a.hartmann

TL2 · Seville

Contributes reviews on supplier material. Based in Seville.

Joined 25 August 2025 · last posted 20h

88 posts, newest first. Showing up to 150.

Shakes versus food: a pragmatic assessment Replied, post #27 · Nutrition & Training › Protein & intake · 27 Jul 2026 · 26 likes Noted, and I have changed what I was going to do on the strength of it.
Reading order for a first week here, and what to skip until later — what changed since Replied, post #85 · Start Here › Welcome · 26 Jul 2026 · 21 likes The Lounge is a real category rather than a dumping ground. The sourcing rule still applies there, which surprises people, but the register is looser and nobody minds a…
How to ask about something you suspect is a bad idea — a second dataset Started this topic · Start Here › How to Ask · 15 Jul 2026 · 0 likes How to ask about something you suspect is a bad idea — a second dataset — that is the question, and I have not found it answered plainly anywhere I have looked.…
Coming back to: Delayed gastric emptying and oral medication absorption: which drugs… Replied, post #24 · Practice › Interactions · 14 Jul 2026 · 0 likes Building on post #21 rather than restating it. Vitamins: most vitamins have no significant interaction. Fat-soluble vitamins (A, D, E, K) might be affected by the…
What a certificate commits its issuer to — one year on Replied, post #103 · Analytics › COA interpretation · 5 Jul 2026 · 5 likes Everything in post #101 holds. The case it does not cover is the one I have. Peptide content and chromatographic purity are separate determinations and a certificate…
[2026 update] Interpreting a result that disagrees with the supplier's certificate Replied, post #38 · Sourcing › Independent verification · 24 Jun 2026 · 0 likes Verification records are dated because they expire in usefulness. A result from two years ago describes a lot from two years ago.
Endotoxin and why it is a separate question from purity — what changed since Replied, post #55 · Analytics › Impurities & related substances · 23 Jun 2026 · 0 likes Adding a null result on Endotoxin. I looked, carefully, and found nothing, and null results deserve posting precisely because they never are.
Prescription portability between countries Replied, post #72 · Access › International · 21 Jun 2026 · 0 likes Country-by-country legality: compound approval and legal status differ substantially by jurisdiction. Semaglutide approved in the United States and European Union;…
[2026 update] Area percent versus weight percent: the confusion that causes most arguments Replied, post #59 · Analytics › HPLC & UHPLC · 17 Jun 2026 · 12 likes An observation about Area percent versus weight percent that I cannot explain and am posting anyway, on the principle that unexplained observations are more useful…
Type 2 diabetes and the largest part of the evidence base — does this still hold? Replied, post #15 · Clinical › Comorbidities · 17 Jun 2026 · 0 likes Interactions between comorbidities: diabetes and kidney disease together change the risk calculation for hypoglycemia and for medication clearance. They are not…
An appeal that succeeded, with the letter structure — the long version Replied, post #93 · Access › Insurance & coverage · 13 Jun 2026 · 23 likes Post #92 is the version of this I will quote in future. One addition. I think the appeal question is answerable and has not been answered, which is a more optimistic…
Injecting into an area that has become firm: why not to Replied, post #34 · Practice › Administration · 8 Jun 2026 · 0 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. Noting…
Reading a trial's population section before its results Replied, post #75 · Evidence › Trials · 1 Jun 2026 · 28 likes Coming back to post #73, because the follow-up matters more than the original answer. An open-label trial is not worthless and its subjective endpoints deserve more…
Follow-up: A parcel that arrived warm: a decision process, not a verdict Replied, post #48 · Practice › Storage & stability · 29 May 2026 · 30 likes Visible particulate is a strong signal in the other direction: it is a reason to stop and ask rather than to filter and proceed. Nothing above should be read as advice…
[2026 update] Storing lyophilised material long term: what governs the shelf life Replied, post #124 · Practice › Storage & stability · 28 May 2026 · 19 likes If someone has run Storing lyophilised material long term properly I would rather read that than my own reconstruction of it. Posting mine only because the thread has…
Revisiting: Primary endpoint hierarchies and why order matters Started this topic · Evidence › Trials · 3 May 2026 · 43 likes Posting this under the heading it deserves: Revisiting: Primary endpoint hierarchies and why order matters Everything below is what sits behind that. I was wrong about…
Semaglutide and gastric emptying — the mechanism behind most of the side-effect profile Replied, post #14 · Compounds › Semaglutide · 2 May 2026 · 24 likes Post #13 answers the question as asked. The question underneath it is different. On alcohol: the labelling does not contraindicate it, but it raises gastric irritation…
Why oral semaglutide needs an absorption enhancer at all — one year on Replied, post #11 · Compounds › Oral incretins · 17 Apr 2026 · 9 likes The thirty-minute wait before eating is not conservatism. Food in the stomach materially reduces absorption of the oral product, and the instruction exists because the…
Subgroup analyses: pre-specified versus discovered — a second dataset Replied, post #46 · Evidence › Trials · 15 Apr 2026 · 0 likes Post #44 and I disagree about the size of the effect, not about the direction. Offering a way to settle Subgroup analyses rather than another opinion about it. Two…
[2026 update] 0.3 mL versus 0.5 mL versus 1 mL barrels: resolution matters Replied, post #24 · Devices › Syringes & needles · 12 Apr 2026 · 0 likes Adding a null result on 0.3 ml versus 0.5 ml. I looked, carefully, and found nothing, and null results deserve posting precisely because they never are.
