e.pires

TL2 · Uppsala

Contributes reviews on supplier material. Based in Uppsala.

Joined 21 August 2025 · last posted 23h

84 posts, newest first. Showing up to 150.

What a reversed-phase purity number actually is Replied, post #99 · Analytics › HPLC & UHPLC · 27 Jul 2026 · 1 like Reversed-phase purity number has a well-known answer and a correct answer, and the interesting work is establishing that they are the same. Nobody has done that here yet.
What to bring: records that a clinician can actually use Replied, post #19 · Clinical › Prescriber conversations · 26 Jul 2026 · 18 likes Nothing to add, except that this is the answer I would give if asked.
Named, unnamed and unspecified impurities as regulatory categories — the long version Replied, post #115 · Analytics › Impurities & related substances · 26 Jul 2026 · 18 likes Aggregates: multiples of the monomer mass. May not elute at all under a standard reversed-phase method. A species that does not come off the column does not appear in…
Muscle cramps: the ordinary causes before the exotic ones — a second dataset Replied, post #75 · Practice › Side effects · 25 Jul 2026 · 1 like Coming back to post #71, because the follow-up matters more than the original answer. The published rates come from populations that were titrated on a defined schedule…
Reading U-100 graduations, with a conversion table Replied, post #41 · Devices › Syringes & needles · 22 Jul 2026 · 21 likes Sharps containers are a legal requirement for disposal in several jurisdictions and a sensible precaution everywhere. A rigid sealed container is the minimum. Happy to…
Asking a follow-up: new topic or new reply? Replied, post #62 · Start Here › How to Ask · 20 Jul 2026 · 14 likes Since asking a follow-up keeps coming up, it should probably be a maintained page rather than a recurring thread. I am happy to draft it if someone with more direct…
Revisiting: The report format the maintainers ask for, and why each field is there Replied, post #103 · Sourcing › Vendor reports · 17 Jul 2026 · 32 likes Photograph the vial and the label before opening. It costs ten seconds and it is what turns a report into something checkable. On balance I think that is right, and I…
Review: a draft on reconstitution arithmetic, with objections — one year on Replied, post #44 · Documentation › Doc review · 14 Jul 2026 · 9 likes The four criteria are that the question recurs, that the content is correct and sourced or labelled as community practice, that somebody will be named as maintainer…
Request: a per-category review queue Replied, post #85 · Meta › Feature requests · 7 Jul 2026 · 0 likes Per-category review queue looks different depending on whether you are reading the primary literature or the summaries of it, and the difference is not in our favour.
How much context is too much context in a first post? Replied, post #22 · Start Here › How to Ask · 6 Jul 2026 · 19 likes Adding the measurement that post #21 says would settle it. When you quote a figure from somewhere else, say where from. Not as a formality — the answer frequently…
A single out-of-range value on an otherwise normal panel Replied, post #67 · Clinical › Bloodwork · 2 Jul 2026 · 9 likes Rate of change is frequently more informative than absolute value, and it is only available if the earlier results were kept. Two sources, same conclusion, and I could…
Pages past their review date, listed — does this still hold? Replied, post #19 · Meta › Wiki maintenance · 20 Jun 2026 · 0 likes Adding what did not work for me on Pages past, since the failures never get written up and they are half the useful information.
