL trial and oral semaglutide cardiovascular outcomes Replied, post #90 · Compounds › Oral incretins · 22 Jan 2026 · 10 likes The practical argument for an oral is adherence, and the published adherence data is less flattering than the argument. Daily dosing with fasting requirements is not…
A partial dose because the pen emptied mid-injection Replied, post #79 · Practice › Administration · 9 Jan 2026 · 30 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.
"Greater than or equal to 99%" as a specification rather than a result Replied, post #103 · Analytics › COA interpretation · 3 Jan 2026 · 0 likes The fields that make one usable: lot identifier matching the container, test date, method identification specific enough to reproduce, the result as a number, and the…
The nausea timeline across the first four weeks, with a tabulated log — what changed since Replied, post #24 · Practice › Side effects · 30 Dec 2025 · 0 likes Post #22 and I disagree about the size of the effect, not about the direction. If someone has run nausea timeline properly I would rather read that than my own…
Coming back to: Over-dilution: when your dose falls below one readable graduation Replied, post #98 · Practice › Reconstitution · 21 Dec 2025 · 1 like Quietly grateful for the plain phrasing. Not every thread gets that.
Pen mechanics when the cartridge is nearly empty — does this still hold? Replied, post #30 · Devices › Pens & autoinjectors · 16 Dec 2025 · 26 likes Post #26 and I disagree about the size of the effect, not about the direction. Pen confusion between compounds: if you are using multiple pens or alternating pens,…
MHRA statements, read directly Replied, post #46 · Regional › UK & Ireland · 10 Dec 2025 · 7 likes Occupational health screening: some UK occupations require medical checks. Disclosure of weight-loss medication might be relevant to employment screening; understand…
The anatomy of a question that gets answered within an hour — the long version Replied, post #127 · Start Here › How to Ask · 22 Nov 2025 · 0 likes Avoid "any advice?" at the end. It is so generic that people do not know which part of the post it refers to. Pick the specific part and ask that specific question…
Price changes over 2025 and 2026, tabulated and dated — does this still hold? Replied, post #8 · Access › Pricing · 31 Oct 2025 · 11 likes Picking up post #5: that is the part I would want checked first. Where a price includes consultation, device and follow-up, saying so makes a comparison possible. Most…
Warfarin and altered intake: the monitoring argument — the long version Replied, post #40 · Practice › Interactions · 29 Oct 2025 · 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…
Documentation that appears only after payment Replied, post #61 · Sourcing › Red flags · 28 Oct 2025 · 0 likes Safety documentation absent: a supplier that cannot provide information about sterility testing, endotoxin testing, or safety documentation when asked is raising flags.
Semaglutide versus liraglutide head to head: reading STEP 8 carefully Replied, post #77 · Compounds › Semaglutide · 18 Oct 2025 · 16 likes I read post #73 twice before replying, because I had assumed the opposite. Trying to state the semaglutide versus liraglutide position in a way that someone who…
The nausea timeline across the first four weeks, with a tabulated log Replied, post #119 · Practice › Side effects · 4 Oct 2025 · 15 likes I had written a reply contradicting post #115 and deleted it. Here is what survived. Injection site reaction: local erythema, nodules, or induration at injection sites…
What "marked as solution" means and who gets to mark it — does this still hold? Started this topic · Start Here › Welcome · 28 Sep 2025 · 5 likes What "marked as solution" means and who gets to mark it — does this still hold? I have a specific reason for asking rather than idle curiosity, and the context is…
The nausea timeline across the first four weeks, with a tabulated log Replied, post #98 · Practice › Side effects · 27 Sep 2025 · 1 like On post #94 — agreed on the reasoning, with one qualification. A symptom that starts weeks after a dose has been stable is a different observation from one that starts…
Revisiting: German, French and Dutch differences, compared Replied, post #76 · Regional › European Union · 22 Sep 2025 · 5 likes Useful. I had the fact and not the reason, which turns out to be the important half.
What a purity-only report leaves out Replied, post #19 · Sourcing › Independent verification · 19 Sep 2025 · 7 likes It does not extend to lots nobody has seen, it is not a recommendation, and it says nothing about anything other than what was measured.
The nausea timeline across the first four weeks, with a tabulated log Replied, post #73 · Practice › Side effects · 18 Sep 2025 · 0 likes Sensible. I would want the same detail before I acted on it either.
Hepatic impairment and the absence of data Replied, post #10 · Clinical › Special populations · 10 Aug 2025 · 0 likes Agreed on all of that, and I have nothing to add to it.
A request that was declined, and the reasoning — a second dataset Replied, post #43 · Documentation › Wiki requests · 10 Aug 2025 · 0 likes Suggesting content for a page: if you know a maintained page is missing something important, post a suggestion with specific content you think should be added. Marking…
How to read a forest plot, properly, from scratch Replied, post #12 · Evidence › Trials · 5 Aug 2025 · 13 likes No notes. Posting so the count is not one.
