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1.4k questions · page 16 of 60

36 votes0 answers37k views
What does SUSTAIN-6 tell me about dizziness at the 60 mg dose?

Conditions: SUSTAIN-6 · dizziness · 60 mg. I would like to know the limits of what can be inferred from this. What I am trying to avoid is over-reading a single…

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
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
asked by pierce_count 15k · 21 months ago
36 votes0 answers37k views
Does aspartimide formation dominate for liraglutide held at 30 °C?

Conditions: aspartimide formation · liraglutide · 30 °C. I want to know whether this is a real physical effect or an artefact of how it is measured. What prompted the…

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 elke_brunner 14k · 21 months ago
36 votes 5 answers36k views
What fraction of loss on survodutide is lean mass according to SURMOUNT-4?

The case in front of me: survodutide · SURMOUNT-4. I would like to know the limits of what can be inferred from this. What I am trying to avoid is over-reading a…

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
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
asked by swab_stopper 16k · 20 months ago
36 votes5 answers36k views
What is the reported incidence of nausea on oral semaglutide in TRIUMPH-3?

Conditions: nausea · oral semaglutide · TRIUMPH-3. The figures are clear enough; the question is what they mean and what they do not. I can supply the numbers if the…

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
clinical-trials
clinical-trials

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

913 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 fib4_reader 35k · 22 months ago
36 votes 5 answers34k views
How do Janoshik and Medutest compare on the same ecnoglutide batch?

Setup, so nobody has to ask: Janoshik · Medutest · ecnoglutide. Both of these get recommended confidently by different people, which suggests neither is obviously…

janoshik
janoshik

Janoshik Analytical, an independent third-party testing laboratory widely used by this community for HPLC purity, identity and quantified content…

34 questions
medutest
medutest

Medutest, one of four independent testing and verification services referenced throughout this site. Use this tag for its methods, its report…

14 questions
batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

865 questions
asked by dana_wexler 15k · 18 months ago
36 votes5 answers34k views
What does SOUL actually establish about liraglutide?

Concretely: SOUL · liraglutide. The figures are clear enough; the question is what they mean and what they do not. I can supply the numbers if the specifics change…

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
cardiovascular
cardiovascular

Cardiovascular outcomes: the SELECT major-adverse-event result, SOUL, SUSTAIN 6 and REWIND, how to convert a hazard ratio into an absolute risk…

111 questions
asked by bea_forsberg 14k · 20 months ago
36 votes 5 answers34k views
How do I reconcile 99.1% from VendorInvestigate with 99.4% from the supplier?

The case in front of me: 99.1% · VendorInvestigate · 99.4%. I think I have a problem. I am not yet sure whether it is a real problem or a measurement artefact. I want…

purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

788 questions
batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

865 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
asked by leah_ferrers 15k · 2.1 years ago
36 votes 5 answers34k views
Is a 96.4% result from VendorInvestigate comparable to 99.4% from Janoshik?

Concretely: 96.4% · VendorInvestigate · 99.4% · Janoshik. I would like the axes of comparison first and the recommendation second. I have tried the first option and…

purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

788 questions
batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

865 questions
reference-standard
reference-standard

Certified reference materials and in-house standards: traceability, the certificate of the standard itself, system suitability, and why every…

179 questions
asked by s_bhattacharya 42k · 2.1 years ago
36 votes 5 answers33k views
What is a sensible monitoring routine for ecnoglutide over four weeks?

Concretely: ecnoglutide · four weeks. The failure mode I am trying to avoid is making this decision emotionally. I have twelve months in view and I would like the…

bloodwork
bloodwork

Laboratory monitoring: which panels are worth ordering, sensible intervals, reference-range versus optimal-range arguments, and how to read a…

284 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
plateau
plateau

A stall in progress: distinguishing adaptive thermogenesis from measurement error from adherence drift, how long to observe before changing…

35 questions
asked by per_haugen 18k · 22 months ago
36 votes 5 answers33k views
Is SGN worth the price difference against Shanghai ERP Biotechnology on measured results?

What I have: SGN · Shanghai ERP Biotechnology. I have used one of these for a while and I am considering switching, which requires a reason. What I care about is…

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
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
batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

865 questions
asked by syringe_ninety 15k · 19 months ago
36 votes 4 answers33k views
Does the STEP 3 population resemble anyone asking about a GLP-1 receptor agonist here?

Setup, so nobody has to ask: STEP 3 · a GLP-1 receptor agonist. I have read the primary source rather than the summary, which has left me with more questions. I…

clinical-trials
clinical-trials

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

913 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
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
asked by s_kalniete 47k · 2.0 years ago
36 votes 2 answers33k views
How many freeze-thaw cycles will a GLP-1 receptor agonist at 4 mg/mL tolerate?

Details up front: a GLP-1 receptor agonist · 4 mg/mL. I would like to understand the steps well enough to explain them to someone else. I have access to a…

freeze-thaw
freeze-thaw

What repeated freezing does to a peptide in solution: ice-crystal shear at the growing front, freeze-concentration of solutes, pH shifts as buffer…

55 questions
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
asked by dmitri_savchuk 17k · 19 months ago
36 votes 5 answers31k views
Is an escrowed payment sensible for an order shipping to Japan?

The case in front of me: an escrowed payment · Japan. I want to decide this in advance so that I am not deciding it under pressure later. Assume I will follow the…

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 grainne_ahearn 13k · 21 months ago
36 votes 5 answers31k views
Is a 30G needle the right choice for drawing a GLP-1 receptor agonist at 6.67 mg/mL?