Coming back to: Time to steady state after a dose increase Replied, post #81 · Pharmacology › Pharmacokinetics · 20 Jun 2026 · 5 likes Steady state is approached in roughly four to five half-lives. For a compound with a week-long half-life that is four to five weeks, which is where the escalation…
Follow-up: The retatrutide phase 2 obesity paper, read closely Replied, post #18 · Compounds › Retatrutide · 16 Jun 2026 · 26 likes On post #14 — agreed on the reasoning, with one qualification. Hepatic effects: glucagon receptor agonism promotes hepatic fat oxidation, which is mechanistically…
Pooling trials with different estimands Replied, post #19 · Evidence › Meta-analyses · 11 Jun 2026 · 1 like Answering the question post #15 raises rather than the one it answers. Subgroup meta-analysis multiplies the usual subgroup problems by the number of included trials.…
A reconstituted vial's beyond-use date and the reasoning behind common figures Replied, post #53 · Practice › Storage & stability · 5 Jun 2026 · 4 likes Freezing a reconstituted peptide solution is not automatically protective. Freeze-thaw cycling is one of the harsher things you can do to a protein in solution, and a…
An appeal that succeeded, with the letter structure — the long version Replied, post #32 · Access › Insurance & coverage · 30 May 2026 · 12 likes Where an exception process exists separately from an appeal, they are different routes with different criteria and using the wrong one loses time. Two people can read…
Comparing prices across jurisdictions without misleading yourself Replied, post #13 · Access › Pricing · 28 May 2026 · 7 likes Post #12 is the version of this I will quote in future. One addition. I have no financial interest in anything named in this thread and I want to say so before I…
[2026 update] 0.3 mL versus 0.5 mL versus 1 mL barrels: resolution matters Replied, post #123 · Devices › Syringes & needles · 15 May 2026 · 0 likes U-100 means the barrel is graduated for a solution containing one hundred units of insulin per millilitre. For anything that is not insulin, the units are simply…
Reading a trial's population section before its results Replied, post #20 · Evidence › Trials · 14 May 2026 · 2 likes Discontinuation handling is the methodological detail that most changes a result and gets the least attention. Read how missing data was imputed before reading the…
Revisiting: What pooling buys you and what it destroys Replied, post #18 · Evidence › Meta-analyses · 10 May 2026 · 22 likes Acknowledging rather than arguing. The reasoning holds as far as I can follow it.
Designing a personal experiment that could change your mind — one year on Replied, post #32 · Research Methods › N-of-1 designs · 12 Apr 2026 · 6 likes A single-person experiment can be genuinely informative if it has a pre-specified outcome, a defined period, and a plan written before the data arrives. Most accounts…
Follow-up: Evidence quality in the secretagogue literature: an honest assessment Replied, post #24 · Compounds › Secretagogues & GH axis · 5 Apr 2026 · 26 likes Answering the question post #23 raises rather than the one it answers. Published human data on most of this family is thin, old, or from small studies with surrogate…
Revisiting: Journal club: SURMOUNT-1, read without the press release Replied, post #31 · Evidence › Journal club · 1 Apr 2026 · 4 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.
Molecular mass of semaglutide and why the figure differs between sources Replied, post #19 · Compounds › Semaglutide · 15 Mar 2026 · 7 likes Post #16 answers the question as asked. The question underneath it is different. Semaglutide's structure is a modified backbone with a C18 diacid attached through a…
What a certificate commits its issuer to — one year on Replied, post #29 · Analytics › COA interpretation · 9 Mar 2026 · 19 likes A chromatogram supplied as a small image is legible for peak shape and not for baseline detail. That is enough to sanity-check an integration and not enough to…
Sample size intuition for a personal experiment — does this still hold? Replied, post #6 · Research Methods › Statistics · 6 Mar 2026 · 4 likes Sample size determines what a study could have detected, not what it did. Reporting the detectable effect size makes a null result interpretable.
[2026 update] Amylin and gastric emptying: overlapping mechanisms with incretins Replied, post #15 · Compounds › Cagrilintide & amylin analogues · 1 Mar 2026 · 0 likes Confirming post #12 from a second method, which matters more than confirming it from a second person. Marking my uncertainty on Amylin and gastric emptying explicitly.…
Coming back to: Reading a supplier's product description as a marketing document Replied, post #32 · Compounds › Other compounds · 21 Feb 2026 · 31 likes On analysis: unusual or modified sequences are exactly where a default reversed-phase method is least likely to be appropriate. A supplier that runs everything on one…
Second pass at: The topic list is dense — is that deliberate? Replied, post #70 · Meta › Site feedback · 12 Feb 2026 · 0 likes Post #69 answers the question as asked. The question underneath it is different. The thing about topic list that took me longest to accept is that a plausible mechanism…
[2026 update] A rising related-substance total over six months: degradation or method… Replied, post #19 · Analytics › Impurities & related substances · 11 Feb 2026 · 0 likes Incomplete deprotection: mass higher by the protecting group mass. Usually markedly later eluting. A synthesis artifact from incomplete removal of protecting groups.
Follow-up: A supplier that answers analytical questions with restated claims Replied, post #80 · Sourcing › Red flags · 6 Feb 2026 · 13 likes Second-hand on supplier, so weight it accordingly — someone whose method I trust told me this and I have not verified it myself.
