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Unanswered questions

Questions with no answer at all. Not questions with no accepted answer — those are elsewhere.

741 questions · page 27 of 31

37 votes0 answers21k views
What should be in place before a first tirzepatide vial arrives from Shanghai?

The specifics, since they change the answer: tirzepatide · Shanghai. I am at the decision point and I would rather think it through than improvise. I would rather…

harm-reduction
harm-reduction

Reducing avoidable risk where a decision has already been made: independent verification before use, sterility practice, dose arithmetic checked…

445 questions
research-use-only
research-use-only

What "for research use only" means as a legal and practical designation: not approved for human use, no pharmacopoeial release testing, no…

91 questions
sterility
sterility

Sterility as a test result rather than an adjective. Covers what a sterility test actually measures, why "sterile filtered" on a document is close…

122 questions
asked by eighty_six_hours 16k · 2.0 years ago
28 votes0 answers34k views
Is ATTAIN-1 a fair comparison of ecnoglutide against its comparator arm?

For reference: ATTAIN-1 · ecnoglutide. I would like to know whether this claim survives contact with evidence. If the answer is "nobody has tested that", I would like…

clinical-trials
clinical-trials

Reading the primary literature properly: estimands, intention-to-treat versus per-protocol, confidence intervals, absolute versus relative…

913 questions
semaglutide
semaglutide

A GLP-1 receptor agonist with a fatty-acid-acylated backbone and a roughly one-week half-life, marketed for type 2 diabetes and for weight…

360 questions
tirzepatide
tirzepatide

A dual GIP and GLP-1 receptor agonist. Questions here cover the SURPASS and SURMOUNT programmes, the practical differences from a pure GLP-1…

162 questions
asked by noor_alhassan 15k · 2.0 years ago
32 votes0 answers16k views
Is a 0.22 µm syringe filter worth using on a reconstituted research vial?

This is the third vial from the same lot, so I can compare against two known-good ones. I would like to know whether this claim survives contact with evidence. If the…

sterility
sterility

Sterility as a test result rather than an adjective. Covers what a sterility test actually measures, why "sterile filtered" on a document is close…

122 questions
reconstitution
reconstitution

Taking a lyophilised vial to a solution of known concentration: choice of diluent, volume selection, how to add liquid without shearing the cake,…

330 questions
harm-reduction
harm-reduction

Reducing avoidable risk where a decision has already been made: independent verification before use, sterility practice, dose arithmetic checked…

445 questions
asked by carys_meredith 17k · 2.0 years ago
8 votes0 answers12k views
Is an escrowed payment sensible for an order shipping to Australia?

Conditions: an escrowed payment · Australia. The failure mode I am trying to avoid is making this decision emotionally. I have twelve months in view and I would like…

payment-privacy
payment-privacy

Payment mechanics and their privacy properties: why suppliers ask for stablecoin transfers, what an on-chain transfer reveals, confirmation…

31 questions
group-buy
group-buy

Pooled purchasing: how the economics work, what trust structure a pool needs, splitting a single tested lot, and the failure modes when the…

41 questions
international-shipping
international-shipping

Cross-border movement of research material: transit lanes and their thermal profiles, tracked versus untracked, declaration accuracy, and what…

427 questions
asked by haze_check 17k · 2.0 years ago
29 votes0 answers11k views
Is PIONEER-1 a fair comparison of tirzepatide against its comparator arm?

The case in front of me: PIONEER-1 · tirzepatide. The claim is plausible, which is exactly why I want to check it. I am able to read a paper if someone points me at…

clinical-trials
clinical-trials

Reading the primary literature properly: estimands, intention-to-treat versus per-protocol, confidence intervals, absolute versus relative…

913 questions
semaglutide
semaglutide

A GLP-1 receptor agonist with a fatty-acid-acylated backbone and a roughly one-week half-life, marketed for type 2 diabetes and for weight…

360 questions
tirzepatide
tirzepatide

A dual GIP and GLP-1 receptor agonist. Questions here cover the SURPASS and SURMOUNT programmes, the practical differences from a pure GLP-1…

162 questions
oral-glp1
oral-glp1

Oral routes for GLP-1 receptor agonism: peptide formulations rescued by absorption enhancers such as SNAC, and true small molecules that need no…

14 questions
asked by valentina_rossi 16k · 2.0 years ago
4 votes0 answers5.1k views
Does a DEXA repeated every two weeks give me an usable lean-mass trend?

