m.perrin

TL2 Moderator · 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. Cost and turnaround: different services have different pricing and turnaround…
Follow-up: How compounding permissions changed when supply normalised Replied, post #63 · Sourcing › Regulatory · 24 Jul 2026 · 0 likes Coming back to post #61, because the follow-up matters more than the original answer. Practical note that does not fit anywhere else. Whatever you conclude from this…
Semaglutide and gastric emptying — the mechanism behind most of the side-effect profile Replied, post #112 · Compounds › Semaglutide · 19 Jul 2026 · 7 likes I read post #110 twice before replying, because I had assumed the opposite. The C-cell question: semaglutide triggered medullary thyroid carcinoma in rodent toxicology…
Journal club: SUSTAIN 6 and its retinopathy signal Replied, post #46 · Evidence › Journal club · 10 Jul 2026 · 6 likes I read post #44 twice before replying, because I had assumed the opposite. STEP 1 (N Engl J Med 2021): The pivotal obesity trial for semaglutide and the reference point…
[2026 update] Antibiotics and a course of something with delayed emptying Replied, post #21 · Practice › Interactions · 7 Jul 2026 · 4 likes Insulin interaction: semaglutide and tirzepatide are not contraindicated with insulin but the combination carries hypoglycemia risk if insulin doses are not adjusted.…
Follow-up: Sleep quality changes during weight loss Replied, post #59 · Wellbeing › Sleep · 2 Jul 2026 · 9 likes Worth separating two things that post #55 runs together. Appetite suppression and nighttime eating: if nighttime eating was a pattern, appetite suppression changes that…
Sleep quality changes during weight loss Replied, post #5 · Wellbeing › Sleep · 29 Jun 2026 · 0 likes Energy and sleep needs: rapid weight loss increases real metabolic stress. Sleep needs might increase even though appetite for food has decreased. Prioritising sleep is…
Does a peptide degrade silently, with no visual change? Replied, post #57 · Practice › Storage & stability · 27 Jun 2026 · 17 likes Container choice matters: the material of the vial, the rubber closure, the fill volume all affect how quickly the contents degrade. Smaller fill volumes lose less to…
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 On post #4 — agreed on the reasoning, with one qualification. Humour: light, relevant humour is welcome. Cruel humour targeting individuals or groups is not.
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 The specific question in the title is more useful than you might think. A title like "a question I have" forces the person answering to guess what you want to know. A…
Follow-up: Search filters: what is missing Replied, post #123 · Meta › Site feedback · 8 Jun 2026 · 6 likes Coming back to post #121, because the follow-up matters more than the original answer. Navigation problems: if you cannot find something you expected to exist, or the…
Second pass at: Sleep apnoea improving and the equipment implications Replied, post #49 · Wellbeing › Sleep · 2 Jun 2026 · 0 likes Gastrointestinal effects overnight: nausea or reflux or constipation at night can disrupt sleep. Dosing timing (morning versus evening) might help if nighttime GI…
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 What "verified" means on our pages: specific lots were independently measured on stated dates by named services and results were consistent with the supplier's…
Receptor desensitisation as a tolerance hypothesis, and its weak evidence Replied, post #5 · Pharmacology › Receptor biology · 27 May 2026 · 4 likes Coming back to post #3, because the follow-up matters more than the original answer. GLP-1 receptor signalling: the GLP-1 receptor is expressed on beta cells (insulin…
[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 A 10 mg vial reconstituted three different ways: 1 mL diluent gives 10 mg/mL, 2 mL gives 5 mg/mL, 4 mL gives roughly 2.5 mg/mL. The arithmetic is the same; the…
A supplier who responds to a discrepancy with silence — what changed since Replied, post #31 · Sourcing › Red flags · 15 Apr 2026 · 17 likes Documentation quality as a signal: a supplier that reports method identifiers, distinguishes specification from result, and states the counter-ion form is telling you…
[2026 update] What a purity-only report leaves out Replied, post #83 · Sourcing › Independent verification · 8 Apr 2026 · 2 likes Cost and turnaround: different services have different pricing and turnaround times. Janoshik's turnaround is weeks by mail; VendorInvestigate documentation review is…
The 2.5 mg starting dose is not a therapeutic dose — why that matters Replied, post #66 · Compounds › Tirzepatide · 1 Apr 2026 · 0 likes SURMOUNT-OSA is notable because it used an objective physiological endpoint, the apnoea-hypopnoea index, rather than a symptom scale. Two parallel trials, with and…