[2026 update] Long-time reader, first-time poster Replied, post #46 · Lounge › Introductions · 30 Jan 2026 · 1 like Community culture: introductions give you a sense of who is here. Reading a few introduces you to the people and the tone of the community. This is the sort of thing…
Whether protein timing matters at a large deficit Replied, post #18 · Nutrition & Training › Protein & intake · 20 Jan 2026 · 0 likes Distribution across the day appears to matter less than total for most outcomes, and it matters practically because a single large meal is harder when appetite is…
Run-in periods and the population they select Replied, post #43 · Evidence › Trials · 31 Dec 2025 · 3 likes Agreed on run-in periods, with one qualification that I think matters. The reasoning holds for the case as described. Change the starting assumption and it does not,…
Vomiting: when it is expected and when it is a reason to stop Replied, post #50 · Practice › Side effects · 28 Dec 2025 · 2 likes The published rates come from populations that were titrated on a defined schedule with clinical supervision. Rates from a forum are not comparable and are biased by…
Micro-titration: a disputed topic, argued properly Replied, post #15 · Practice › Dosing & titration · 24 Dec 2025 · 8 likes Seconded. It reads as careful rather than confident, which is the right register.
The decimal-point error, and the habit that catches it Replied, post #109 · Practice › Reconstitution · 18 Dec 2025 · 4 likes The arithmetic in post #108 is right; the assumption feeding it is the part to check. The reason decimal-point error keeps being re-asked is that the answer is…
The decimal-point error, and the habit that catches it Replied, post #72 · Practice › Reconstitution · 16 Dec 2025 · 5 likes Answering the question post #70 raises rather than the one it answers. A definition problem is doing most of the work in this decimal-point error discussion. Once the…
Stepping down deliberately, and how to do it without losing progress Replied, post #23 · Practice › Dosing & titration · 4 Dec 2025 · 1 like 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…
Common supplements people ask about, assessed one at a time — a second dataset Replied, post #15 · Practice › Interactions · 3 Dec 2025 · 2 likes Mechanistic reasoning about interactions has a poor predictive record. It is a good way to generate a question and a bad way to answer one.
Pen dose counters: what a click does and does not guarantee Replied, post #80 · Devices › Pens & autoinjectors · 18 Nov 2025 · 31 likes Needle changes between doses are specified for a reason and the reasons are dose accuracy and sterility rather than comfort alone.
A parcel that arrived warm: a decision process, not a verdict Replied, post #140 · Practice › Storage & stability · 15 Nov 2025 · 26 likes Narrowing post #139, because the general version has more than one answer. Visible particulate is a strong signal in the other direction: it is a reason to stop and ask…
Second pass at: Circumference measurements as a poor man's composition estimate Replied, post #9 · Outcomes › Body composition · 26 Oct 2025 · 16 likes On post #7 — agreed on the reasoning, with one qualification. Adding a reference point for Circumference measurements. Mine is a single case, collected without…
Reverse causation in a cohort study of weight and outcome — a second dataset Replied, post #51 · Evidence › Study critique · 14 Sep 2025 · 0 likes Reframing Reverse causation slightly, because I think the disagreement is about the question rather than the answer. If the question is "does it happen", yes. If it is…
Liver enzymes drifting down and what that usually means Replied, post #11 · Clinical › Bloodwork · 14 Sep 2025 · 32 likes Fine by me. I had wanted a stronger conclusion and there is not one available.
Journal club: STEP-HFpEF and symptom endpoints Replied, post #2 · Evidence › Journal club · 30 Aug 2025 · 12 likes Taking the opening post at face value and following it one step further. Small methodological point on step-hfpef and symptom endpoints: repeating a measurement is…
How to research a compound with no human data without deceiving yourself Replied, post #20 · Compounds › Other compounds · 30 Jul 2025 · 0 likes This subcategory exists because some people will research compounds outside the main groups discussed here. The standard of evidence and honesty about its limits…
Reaching a dose and staying there for a year: a longitudinal note — does this still hold? Replied, post #13 · Practice › Dosing & titration · 17 Jul 2025 · 0 likes Steady state means the plasma concentration is stable from dose to dose. That happens around 4 to 5 half-lives. Before that, the concentration is rising with each dose.…
What this community means by "a source", in practical terms Replied, post #20 · Start Here › Welcome · 30 Jun 2025 · 0 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…
Which panel is worth repeating and which is worth ignoring Replied, post #48 · Clinical › Bloodwork · 28 Jun 2025 · 0 likes The honest answer on panel is that it depends, and the useful part is the list of what it depends on. Four items, in rough order of how much they matter. Most people…
Forced degradation studies: designing one that is informative — does this still hold? Replied, post #18 · Analytics › Method validation · 18 Jun 2025 · 0 likes The limit of quantitation determines what the impurity table can honestly contain. Peaks below it can be reported as detected and cannot be reported as a number.