I have three DEXA scans on the same scanner at twelve-week intervals, fasted, same time of day. The comparison I want does not seem to exist anywhere in a form I can…

dexa
dexa

Dual-energy X-ray absorptiometry: what it measures, its precision limits, why hydration state and scan positioning move the numbers, and how to…

84 questions
lean-mass
lean-mass

Lean body mass as measured rather than assumed: what DEXA, BIA and air-displacement plethysmography each actually estimate, the body-composition…

164 questions
muscle-loss
muscle-loss

Loss of contractile tissue during energy deficit: what fraction of total loss is lean mass, why the commonly quoted figures are measurement…

82 questions
asked by fibre_or_fragment 12k · 2.0 years ago
12 votes0 answers14k views
What did STEP 5 do with participants who could not tolerate a step?

I have been on a stable schedule for eleven weeks, so this is not a first-week question. This is presented as though it settles something, and I am not convinced it…

titration
titration

Stepwise dose increases over weeks, why the label schedules exist at all, and what tolerability-driven deviation from a schedule looks like in…

444 questions
clinical-trials
clinical-trials

Reading the primary literature properly: estimands, intention-to-treat versus per-protocol, confidence intervals, absolute versus relative…

913 questions
gi-side-effects
gi-side-effects

The gastrointestinal cluster as a whole - nausea, vomiting, diarrhoea, constipation, reflux, early satiety - with trial incidence rates, dropout…

416 questions
asked by second_lot 11k · 2.0 years ago
25 votes0 answers17k views
Is an HJ order from Tianjin likely to hold cold chain to the United Kingdom?

The case in front of me: HJ · Tianjin · the United Kingdom. I want to decide this in advance so that I am not deciding it under pressure later. Assume I will follow…

cold-chain
cold-chain

Keeping material within a temperature window from manufacture to use: phase-change packs versus dry ice, thermal mass, transit-lane temperature…

524 questions
international-shipping
international-shipping

Cross-border movement of research material: transit lanes and their thermal profiles, tracked versus untracked, declaration accuracy, and what…

427 questions
vendor-comparison
vendor-comparison

Side-by-side comparison of suppliers on measurable axes - independently confirmed purity and content, lead time, cold-chain handling,…

351 questions
asked by harriet_lonsdale 14k · 2.0 years ago
28 votes0 answers16k views
How do I document a six-month lifestyle-intervention requirement?

I have the plan documents and the written criteria, which took two calls to obtain. I have read the obvious sources and they disagree with each other, so I would…

prior-authorization
prior-authorization

Prior authorisation mechanics: medical-necessity criteria, documenting a lifestyle-intervention requirement, step therapy, and the…

19 questions
insurance
insurance

Coverage: formulary tiers, exclusion versus non-coverage, the difference a diabetes indication makes, employer carve-outs, and what an appeal…

35 questions
nutrition
nutrition

Eating on a suppressed appetite: hitting nutritional targets inside a small energy budget, micronutrient risk, meal structure, and what the trial…

92 questions
asked by tare_weight 47k · 2.0 years ago
13 votes0 answers12k views
Does dimerisation dominate for a GLP-1 receptor agonist held at 25 °C?

Stated plainly: dimerisation · a GLP-1 receptor agonist · 25 °C. The empirical answer seems settled. The explanation does not. If the honest answer is that nobody…

peptide-stability
peptide-stability

The chemistry of peptide degradation: deamidation, oxidation, hydrolysis, aggregation and fibrillation, and how temperature, pH, ionic strength,…

832 questions
storage
storage

Storage conditions and their evidence base: minus twenty degrees for powder, refrigerated for solution, protection from light, and what the…

646 questions
hplc
hplc

Reverse-phase high-performance liquid chromatography, the workhorse purity method. Column chemistry, mobile-phase choice, gradient slope,…

466 questions
asked by n_takahashi 36k · 2.0 years ago
21 votes0 answers30k views
Does fatigue at week seven of oral semaglutide usually resolve without a dose change?