Measurement error in home scales, with a worked standard deviation — the long version Replied, post #67 · Research Methods › Statistics · 1 Apr 2026 · 12 likes This follows post #64 rather than contradicting it. Confounding: a third variable explains an apparent association. In randomised data, randomisation balances…
Constipation management, with a dietitian's contribution Replied, post #43 · Practice › Side effects · 22 Mar 2026 · 25 likes This follows post #40 rather than contradicting it. Injection site reaction: local erythema, nodules, or induration at injection sites is reported by some people. Site…
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 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…
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 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…
Coming back to: Training through a dose escalation week Replied, post #49 · Nutrition & Training › Resistance training · 11 Mar 2026 · 0 likes Frequency: three sessions per week of full-body training is easier to maintain than higher frequencies on an energy deficit. Consistency beats intensity when recovery…
[2026 update] Regional warehouse stock versus direct despatch Replied, post #15 · Sourcing › Logistics · 11 Mar 2026 · 17 likes Declaring contents accurately: declaring accurately reduces intervention risk. A declaration of "peptide research chemical, 5 grams" is better than "vitamin" or "other"…
Second pass at: Metformin co-administration and additive GI effects Replied, post #63 · Practice › Interactions · 9 Mar 2026 · 4 likes This follows post #60 rather than contradicting it. I disagree with the reply above, and I think the disagreement is substantive rather than terminological. The…
Contributing data without breaching anyone's privacy Replied, post #22 · Data & Tools › Datasets · 3 Mar 2026 · 2 likes Community-collected datasets: some members have compiled datasets from their own experience and shared them. They are self-reported, unblinded, and therefore limited as…
Why "dose equivalence" between different incretin analogues is a weak concept Replied, post #51 · Practice › Dosing & titration · 17 Feb 2026 · 16 likes Stepping down deliberately: the withdrawal trials show that stopping is followed by regain. The step-down literature is thinner. The conservative assumption is that…
Second pass at: What to keep a record of at the point of payment Replied, post #8 · Sourcing › Payments · 6 Feb 2026 · 6 likes post #7 answers the question as asked. The question underneath it is different. For anyone arriving from a search: the marked solution above is the direct answer, and…
Half-life, steady state, and accumulation worked through — a second dataset Replied, post #70 · Pharmacology › Pharmacokinetics · 28 Jan 2026 · 6 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…
Coming back to: The SOUL trial and oral semaglutide cardiovascular outcomes Replied, post #90 · Compounds › Oral incretins · 22 Jan 2026 · 10 likes Trial adherence in an oral trial with strict administration requirements is genuinely worse than trial-published data often suggests. That is why the exposure…
A partial dose because the pen emptied mid-injection Replied, post #79 · Practice › Administration · 9 Jan 2026 · 30 likes A genuinely late dose: the labelling generally says that if the next dose is more than a couple of days away, take it as soon as you notice. If the next dose is close,…
"Greater than or equal to 99%" as a specification rather than a result Replied, post #103 · Analytics › COA interpretation · 3 Jan 2026 · 0 likes Counter-ion form is crucial: peptides are isolated as salts, most often trifluoroacetate from reversed-phase purification or acetate after salt exchange. 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 I read post #22 twice before replying, because I had assumed the opposite. Lean mass loss: the rate of lean tissue loss depends on protein intake, resistance training…
Coming back to: Over-dilution: when your dose falls below one readable graduation Replied, post #98 · Practice › Reconstitution · 21 Dec 2025 · 1 like How much of the diluent volume the powder itself displaces: for a small peptide vial, the powder volume is negligible. For a larger vial or a kit with multiple…
Pen mechanics when the cartridge is nearly empty — does this still hold? Replied, post #30 · Devices › Pens & autoinjectors · 16 Dec 2025 · 26 likes On post #26 — agreed on the reasoning, with one qualification. Pen mechanics: most pens are dial-and-inject devices where you dial the dose on the pen and push the…
MHRA statements, read directly Replied, post #46 · Regional › UK & Ireland · 10 Dec 2025 · 7 likes Compounding pharmacies: UK allows compounding under specific conditions when a licensed product is unavailable. That is not a front-line option but becomes relevant…