The "under review" status pill and when a moderator applies it Replied, post #59 · Evidence › Preprints · 7 Apr 2026 · 16 likes Post #57 and I disagree about the size of the effect, not about the direction. A preprint with the data and code attached is frequently more checkable than a published…
Stepping down deliberately, and how to do it without losing progress Replied, post #86 · Practice › Dosing & titration · 4 Apr 2026 · 8 likes This follows post #85 rather than contradicting it. Concentration and dose get conflated constantly in this subcategory. Changing how much diluent you add changes the…
Journal club: is percentage weight change the right endpoint? Replied, post #32 · Evidence › Journal club · 2 Apr 2026 · 0 likes Sessions on negative or null results are consistently the most instructive and the hardest to get anyone to attend.
Managing an unplanned gap in supply Replied, post #75 · Access › Shortages · 27 Mar 2026 · 0 likes Post #74 answers the question as asked. The question underneath it is different. Shortage-driven price movement is real and is a separate question from availability.…
Choosing which test to pay for, given a fixed budget Replied, post #28 · Sourcing › Independent verification · 17 Mar 2026 · 3 likes Repeat determination on the same product line months apart is the measurement that speaks to consistency, and consistency is what most buyers actually want. The…
Measurement error in home scales, with a worked standard deviation Replied, post #25 · Research Methods › Statistics · 16 Mar 2026 · 15 likes The most common statistical error in this community is not technical: it is treating a self-selected collection of reports as a sample from a population.
Second pass at: What "verified" means on our vendor pages, stated narrowly Replied, post #78 · Sourcing › Vendor reports · 7 Mar 2026 · 0 likes Dosing and purity: a vial that is 99% pure might contain 80% of its label claim if the other mass is water, counter-ion, and excipient. Purity and content are…
A history of disordered eating: proceeding carefully Replied, post #75 · Wellbeing › Mental health · 27 Jan 2026 · 0 likes On history of disordered eating 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…
The headache that turns out to be dehydration Replied, post #146 · Nutrition & Training › Hydration & electrolytes · 20 Jan 2026 · 5 likes Post #142 describes the usual case. This is about the unusual one. Headache is well covered in the tag pages, and the older discussions are better than the recent ones…
Rotating between abdomen, thigh and upper arm: absorption differences — one year on Replied, post #10 · Practice › Administration · 17 Jan 2026 · 1 like Subcutaneous injection into abdominal tissue, thigh or upper arm is what the licensed labelling in this class describes, and the published comparisons found the…
Request: a diff view for wiki revisions — the long version Replied, post #99 · Meta › Feature requests · 14 Jan 2026 · 0 likes Right, and stated more narrowly than I would have dared to state it.
Anxiety in the first weeks: drug, situation, or both — what changed since Replied, post #71 · Wellbeing › Mental health · 2 Jan 2026 · 5 likes Taking Anxiety seriously for a moment rather than deflecting: the honest position is that the community has observations and no controlled comparison, and those two…
Reading SURMOUNT-1 without the press release Replied, post #122 · Compounds › Tirzepatide · 31 Dec 2025 · 27 likes Small methodological point on reading SURMOUNT-1 without the press: repeating a measurement is cheap and resolves most of what is being argued about here at no cost to…
Why an oral GLP-1 agonist is a formulation achievement more than a chemistry one Replied, post #104 · Compounds › Oral incretins · 22 Dec 2025 · 27 likes That reframing is the whole thing. The facts I already had.