A report I filed that turned out to be wrong, and the correction Replied, post #103 · Sourcing › Vendor reports · 15 Jun 2025 · 0 likes Confirming post #100 from a second method, which matters more than confirming it from a second person. Structured report format: compound, lot, independent testing…
[2026 update] Constipation management, with a dietitian's contribution Replied, post #3 · Practice › Side effects · 4 Jun 2025 · 0 likes I had written a reply contradicting the opening post and deleted it. Here is what survived. Recognition and grading: nausea ranges from "noticeable" to "limiting".…
Why oral semaglutide needs an absorption enhancer at all Replied, post #8 · Compounds › Oral incretins · 25 May 2025 · 11 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…
Travel coolers and how long they really hold — the long version Replied, post #23 · Devices › Cold chain · 23 May 2025 · 4 likes The interaction between cold chain and the storage question is that a warm transit spends part of the material's stability budget before it reaches you, and the budget…
Titles that describe the question, not the situation Replied, post #11 · Start Here › How to Ask · 15 May 2025 · 11 likes Timeline questions need the timeline. Dates, in order, with what happened on each. "A while ago" and "recently" are the two least useful words in a question of this kind.
Coming back to: Official shortage notices and what they authorise Replied, post #6 · Access › Shortages · 13 May 2025 · 32 likes Picking up post #5: that is the part I would want checked first. Official shortage notices sits at the boundary between what this community can usefully discuss and…
Reading an MS report that only gives you a single number Replied, post #67 · Analytics › Mass spectrometry · 1 May 2025 · 1 like This follows post #64 rather than contradicting it. Calibration state at the time of the run determines whether the ppm figure means anything. A report that states when…
Water content on a certificate and why it changes the arithmetic Replied, post #2 · Analytics › COA interpretation · 19 Apr 2025 · 2 likes Counterpoint on water content, offered without confidence: the same observation is consistent with a much duller explanation, and nobody has ruled the dull one out.
Coverage for the indication versus for the drug — a second dataset Replied, post #27 · Access › Insurance & coverage · 19 Mar 2025 · 29 likes Where coverage was granted, saying what the successful submission contained is one of the more useful posts on the site.
Pharmaceutical compounding rules, summarised from primary sources Replied, post #160 · Sourcing › Regulatory · 6 Mar 2025 · 8 likes Picking up post #159: that is the part I would want checked first. I changed my mind about pharmaceutical compounding rules after someone here asked me for the source…
Second pass at: Cross-border purchase within the EU: the actual rules Replied, post #77 · Access › International · 4 Mar 2025 · 0 likes Post #76 put the caveat in the right place and I want to underline it. Compounding in different countries: some countries allow pharmacy compounding under defined…
Journal club: SURMOUNT-OSA and a hard endpoint in a soft field Replied, post #19 · Evidence › Journal club · 2 Mar 2025 · 3 likes Sessions on negative or null results are consistently the most instructive and the hardest to get anyone to attend.
Counter-ion form: the field almost nobody reports — one year on Replied, post #13 · Analytics › COA interpretation · 20 Feb 2025 · 30 likes Post #11 describes the usual case. This is about the unusual one. I would call the community position on Counter-ion form likely rather than established, and I would be…
[2026 update] Lipid changes during rapid weight loss: the expected trajectory Replied, post #42 · Clinical › Bloodwork · 3 Feb 2025 · 24 likes On Lipid changes during rapid weight, the part that usually goes wrong is that the question is asked as though it has one answer. It has a range, and the width of the…
Research-use-only labelling: what it means and what it does not — the long version Replied, post #73 · Sourcing › Regulatory · 28 Jan 2025 · 17 likes Worth separating two things that post #71 runs together. Off-label use and medical practice: clinicians can prescribe approved medications off-label under some…
Second pass at: Regression to the mean in progress reports Replied, post #32 · Research Methods › Statistics · 22 Jan 2025 · 17 likes Noted, and I have changed what I was going to do on the strength of it.