Details up front: fatigue · seven · oral semaglutide. I can find plenty of assertions about this and almost no reasoning, which is usually a sign that nobody has…

gi-side-effects
gi-side-effects

The gastrointestinal cluster as a whole - nausea, vomiting, diarrhoea, constipation, reflux, early satiety - with trial incidence rates, dropout…

416 questions
titration
titration

Stepwise dose increases over weeks, why the label schedules exist at all, and what tolerability-driven deviation from a schedule looks like in…

444 questions
nausea
nausea

The dominant tolerability signal in every trial of the class: incidence, timing relative to a dose step, duration, and the distinction between…

346 questions
asked by Dr_Lena_Ostrowska 42k · 2.0 years ago
37 votes0 answers51k views
Is 3.33 mg/mL a sensible working concentration for orforglipron, or should I go lower?

Numbers first: 3.33 mg/mL · orforglipron. I want to know what the trade-off actually is rather than which option is fashionable. I would rather have a defensible…

diluent-volume
diluent-volume

Choosing how much diluent to add, which is really a question about what you want your measurement resolution to be. Larger volumes buy you…

308 questions
reconstitution
reconstitution

Taking a lyophilised vial to a solution of known concentration: choice of diluent, volume selection, how to add liquid without shearing the cake,…

330 questions
dosing-math
dosing-math

The arithmetic itself: milligrams to millilitres to insulin units, concentration after reconstitution, dose per draw, and vial-days per vial. Show…

811 questions
asked by linnea_wahlberg 14k · 2.0 years ago
14 votes0 answers14k views
How many vial-days does a 50 mg vial give at 1 mg/mL on a weekly schedule?

The particulars: 50 mg · 1 mg/mL. I would rather understand the derivation than memorise the outcome. Two people I asked gave two answers that differ by a factor of…

dosing-math
dosing-math

The arithmetic itself: milligrams to millilitres to insulin units, concentration after reconstitution, dose per draw, and vial-days per vial. Show…

811 questions
cost-analysis
cost-analysis

Cost arithmetic done honestly: cost per milligram after dead-space loss, list versus net price, comparing a multi-dose vial to a fixed-dose pen,…

261 questions
diluent-volume
diluent-volume

Choosing how much diluent to add, which is really a question about what you want your measurement resolution to be. Larger volumes buy you…

308 questions
asked by cap_the_luer 15k · 2.0 years ago
5 votes0 answers8.2k views
Does splitting a 20 mg weekly dose of a GLP-1 receptor agonist across two administrations change anything?

What I am working with: 20 mg · a GLP-1 receptor agonist. I keep seeing this stated as a fact with no explanation attached, and unexplained facts make me suspicious.…

split-dosing
split-dosing

Dividing a weekly dose across more than one administration. Questions here concern the pharmacokinetic rationale, whether the peak-to-trough ratio…

39 questions
dosing-math
dosing-math

The arithmetic itself: milligrams to millilitres to insulin units, concentration after reconstitution, dose per draw, and vial-days per vial. Show…

811 questions
glp1-mechanism
glp1-mechanism

Receptor-level pharmacology: GLP-1R as a class B GPCR, cAMP and PKA signalling, biased agonism, internalisation and resensitisation, and the…

175 questions
asked by ivo_paunovic 15k · 2.0 years ago
2 votes0 answers3.5k views
If I reconstitute a 2.5 mg vial with 1 mL of 0.9% sodium chloride, what concentration do I end up with?