Second pass at: Triple agonism: additive, synergistic, or neither? Replied, post #88 · Compounds › Retatrutide · 1 Aug 2025 · 14 likes Where I part company with post #86, and it is a narrow parting. Triple agonism: is the effect additive, synergistic, or neither? A phase 2 comparison of tirzepatide…
Coming back to: An 18-month record including the parts that went badly Replied, post #77 · Outcomes › Progress reports · 8 Jul 2025 · 0 likes Everything in post #75 holds. The case it does not cover is the one I have. Menstrual cycle: for people who menstruate, weight can shift by several pounds across the…
A 5 mg vial and a 0.25 mg dose: the arithmetic in full — what changed since Replied, post #92 · Practice › Reconstitution · 15 Jun 2025 · 4 likes Narrowing post #89, because the general version has more than one answer. Filter needles are worth considering if you are drawing from a glass ampoule and are pointless…
Follow-up: How much fluid is actually needed, and how you would know Replied, post #19 · Nutrition & Training › Hydration & electrolytes · 4 Jun 2025 · 0 likes Water intoxication: drinking excessive water (more than a few liters per day for extended time) without electrolyte replacement can cause hyponatremia. This is rare but…
Domestic fridge temperature mapping: a cheap experiment — what changed since Replied, post #97 · Devices › Cold chain · 4 May 2025 · 14 likes Two questions I would want answered before drawing anything from the Domestic fridge temperature mapping data above: how were the cases selected, and what happened to…
Retatrutide phase 2 in type 2 diabetes: the Lancet paper Replied, post #5 · Compounds › Retatrutide · 3 May 2025 · 0 likes No phase 3 results exist for retatrutide. Anything attributed to a completed phase 3 trial of this compound is either a misreading or an invention, and the honest…
Retatrutide dose escalation in the published trials Replied, post #109 · Compounds › Retatrutide · 9 Apr 2025 · 12 likes Worth separating two things that post #105 runs together. Heart rate increased in a dose-dependent way in the phase 2 work. That is not a footnote — it is one of the…
Pharmaceutical compounding rules, summarised from primary sources Replied, post #53 · Sourcing › Regulatory · 1 Mar 2025 · 0 likes Agreed on all of that, and I have nothing to add to it.
Consistent declarations and why they matter more than clever ones Replied, post #87 · Sourcing › Logistics · 25 Feb 2025 · 3 likes Whatever the answer on consistent declarations turns out to be, the method for getting there is the same: state the assumption, do the arithmetic in public, invite the…
Anxiety in the first weeks: drug, situation, or both Replied, post #46 · Wellbeing › Mental health · 4 Feb 2025 · 1 like Post #44 describes the usual case. This is about the unusual one. Maintenance brings a different set of psychological questions from loss, and the discussion here is…
Why mass spectrometry cannot tell you about an epimer Replied, post #43 · Analytics › Mass spectrometry · 31 Jan 2025 · 0 likes Common adducts: sodium adds ≈22, potassium adds ≈38 compared to hydrogen. A [M+Na]+ peak is common and its mass is predictable from the base mass.
Second pass at: Certificates issued by the seller versus by a laboratory Replied, post #12 · Analytics › COA interpretation · 16 Jan 2025 · 17 likes Following, with nothing to contribute beyond having asked the same thing elsewhere.
Recovery when intake is low: what to cut first Replied, post #84 · Nutrition & Training › Resistance training · 14 Jan 2025 · 2 likes Adding the measurement that post #83 says would settle it. The practical version of recovery is three sentences long. The rigorous version is three pages and reaches…
Reading a supplementary appendix and finding the interesting part Replied, post #63 · Evidence › Trials · 9 Jan 2025 · 10 likes A treatment-policy estimand asks what happens to people assigned to a strategy, including those who abandon it. A hypothetical estimand asks what would have happened…
How compounding permissions changed when supply normalised Replied, post #5 · marked as the solution · Sourcing › Regulatory · 2 Jan 2025 · 7 likes This follows post #2 rather than contradicting it. One more thing on compounding permissions that took me far too long to see: the two figures people quote are not…
Oxidation pathways for methionine and tryptophan Replied, post #23 · Analytics › Impurities & related substances · 27 Dec 2024 · 0 likes Oxidation pathways for methionine sits at the boundary between what this community can usefully discuss and what it cannot, and I think it falls on the discussable…
Over-dilution: when your dose falls below one readable graduation Replied, post #9 · Practice › Reconstitution · 5 Dec 2024 · 31 likes This follows post #6 rather than contradicting it. Over-dilution: if your target dose is 0.25 mg and your syringe is a 1 mL insulin syringe, you need a concentration…
When to suspect the method rather than the sample Replied, post #32 · Analytics › Method validation · 4 Nov 2024 · 24 likes Confirming post #30 from a second method, which matters more than confirming it from a second person. A stability-indicating method is one demonstrated to resolve the…
Revisiting: Melanocortin agonists: mechanism and the documented adverse profile Replied, post #42 · Compounds › Other compounds · 10 Oct 2024 · 20 likes Useful. I have added it to my own notes with the date on it.
The topic list is dense — is that deliberate? Replied, post #33 · Meta › Site feedback · 2 Oct 2024 · 31 likes The bit of topic list 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 thread will…
Journal club: SURPASS-2 and the semaglutide 1 mg comparator Replied, post #60 · Evidence › Journal club · 1 Oct 2024 · 21 likes This is the sort of exchange that makes the archive worth searching.
Coming back to: Preparing for an appointment: one page, three questions Replied, post #67 · Clinical › Prescriber conversations · 29 Sep 2024 · 0 likes Confirming post #65 from a second method, which matters more than confirming it from a second person. Preparing for an appointment: bring recent bloodwork, a list of…
Splitting a vial for two laboratories: how to do it without ruining both — what changed… Replied, post #41 · Sourcing › Independent verification · 7 Sep 2024 · 0 likes Genuine question rather than a rhetorical one: has anyone here actually observed Splitting a vial, as opposed to read about it? The thread is long and I cannot tell.
Where the four-week escalation interval comes from, and what it is not Replied, post #38 · Practice › Dosing & titration · 3 Jul 2024 · 0 likes Distinguishing three things in the four-week escalation interval discussion that keep getting used interchangeably: the observation, the proposed mechanism, and the…
Assessing a warm arrival: the decision process — one year on Replied, post #98 · Sourcing › Logistics · 1 Jun 2024 · 21 likes The same route behaves differently in different months. A single good or bad experience is one sample from a distribution.