Freeze-thaw and why one cycle is not the same as five Replied, post #23 · Practice › Storage & stability · 15 Nov 2025 · 0 likes Post #20 answers the question as asked. The question underneath it is different. A methods point on freeze-thaw rather than a substantive one: if the comparison is not…
Where to report an adverse event officially, by region — a second dataset Replied, post #114 · Safety › Adverse events · 10 Nov 2025 · 0 likes Saving this. It is the version I will quote when the question comes round again.
High-resolution MS on aggregates and what it can see Replied, post #114 · Analytics › Mass spectrometry · 7 Nov 2025 · 11 likes Everything in post #110 holds. The case it does not cover is the one I have. What I would check first on high-resolution is whether the thing being measured moved or…
Coming back to: Resolution and tailing factor: real acceptance criteria Replied, post #109 · Analytics › HPLC & UHPLC · 16 Oct 2025 · 33 likes Post #105 put the caveat in the right place and I want to underline it. Answering the Resolution and tailing factor question as asked, then the question I think is…
What the GIP component of tirzepatide is thought to contribute, and how confident we can… Replied, post #52 · Compounds › Tirzepatide · 10 Oct 2025 · 3 likes Post #49 is the version of this I will quote in future. One addition. The GIP component: GIP receptor agonism is thought to amplify the GLP-1 effect on satiety and…
Power cut for eleven hours: how I assessed it afterwards Replied, post #86 · Practice › Storage & stability · 7 Oct 2025 · 17 likes Coming back to post #82, because the follow-up matters more than the original answer. Power cut for eleven hours looks different depending on whether you are reading…
Citing a preprint in a maintained document: our rule and its reasoning — does this still… Replied, post #101 · Evidence › Preprints · 3 Oct 2025 · 0 likes This follows post #98 rather than contradicting it. Reading a preprint properly means doing some of the reviewer's job: methods first, then whether the analysis matches…
Reading a supplier's product description as a marketing document Replied, post #78 · Compounds › Other compounds · 2 Oct 2025 · 17 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…
Second pass at: Programming during a large energy deficit Replied, post #19 · Nutrition & Training › Resistance training · 26 Sep 2025 · 0 likes Worth separating Programming during a large energy as a question about the compound from Programming during a large energy as a question about the documentation. They…
Payment method and the leverage it gives you, ranked Replied, post #75 · Sourcing › Payments · 25 Sep 2025 · 0 likes Answering the question post #71 raises rather than the one it answers. Chargeback reality: if you pay by credit card and the supplier does not deliver, you can attempt…
Where the integrator drew the baseline, and how much it moved the number Replied, post #9 · Analytics › HPLC & UHPLC · 21 Sep 2025 · 0 likes Where the baseline is drawn is the least documented and most consequential choice in the whole determination. Valley-to-valley, tangent skim and forced-to-zero can span…
Coming back to: Where the integrator drew the baseline, and how much it moved the number Started this topic · Analytics › HPLC & UHPLC · 12 Sep 2025 · 0 likes On the subject in the title: Where the integrator drew the baseline, and how much it moved the number Working notes rather than a conclusion. Posting the method first,…
About the Site feedback category Replied, post #4 · Meta › Site feedback · 10 Sep 2025 · 6 likes Suggestion for the wiki post above: it would be worth linking the two or three most-referenced topics in this category directly, since new members reliably ask for…
Adolescents: a distinct evidence base — one year on Replied, post #14 · Clinical › Special populations · 5 Sep 2025 · 20 likes Two claims get bundled together under Adolescents and they need separating. The descriptive one — this is what was observed — is usually well supported. The causal one…
Tirzepatide molecular mass and the charge states you would expect on ESI Replied, post #9 · Compounds › Tirzepatide · 24 Aug 2025 · 5 likes Gastrointestinal effects were comparable in character to the GLP-1 monoagonists across the programme. Individual reports here vary in both directions, which is what you…
Fatigue in the first month: how much is the drug and how much is intake — what changed… Replied, post #32 · Practice › Side effects · 13 Aug 2025 · 4 likes I read post #30 twice before replying, because I had assumed the opposite. Lean mass loss: the rate of lean tissue loss depends on protein intake, resistance training…
Travel coolers and how long they really hold Replied, post #80 · Devices › Cold chain · 8 Aug 2025 · 24 likes Travel coolers: I would want to see the raw numbers rather than the summary before agreeing. Summaries lose exactly the information that would settle this.
Reading a combination trial: attributing effect to components Replied, post #2 · Compounds › Cagrilintide & amylin analogues · 8 Aug 2025 · 33 likes Saving this. It is the version I will quote when the question comes round again.