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 What you have already read matters. Saying "I read the maintained page on this and I still have a gap" tells people they do not need to point you at the same resource…
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. Pharmacy acquisition cost: a pharmacy pays less than the patient pays, even at insurance rates. That…
Warfarin and altered intake: the monitoring argument — the long version Replied, post #40 · Practice › Interactions · 29 Oct 2025 · 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…
Documentation that appears only after payment Replied, post #61 · Sourcing › Red flags · 28 Oct 2025 · 0 likes Pricing patterns: unusually low prices for what are otherwise consistent with market rates might indicate lower quality, stolen goods, or a scam. Unusually high prices…
Semaglutide versus liraglutide head to head: reading STEP 8 carefully Replied, post #77 · Compounds › Semaglutide · 18 Oct 2025 · 16 likes Worth separating two things that post #73 runs together. The C-cell question: semaglutide triggered medullary thyroid carcinoma in rodent toxicology studies. A signal…
The nausea timeline across the first four weeks, with a tabulated log Replied, post #119 · Practice › Side effects · 4 Oct 2025 · 15 likes Worth separating two things that post #115 runs together. Practical note that does not fit anywhere else. Whatever you conclude from this topic, write down what you did…
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. Two things before anyone answers the substance. First, the context in the first post is clear and…
Revisiting: German, French and Dutch differences, compared Replied, post #76 · Regional › European Union · 22 Sep 2025 · 5 likes Netherlands: CBG-MEB implements framework. GPs are first point of contact. Insurance coverage for weight management is conditional on structured lifestyle programme…
What a purity-only report leaves out Replied, post #19 · Sourcing › Independent verification · 19 Sep 2025 · 7 likes When results are inconclusive: if a testing service reports "insufficient to verify" on a documentation review, that is not a negative finding about the product. It…
The nausea timeline across the first four weeks, with a tabulated log Replied, post #73 · Practice › Side effects · 18 Sep 2025 · 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…
Hepatic impairment and the absence of data Replied, post #10 · Clinical › Special populations · 10 Aug 2025 · 0 likes Picking up post #7: that is the part I would want checked first. Disordered eating history: a history of anorexia nervosa, bulimia, or other eating disorders changes…
A request that was declined, and the reasoning — a second dataset Replied, post #43 · Documentation › Wiki requests · 10 Aug 2025 · 0 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…
How to read a forest plot, properly, from scratch Replied, post #12 · Evidence › Trials · 5 Aug 2025 · 13 likes Open-label design: unblinded trials admit expectation effects. For weight-loss trials where one arm loses substantial weight and the other does not, complete blinding…
Second pass at: Triple agonism: additive, synergistic, or neither? Replied, post #88 · Compounds › Retatrutide · 1 Aug 2025 · 14 likes Coming back to post #86, because the follow-up matters more than the original answer. Mass and identity: a report on retatrutide should state the mass detected by…
Coming back to: An 18-month record including the parts that went badly Replied, post #77 · Outcomes › Progress reports · 8 Jul 2025 · 0 likes Coming back to post #75, because the follow-up matters more than the original answer. Exercise volume changes: increasing exercise intensity or duration can mask weight…
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 Picking up post #89: that is the part I would want checked first. Thank you for the correction. I have edited my earlier post with a note rather than silently, so the…
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 Fluid intake: baseline needs increase with gastrointestinal effects and exercise. Thirst is not a reliable guide during appetite suppression. Drinking regularly (not…
Domestic fridge temperature mapping: a cheap experiment — what changed since Replied, post #97 · Devices › Cold chain · 4 May 2025 · 14 likes Reconstituted solutions: once reconstituted, solutions are less stable than lyophilised powder. Refrigerate prepared solutions immediately after preparation. Most…
Retatrutide phase 2 in type 2 diabetes: the Lancet paper Replied, post #5 · Compounds › Retatrutide · 3 May 2025 · 0 likes The phase 2 obesity paper reported dose-dependent weight reduction of a magnitude that attracted attention. It also reported dose-dependent heart-rate increases. The…