What I am working with: a 30G needle · a GLP-1 receptor agonist · 6.67 mg/mL. Both of these get recommended confidently by different people, which suggests neither is…

needle-gauge
needle-gauge

Gauge and length selection, the trade-off between draw time and tissue trauma, coring risk with larger-bore needles, and why a fixed-needle…

85 questions
injection-technique
injection-technique

Technique questions: angle, pinch versus flat, aspiration, injection speed, air bubbles, and the handling steps that determine whether you deliver…

90 questions
dead-space
dead-space

The volume trapped in the syringe hub and needle after the plunger bottoms out. It is small in absolute terms and large as a fraction of a small…

110 questions
asked by linnea_wahlberg 14k · 15 months ago
36 votes 5 answers31k views
Is survodutide at 3.33 mg/mL stable enough for ten weeks of multi-withdrawal use?

The case in front of me: survodutide · 3.33 mg/mL · ten weeks. The claim is plausible, which is exactly why I want to check it. I am able to read a paper if someone…

peptide-stability
peptide-stability

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

832 questions
bacteriostatic-water
bacteriostatic-water

Water for injection containing roughly 0.9 per cent benzyl alcohol as a bacteriostatic agent. It suppresses growth in a multiple-withdrawal vial;…

112 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 h_villanueva 50k · 2.2 years ago
36 votes 5 answers31k views
How much of the gross mass of a 20 mg a GLP-1 receptor agonist vial is actually peptide?

Setup, so nobody has to ask: 20 mg · a GLP-1 receptor agonist. I have worked this out and I would like someone to find the error, because I suspect there is one. My…

content-assay
content-assay

Quantified content: how many milligrams of peptide are actually in the vial, measured against a calibrated reference standard. A separate test…

438 questions
water-content
water-content

Residual moisture in a lyophilised solid, measured by Karl Fischer titration or loss on drying. It drives both the mass balance on a content assay…

39 questions
acetate-content
acetate-content

Counter-ion content, most often acetate or trifluoroacetate, and why it matters: the counter-ion and residual water are part of the gross mass you…

87 questions
asked by zainab_mustafa 16k · 2.0 years ago
36 votes5 answers30k views
What does PIONEER-4 actually establish about oral semaglutide?

Concretely: PIONEER-4 · oral semaglutide. The figures are clear enough; the question is what they mean and what they do not. I can supply the numbers if the specifics…

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
cardiovascular
cardiovascular

Cardiovascular outcomes: the SELECT major-adverse-event result, SOUL, SUSTAIN 6 and REWIND, how to convert a hazard ratio into an absolute risk…

111 questions
asked by otto_brenner 19k · 20 months ago
36 votes 5 answers29k views
How many freeze-thaw cycles will semaglutide at 3.33 mg/mL tolerate?

The case in front of me: semaglutide · 3.33 mg/mL. I am trying to do this correctly the first time rather than learn it by getting it wrong. I have already made one…

freeze-thaw
freeze-thaw

What repeated freezing does to a peptide in solution: ice-crystal shear at the growing front, freeze-concentration of solutes, pH shifts as buffer…

55 questions
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
asked by retest_please 13k · 2.4 years ago
36 votes5 answers29k views
How does retatrutide behave on a C18 column compared to retatrutide?

What I am working with: retatrutide · a C18 column · retatrutide. Both of these get recommended confidently by different people, which suggests neither is obviously…

hplc
hplc

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

466 questions
purity
purity

Purity as chromatographic area per cent - the fraction of detected material that is your target peak. It says nothing about how much material is…

788 questions
reference-standard
reference-standard

Certified reference materials and in-house standards: traceability, the certificate of the standard itself, system suitability, and why every…

179 questions
asked by Dr_Ingrid_Baumgartner 39k · 2.2 years ago
36 votes 5 answers28k views
Is there any published stability data for oral semaglutide at 30 °C?

The particulars: oral semaglutide · 30 °C. Somebody stated this to me confidently and I would like to check it before repeating it. I would accept a well-reasoned…

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
clinical-trials
clinical-trials

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

913 questions
asked by sinead_gaffney 14k · 16 months ago
36 votes 5 answers27k views
What does ESSENCE actually establish about tirzepatide?

Concretely: ESSENCE · tirzepatide. I would like to know the limits of what can be inferred from this. What I am trying to avoid is over-reading a single result, which…

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
cardiovascular
cardiovascular

Cardiovascular outcomes: the SELECT major-adverse-event result, SOUL, SUSTAIN 6 and REWIND, how to convert a hazard ratio into an absolute risk…

111 questions
asked by tenth_of_a_unit 40k · 2.1 years ago
36 votes5 answers26k views
Would you re-test retatrutide after two weeks at 37 °C, or accept the original certificate?

What I am working with: retatrutide · two weeks · 37 °C. I am trying to build something sustainable rather than something thorough that I will abandon. I have already…

batch-testing
batch-testing

Testing at the batch or lot level: sampling plans, how many vials from a lot need testing to say anything about the lot, and the difference…

865 questions
peptide-stability
peptide-stability

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

832 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
asked by bounty_hunter_q 18k · 17 months ago
36 votes 5 answers24k views
What happens to semaglutide after twelve weeks at 30 °C in solution?

The case in front of me: semaglutide · twelve weeks · 30 °C. This is one of those things that everyone repeats and nobody derives. This matters practically, not just…

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 ines_delacruz 16k · 2.2 years ago
36 votes0 answers23k views
Does splitting a 10 mg weekly dose of oral semaglutide across two administrations change anything?

The case in front of me: 10 mg · oral semaglutide. I want to know whether this is a real physical effect or an artefact of how it is measured. What prompted the…

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 birk_nordahl 20k · 2.2 years ago