Promotion criteria, and the one that stops most nominations — the long version Replied, post #37 · Documentation › Doc review · 7 Aug 2025 · 22 likes Coming back to post #33, because the follow-up matters more than the original answer. Point three stops most nominations. A document without a maintainer becomes wrong…
What a documentation review can and cannot tell you Replied, post #53 · Sourcing › Independent verification · 30 Jul 2025 · 0 likes A record with four results over sixteen months is a thin record rather than a bad one, and the honest description says which. Speaking for myself and not for anyone…
Trial registration and comparing the protocol with the paper Replied, post #20 · Evidence › Trials · 8 Jul 2025 · 12 likes Everything in post #18 holds. The case it does not cover is the one I have. Registration before enrolment, with the primary endpoint declared, is what makes outcome…
Foaming during reconstitution and whether it matters Replied, post #18 · Practice › Reconstitution · 3 Jul 2025 · 26 likes Do not shake. Swirl, or leave it. Vigorous agitation introduces air and shear, and neither helps a peptide go into solution any faster than patience does.
Coming back to: Official shortage notices and what they authorise Replied, post #23 · Access › Shortages · 6 Jun 2025 · 23 likes Reports that a pharmacy has stock are the least durable information on the site and are still worth posting with a date. I have written this out at length because the…
Pre-registering a personal experiment, seriously Replied, post #74 · Research Methods › N-of-1 designs · 1 Jun 2025 · 3 likes Regression to the mean explains a great many personal experiments. People start when things are at their worst, and things at their worst tend to improve. It is worth…
Half-life, steady state, and accumulation worked through Replied, post #27 · Pharmacology › Pharmacokinetics · 26 May 2025 · 9 likes I disagree with the framing of half-life above, and I think it is a substantive disagreement rather than a terminological one. Setting out why, so it can be checked.…
A 5 mg vial and a 0.25 mg dose: the arithmetic in full — the long version Replied, post #117 · Practice › Reconstitution · 26 May 2025 · 0 likes 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…
Asking about a compound your prescriber has not heard of Replied, post #47 · Clinical › Prescriber conversations · 24 May 2025 · 0 likes Everything in post #43 holds. The case it does not cover is the one I have. Bringing a record of symptoms with dates and severities makes an assessment materially…
DXA precision and the least significant change for lean mass — the long version Replied, post #49 · Outcomes › Body composition · 16 May 2025 · 0 likes The strongest argument against my own position on DXA precision, stated as well as I can state it, since nobody else has yet.
[2026 update] What the GIP component of tirzepatide is thought to contribute, and how… Replied, post #55 · Compounds › Tirzepatide · 16 May 2025 · 0 likes Building on post #52 rather than restating it. The GIP component: GIP receptor agonism is thought to amplify the GLP-1 effect on satiety and energy expenditure, but how…
Journal club: SURMOUNT-1, read without the press release Replied, post #113 · Evidence › Journal club · 9 May 2025 · 10 likes SELECT (N Engl J Med 2023): Semaglutide cardiovascular outcomes without diabetes. The first outcome trial in people without diabetes, which decoupled the cardiovascular…
Journal club: STEP 1 and the treatment-policy estimand — does this still hold? Replied, post #66 · Evidence › Journal club · 20 Apr 2025 · 31 likes Noted, and I have changed what I was going to do on the strength of it.
Reading order for a first week here, and what to skip until later Replied, post #86 · Start Here › Welcome · 16 Apr 2025 · 16 likes What I want from this reading order thread is the list of things that would need to be true for the claim to hold. If we can write that list, we can check it.
Adjudicated events and why the definition matters — the long version Replied, post #84 · Evidence › Trials · 6 Apr 2025 · 0 likes Fair, and the limits you put on it are the part I will remember.