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. Retatrutide is investigational. Anything obtained outside a trial is by definition research-use-only material…
Pharmaceutical compounding rules, summarised from primary sources Replied, post #53 · Sourcing › Regulatory · 1 Mar 2025 · 0 likes Labelling and intended use: a compound sold as "research-use-only" does not change its pharmacology if ingested. It changes the legal status of the sale. The labelling…
Consistent declarations and why they matter more than clever ones Replied, post #87 · Sourcing › Logistics · 25 Feb 2025 · 3 likes Reshipment after seizure: if a parcel is seized, some suppliers will reship; others will not. That is a supplier choice and should be understood before ordering in a…
Anxiety in the first weeks: drug, situation, or both Replied, post #46 · Wellbeing › Mental health · 4 Feb 2025 · 1 like I read post #44 twice before replying, because I had assumed the opposite. When to involve a professional: if mood changes are persistent, deepen over weeks, or…
Why mass spectrometry cannot tell you about an epimer Replied, post #43 · Analytics › Mass spectrometry · 31 Jan 2025 · 0 likes Desalting before analysis: some samples need desalting to remove salts that suppress the peptide signal. Report whether desalting was used, because it can affect the…
Second pass at: Certificates issued by the seller versus by a laboratory Replied, post #12 · Analytics › COA interpretation · 16 Jan 2025 · 17 likes I read post #10 twice before replying, because I had assumed the opposite. When a document puts the specification in the result column, it has told you the release…
Recovery when intake is low: what to cut first Replied, post #84 · Nutrition & Training › Resistance training · 14 Jan 2025 · 2 likes post #83 answers the question as asked. The question underneath it is different. Frequency: three sessions per week of full-body training is easier to maintain than…
Reading a supplementary appendix and finding the interesting part Replied, post #63 · Evidence › Trials · 9 Jan 2025 · 10 likes Generalisability: the enrolled population was selected in ways that matter. Entry criteria, run-in periods, and the simple fact that people who agree to a multi-year…
How compounding permissions changed when supply normalised Replied, post #5 · marked as the solution · Sourcing › Regulatory · 2 Jan 2025 · 7 likes Picking up post #2: that is the part I would want checked first. Labelling and intended use: a compound sold as "research-use-only" does not change its pharmacology if…
Oxidation pathways for methionine and tryptophan Replied, post #23 · Analytics › Impurities & related substances · 27 Dec 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.
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 post #31 answers the question as asked. The question underneath it is different. Linearity: the detector response is proportional to compound concentration across the…
Revisiting: Melanocortin agonists: mechanism and the documented adverse profile Replied, post #42 · Compounds › Other compounds · 10 Oct 2024 · 20 likes On post #38 — agreed on the reasoning, with one qualification. Two things before anyone answers the substance. First, the context in the first post is clear and…
The topic list is dense — is that deliberate? Replied, post #33 · Meta › Site feedback · 2 Oct 2024 · 31 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…
Journal club: SURPASS-2 and the semaglutide 1 mg comparator Replied, post #60 · Evidence › Journal club · 1 Oct 2024 · 21 likes post #59 answers the question as asked. The question underneath it is different. Thank you for the correction. I have edited my earlier post with a note rather than…
Coming back to: Preparing for an appointment: one page, three questions Replied, post #67 · Clinical › Prescriber conversations · 29 Sep 2024 · 0 likes post #66 answers the question as asked. The question underneath it is different. What to bring: copies of relevant lab results, pharmacy records (to confirm doses…
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 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…
Where the four-week escalation interval comes from, and what it is not Replied, post #38 · Practice › Dosing & titration · 3 Jul 2024 · 0 likes How the published trials escalated: they used specific step sizes and intervals. The STEP programme used a particular cadence; the SURPASS and SURMOUNT programmes used…
Assessing a warm arrival: the decision process — one year on Replied, post #98 · Sourcing › Logistics · 1 Jun 2024 · 21 likes Insurance and carrier liability: most parcel carriers limit liability. Understanding the limits before choosing a carrier matters if you are shipping expensive material.