Conditions: 2.5 mg · 1 mL · 0.9% sodium chloride. Please show the division. I want to check my own against yours. I would like the general form as well as the…

reconstitution
reconstitution

Taking a lyophilised vial to a solution of known concentration: choice of diluent, volume selection, how to add liquid without shearing the cake,…

330 questions
diluent-volume
diluent-volume

Choosing how much diluent to add, which is really a question about what you want your measurement resolution to be. Larger volumes buy you…

308 questions
dosing-math
dosing-math

The arithmetic itself: milligrams to millilitres to insulin units, concentration after reconstitution, dose per draw, and vial-days per vial. Show…

811 questions
asked by Dr_Jonas_Halvorsen 41k · 2.0 years ago
38 votes0 answers38k views
How does ERP compare to GL Biochem (Shanghai) on documentation quality?

Stated plainly: ERP · GL Biochem (Shanghai). Both of these get recommended confidently by different people, which suggests neither is obviously right. My constraints…

vendor-comparison
vendor-comparison

Side-by-side comparison of suppliers on measurable axes - independently confirmed purity and content, lead time, cold-chain handling,…

351 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

749 questions
vendor-vetting
vendor-vetting

Evaluating a supplier on evidence rather than reputation: testing history across batches, whether certificates are batch-specific, how failures…

436 questions
asked by carys_meredith 17k · 2.1 years ago
12 votes0 answers9.9k views
What does the mechanism of a GLP-1 receptor agonist predict that PIONEER-1 did not test?

Numbers first: a GLP-1 receptor agonist · PIONEER-1. I suspect the usual explanation for this is wrong, or at least incomplete. I am aware this may have a boring…

glp1-mechanism
glp1-mechanism

Receptor-level pharmacology: GLP-1R as a class B GPCR, cAMP and PKA signalling, biased agonism, internalisation and resensitisation, and the…

175 questions
clinical-trials
clinical-trials

Reading the primary literature properly: estimands, intention-to-treat versus per-protocol, confidence intervals, absolute versus relative…

913 questions
gip-receptor
gip-receptor

GIP receptor pharmacology, and the still-unsettled question of whether agonism or antagonism at GIPR is the metabolically useful direction.…

83 questions
asked by s_bhattacharya 42k · 2.1 years ago
24 votes0 answers22k views
What did the placebo arm of SURMOUNT-1 report for nausea?

What I have: SURMOUNT-1 · nausea. This is presented as though it settles something, and I am not convinced it does. I have two documents that appear to disagree,…

clinical-trials
clinical-trials

Reading the primary literature properly: estimands, intention-to-treat versus per-protocol, confidence intervals, absolute versus relative…

913 questions
gi-side-effects
gi-side-effects

The gastrointestinal cluster as a whole - nausea, vomiting, diarrhoea, constipation, reflux, early satiety - with trial incidence rates, dropout…

416 questions
nausea
nausea

The dominant tolerability signal in every trial of the class: incidence, timing relative to a dose step, duration, and the distinction between…

346 questions
thyroid
thyroid

Thyroid questions: the rodent C-cell findings behind the labelled warning, human calcitonin data, TSH drift during weight loss, and the…

14 questions
asked by lane_transit 42k · 2.1 years ago
29 votes0 answers11k views
Why do two papers on STEP 4 report different headline figures?

The clinician who ordered the panel was not concerned; I would still like to understand it. This is one of those things that everyone repeats and nobody derives. This…

clinical-trials
clinical-trials

Reading the primary literature properly: estimands, intention-to-treat versus per-protocol, confidence intervals, absolute versus relative…

913 questions
dosing-math
dosing-math

The arithmetic itself: milligrams to millilitres to insulin units, concentration after reconstitution, dose per draw, and vial-days per vial. Show…

811 questions
semaglutide
semaglutide

A GLP-1 receptor agonist with a fatty-acid-acylated backbone and a roughly one-week half-life, marketed for type 2 diabetes and for weight…

360 questions
oral-glp1
oral-glp1

Oral routes for GLP-1 receptor agonism: peptide formulations rescued by absorption enhancers such as SNAC, and true small molecules that need no…

14 questions
asked by ines_brandt 93k · 2.1 years ago
8 votes0 answers10k views
Can I reconstitute retatrutide at 8 mg/mL and still measure a small dose accurately?