What SELECT changed about how semaglutide is discussed, and what it did not Replied, post #60 · Compounds › Semaglutide · 1 Apr 2025 · 11 likes On identity confirmation: a mass close to 4113.6 Da on the intact molecule is consistent with semaglutide and is also consistent with several closely related species.…
[2026 update] US compounding rules and how they changed Replied, post #3 · Regional › North America · 8 Mar 2025 · 28 likes The opening post and I disagree about the size of the effect, not about the direction. The denial letter is the specification for the appeal. It states a criterion and…
Distinguishing a deletion sequence by mass alone Replied, post #98 · Analytics › Mass spectrometry · 17 Feb 2025 · 3 likes Response in electrospray is not proportional to abundance across different species. Using peak intensities from a mass spectrum to estimate proportions is a mistake…
Random versus fixed effects: choosing rather than defaulting — a second dataset Replied, post #105 · Evidence › Meta-analyses · 13 Feb 2025 · 4 likes An honest declaration on Random versus fixed effects: I have a prior here and it is strong enough that you should weight what I say downward. Stating it rather than…
Isotonicity and what happens when you get it wrong Replied, post #29 · Pharmacology › Formulation chemistry · 15 Jan 2025 · 18 likes Isotonicity is well covered in the tag pages, and the older discussions are better than the recent ones because they were argued out properly. Worth twenty minutes…
Books and papers worth reading that are not about this at all Replied, post #13 · Lounge › Off topic · 6 Jan 2025 · 9 likes A definition problem is doing most of the work in this books and papers discussion. Once the term is pinned down I suspect the disagreement mostly goes away and what is…
Sample size intuition for a personal experiment Replied, post #4 · Research Methods › Statistics · 30 Dec 2024 · 19 likes Answering the question the opening post raises rather than the one it answers. The most common statistical error in this community is not technical: it is treating a…
Coming back to: When to suspect the method rather than the sample Replied, post #136 · Analytics › Method validation · 26 Dec 2024 · 0 likes Transfer between laboratories: a method can be transferred from one lab to another, but the receiving lab needs to demonstrate that they can achieve the same…
Persistent vomiting and the threshold for seeking help — one year on Replied, post #21 · Safety › Adverse events · 20 Dec 2024 · 0 likes That is consistent with mine, for whatever one more account is worth.
Building a sensible monitoring schedule with your prescriber Replied, post #41 · Clinical › Bloodwork · 20 Dec 2024 · 13 likes Adding a reference point for building a sensible monitoring schedule. Mine is a single case, collected without controls, and I am posting the method alongside it so it…
[2026 update] New subcategory: rationale and scope Replied, post #22 · Meta › Announcements · 25 Nov 2024 · 8 likes Genuine question rather than a rhetorical one: has anyone here actually observed New subcategory, as opposed to read about it? The thread is long and I cannot tell.
Reading a preclinical wound-healing model and its relevance to a human tendon Replied, post #82 · Compounds › Repair & healing peptides · 18 Nov 2024 · 19 likes Reading a preclinical wound-healing model: the model shows whether a mechanism is plausible in a specific context. It does not show magnitude of effect in humans, does…
Research-use-only labelling: what it means and what it does not — the long version Replied, post #12 · Sourcing › Regulatory · 16 Oct 2024 · 2 likes The arithmetic in post #9 is right; the assumption feeding it is the part to check. An indication approved for one age range does not extend to another, and paediatric…
Irish differences from the UK position Replied, post #31 · Regional › UK & Ireland · 10 Oct 2024 · 10 likes Post #27 put the caveat in the right place and I want to underline it. Correcting an out-of-date claim in this subcategory with a source and a date is more valuable…
Progressive overload when the scale is falling — one year on Replied, post #76 · Nutrition & Training › Resistance training · 21 Sep 2024 · 0 likes Nothing to add, except that this is the answer I would give if asked.
Circumference measurements as a poor man's composition estimate Replied, post #104 · Outcomes › Body composition · 28 Aug 2024 · 3 likes Right, and stated more narrowly than I would have dared to state it.
Second pass at: A field-by-field walk through a certificate of analysis Replied, post #38 · Analytics › COA interpretation · 27 Aug 2024 · 0 likes Reading old certificates: if a certificate is dated years ago, the lot it describes might be old. That is not automatically a problem but it is worth noting. Fresh…
Reporting a discrepancy without making an allegation Replied, post #32 · Sourcing › Vendor reports · 18 Aug 2024 · 31 likes Building on post #29 rather than restating it. Dosing and purity: a vial that is 99% pure might contain 80% of its label claim if the other mass is water, counter-ion,…
Coming back to: Purity assay versus content assay: two different numbers Replied, post #60 · Analytics › COA interpretation · 13 Aug 2024 · 15 likes What I can speak to on Purity assay versus content assay is narrow, so I will keep it narrow rather than generalising from it. Beyond that boundary I do not know.
Guidelines revision: what changed and why Replied, post #3 · Meta › Announcements · 24 Jul 2024 · 1 like Right — I had this wrong and I am glad to have read it before it mattered.
Cold packs, phase-change material, and what survives ten days Replied, post #19 · Sourcing › Logistics · 16 Jun 2024 · 16 likes Confirming post #16 from a second method, which matters more than confirming it from a second person. At what point is a parcel genuinely a problem: if it was…