Individual participant data versus aggregate data Replied, post #13 · Evidence › Meta-analyses · 1 Jan 2025 · 3 likes Post #9 put the caveat in the right place and I want to underline it. A note on how individual participant data versus aggregate gets discussed rather than on…
Follow-up: Tirzepatide's shorter half-life and its one practical consequence Replied, post #111 · Compounds › Tirzepatide · 26 Dec 2024 · 32 likes I had read the opposite somewhere and cannot now find where, which tells me something.
Anaesthesia and elective surgery: the aspiration question — does this still hold? Replied, post #14 · Practice › Interactions · 22 Dec 2024 · 0 likes Post #12 and I disagree about the size of the effect, not about the direction. The most useful reply I ever got about Anaesthesia and elective surgery was a request to…
Fixed versus detachable needles: the trade-offs Replied, post #54 · Devices › Syringes & needles · 16 Dec 2024 · 1 like Saving this. It is the version I will quote when the question comes round again.
Revisiting: Bug report: the reconstitution calculator and a rounding edge case Replied, post #20 · Data & Tools › Calculators · 15 Dec 2024 · 31 likes Helpful, and easy to find again, which is half of what a good reply is.
Triple agonism: additive, synergistic, or neither? Replied, post #2 · Compounds › Retatrutide · 4 Dec 2024 · 4 likes This follows the opening post rather than contradicting it. Agreed on triple agonism, with one qualification that I think matters. The reasoning holds for the case as…
Promotion criteria, and the one that stops most nominations Replied, post #114 · Documentation › Doc review · 16 Nov 2024 · 0 likes Promotion criteria came up in a thread eighteen months ago and was answered well. I cannot find it, which is itself the problem, so here is the reconstruction.
Reading a preclinical wound-healing model and its relevance to a human tendon Replied, post #25 · Compounds › Repair & healing peptides · 10 Nov 2024 · 13 likes Sensible. I would want the same detail before I acted on it either.
Second pass at: Hoarding and why it makes a shortage worse Replied, post #43 · Access › Shortages · 10 Oct 2024 · 2 likes Dose hold versus tapering: if a temporary shortage forces a gap, holding your dose and resuming when supply returns is different from gradually tapering. The two are…
Converting between mg/mL and units per dose, both directions Replied, post #35 · Practice › Reconstitution · 30 Sep 2024 · 22 likes I had written a reply contradicting post #31 and deleted it. Here is what survived. The best check on any reconstitution calculation is to do it twice by two different…
Follow-up: Where the four-week escalation interval comes from, and what it is not Replied, post #71 · Practice › Dosing & titration · 26 Sep 2024 · 4 likes Concentration and dose get conflated constantly in this subcategory. Changing how much diluent you add changes the volume you draw and changes nothing about the dose.
SURPASS-2 and the comparator dose question that will not go away Replied, post #22 · Compounds › Tirzepatide · 25 Sep 2024 · 0 likes Building on post #19 rather than restating it. Research-use-only tirzepatide is not approved for human use and is not made to pharmaceutical standards. Anyone…
Priming a pen and whether the primed volume is wasted — one year on Started this topic · Devices › Pens & autoinjectors · 14 Aug 2024 · 50 likes Posting this under the heading it deserves: Priming a pen and whether the primed volume is wasted — one year on Everything below is what sits behind that. I would like…
Second pass at: Retatrutide dose escalation in the published trials Replied, post #49 · Compounds › Retatrutide · 19 Jul 2024 · 22 likes On dose escalation: the published protocols escalated in defined steps over defined intervals, and those intervals were chosen to manage tolerability. Compressing them…
Second pass at: Journal club: LEADER as the historical anchor Replied, post #27 · Evidence › Journal club · 14 Jul 2024 · 18 likes Picking up post #26: that is the part I would want checked first. Adding a reference point for LEADER. Mine is a single case, collected without controls, and I am…
Oral contraceptives and delayed emptying: what the data shows Replied, post #23 · Practice › Interactions · 10 Jul 2024 · 0 likes Reframing oral contraceptives and delayed emptying slightly, because I think the disagreement is about the question rather than the answer. If the question is "does it…