What I am working with: retatrutide · 8 mg/mL. I am trying to build something sustainable rather than something thorough that I will abandon. I have already decided…

diluent-volume
diluent-volume

Choosing how much diluent to add, which is really a question about what you want your measurement resolution to be. Larger volumes buy you…

308 questions
insulin-syringe
insulin-syringe

U-100 and U-40 insulin syringes as measuring instruments. A U-100 syringe is graduated in insulin units where 100 units equals 1 mL, so one unit…

268 questions
dosing-math
dosing-math

The arithmetic itself: milligrams to millilitres to insulin units, concentration after reconstitution, dose per draw, and vial-days per vial. Show…

811 questions
asked by Dr_Otto_Lindqvist 38k · 2.1 years ago
24 votes0 answers19k views
Can I reconstitute a GLP-1 receptor agonist at 4 mg/mL and still measure a small dose accurately?

What I have: a GLP-1 receptor agonist · 4 mg/mL. This is a planning question. I know what my options are; I do not know how to weigh them. What I want is the minimum…

diluent-volume
diluent-volume

Choosing how much diluent to add, which is really a question about what you want your measurement resolution to be. Larger volumes buy you…

308 questions
insulin-syringe
insulin-syringe

U-100 and U-40 insulin syringes as measuring instruments. A U-100 syringe is graduated in insulin units where 100 units equals 1 mL, so one unit…

268 questions
dosing-math
dosing-math

The arithmetic itself: milligrams to millilitres to insulin units, concentration after reconstitution, dose per draw, and vial-days per vial. Show…

811 questions
asked by threadlock7 14k · 2.1 years ago
27 votes0 answers25k views
How does Homopeptide compare to Wuhan Wansheng Biotechnology on documentation quality?

The case in front of me: Homopeptide · Wuhan Wansheng Biotechnology. I would like the axes of comparison first and the recommendation second. I have tried the first…

vendor-comparison
vendor-comparison

Side-by-side comparison of suppliers on measurable axes - independently confirmed purity and content, lead time, cold-chain handling,…

351 questions
coa
coa

Certificates of analysis: what fields a useful one carries, how to tell a real analytical report from a marketing document, batch and lot…

749 questions
vendor-vetting
vendor-vetting

Evaluating a supplier on evidence rather than reputation: testing history across batches, whether certificates are batch-specific, how failures…

436 questions
asked by haze_check 17k · 2.1 years ago
5 votes0 answers4.4k views
How long does retatrutide stay within specification at 30 °C once reconstituted?

Stated plainly: retatrutide · 30 °C. This is a procedural question rather than a theoretical one, and I would like the procedure rather than the theory. What I have…

peptide-stability
peptide-stability

The chemistry of peptide degradation: deamidation, oxidation, hydrolysis, aggregation and fibrillation, and how temperature, pH, ionic strength,…

832 questions
storage
storage

Storage conditions and their evidence base: minus twenty degrees for powder, refrigerated for solution, protection from light, and what the…

646 questions
shelf-life
shelf-life

How long a preparation remains within specification: labelled expiry for a sealed lyophilised vial, beyond-use dating after reconstitution, and…

301 questions
asked by loss_on_drying 47k · 2.1 years ago
21 votes0 answers26k views
What is the reported incidence of vomiting at the top studied dose?

It has now persisted for three weeks, which is what moved this from tolerable to worth asking about. This is presented as though it settles something, and I am not…

vomiting
vomiting

Emesis as a reported adverse event: trial incidence, its relationship to dose escalation rate, dehydration risk, and when it stops being a…

14 questions
clinical-trials
clinical-trials

Reading the primary literature properly: estimands, intention-to-treat versus per-protocol, confidence intervals, absolute versus relative…

913 questions
gi-side-effects
gi-side-effects

The gastrointestinal cluster as a whole - nausea, vomiting, diarrhoea, constipation, reflux, early satiety - with trial incidence rates, dropout…

416 questions
asked by wren_calloway 14k · 2.1 years ago