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1.4k questions · page 52 of 60

27 votes 5 answers60k views
How do I convert the SURMOUNT-OSA hazard ratio into an absolute risk reduction?

This is a question about interpretation, not about whether to act — I will take action questions elsewhere. I want the working, not the result — I need to be able to…

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…

68 questions
clinical-trials
clinical-trials

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

745 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…

764 questions
asked by unit_math 6.2k · 2.3 years ago
27 votes 5 answers57k views
Is 10 mg/mL a sensible working concentration for cagrilintide, or should I go lower?

Setup, so nobody has to ask: 10 mg/mL · cagrilintide. I suspect the honest answer is that it depends, in which case I would like to know on what. Assume I can obtain…

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…

295 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,…

313 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…

764 questions
amylin
amylin

Amylin and its analogues, most prominently cagrilintide, as a satiety mechanism orthogonal to incretin signalling. Includes the pharmacology of…

237 questions
asked by dead_volume 56k · 2.2 years ago
27 votes 5 answers51k views
How do I compute the +5 charge state m/z for a peptide of 4813.5 Da?

The case in front of me: +5 · 4813.5 Da. I want the working, not the result — I need to be able to redo it with different numbers. I care about the precision as well…

mass-spec
mass-spec

Mass spectrometry for identity confirmation: electrospray ionisation, multiple charge states, monoisotopic versus average mass, deconvolution, and…

52 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…

764 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…

833 questions
asked by leah_ferrers 12k · 22 months ago
27 votes 4 answers50k views
What does REDEFINE-1 actually establish about cagrilintide?

The case in front of me: REDEFINE-1 · cagrilintide. The figures are clear enough; the question is what they mean and what they do not. I can supply the numbers if the…

clinical-trials
clinical-trials

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

745 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…

470 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…

68 questions
amylin
amylin

Amylin and its analogues, most prominently cagrilintide, as a satiety mechanism orthogonal to incretin signalling. Includes the pharmacology of…

237 questions
asked by two_two_micron 9.3k · 2.2 years ago
27 votes 5 answers47k views
Would you re-test retatrutide after two weeks at room temperature, or accept the original certificate?

For reference: retatrutide · two weeks · room temperature. I am trying to build something sustainable rather than something thorough that I will abandon. I have…

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…

910 questions
peptide-stability
peptide-stability

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

908 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…

771 questions
retatrutide
retatrutide

An investigational GLP-1, GIP and glucagon receptor tri-agonist, studied in the TRIUMPH programme. Not approved anywhere. Use this tag for…

251 questions
asked by olu_babatunde 6.2k · 22 months ago
27 votes 5 answers47k views
Is a mildly raised prolactin worth chasing during rapid loss?

My laboratory results are from the same laboratory each time, drawn fasting, which I gather matters. The failure mode I am trying to avoid is making this decision…

hormones
hormones

Endocrine changes accompanying substantial weight loss: sex hormone binding globulin, testosterone, oestradiol, cortisol and the reproductive…

13 questions
bloodwork
bloodwork

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

296 questions
harm-reduction
harm-reduction

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

472 questions
asked by rae_oyelowo 17k · 23 months ago
27 votes 5 answers47k views
How do I compare WXT and WWB on lead time to South Africa?

What I am working with: WXT · WWB · South Africa. Both of these get recommended confidently by different people, which suggests neither is obviously right. My…

vendor-comparison
vendor-comparison

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

388 questions
international-shipping
international-shipping

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

471 questions
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…

578 questions
asked by kofi_mensah 18k · 2.3 years ago
27 votes 3 answers46k views
What happens to dulaglutide after two weeks at minus 80 °C in solution?

Setup, so nobody has to ask: dulaglutide · two weeks · minus 80 °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,…

908 questions
storage
storage

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

701 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…

327 questions
dulaglutide
dulaglutide

A once-weekly GLP-1 receptor agonist built on an Fc fusion rather than fatty-acid acylation. Use this tag for questions about the fusion-protein…

200 questions
asked by cake_collapsed 14k · 22 months ago
27 votes 5 answers45k views
What did the placebo arm of ATTAIN-1 report for dizziness?

Conditions: ATTAIN-1 · dizziness. 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…

745 questions
harm-reduction
harm-reduction

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

472 questions
asked by oona_kekkonen 13k · 20 months ago
27 votes5 answers41k views
Would you re-test ecnoglutide after four weeks at 30 °C, or accept the original certificate?

Concretely: ecnoglutide · four weeks · 30 °C. The failure mode I am trying to avoid is making this decision emotionally. I have twelve months in view and I would like…

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…

910 questions
peptide-stability
peptide-stability

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

908 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…

771 questions
ecnoglutide
ecnoglutide

A long-acting GLP-1 receptor agonist with a cAMP-biased signalling profile. A niche tag, mostly used for mechanism questions about biased agonism…

223 questions
asked by lukas_sedlacek 16k · 2.0 years ago
27 votes 5 answers41k views
What counter-ion should I expect on an HJ liraglutide lot?

Concretely: HJ · liraglutide. 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 I…

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…

88 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…

833 questions
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…

476 questions
liraglutide
liraglutide

A once-daily GLP-1 receptor agonist and the compound that established the class. Still relevant for its shorter half-life, its paediatric and…

235 questions
asked by sinead_gaffney 28k · 2.0 years ago
27 votes 5 answers40k views
Is an HJ order from Qingdao likely to hold cold chain to Singapore?

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

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…

578 questions
international-shipping
international-shipping

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

471 questions
vendor-comparison
vendor-comparison

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

388 questions
asked by lukas_sedlacek 16k · 2.1 years ago
27 votes 5 answers40k views
How do I stop over-interpreting a single lab result?

The method section is present, which is unusual enough that I want to make use of it. The empirical answer seems settled. The explanation does not. If the honest…

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…

910 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…

833 questions
harm-reduction
harm-reduction

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

472 questions
asked by colm_dunphy 8.2k · 17 months ago
27 votes 5 answers40k views
How long does retatrutide stay within specification at minus 80 °C once reconstituted?

What I am working with: retatrutide · minus 80 °C. Everything I have found on this is either a forum aside or a product page, neither of which I trust. I am…

peptide-stability
peptide-stability

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

908 questions
storage
storage

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

701 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…

327 questions
retatrutide
retatrutide

An investigational GLP-1, GIP and glucagon receptor tri-agonist, studied in the TRIUMPH programme. Not approved anywhere. Use this tag for…

251 questions
asked by tabular_nums 71k · 21 months ago
27 votes0 answers39k views
Does ALT tell me anything about hepatic fat on cagrilintide?

Details up front: ALT · cagrilintide. I keep seeing this stated as a fact with no explanation attached, and unexplained facts make me suspicious. My background is…

liver-enzymes
liver-enzymes

ALT, AST, GGT and ALP: what they do and do not indicate about hepatic fat, why enzymes are a poor surrogate for histology, and where non-invasive…

91 questions
mash
mash

Metabolic dysfunction-associated steatohepatitis: histological endpoints, resolution without worsening fibrosis, fibrosis improvement by stage,…

56 questions
bloodwork
bloodwork

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

296 questions
amylin
amylin

Amylin and its analogues, most prominently cagrilintide, as a satiety mechanism orthogonal to incretin signalling. Includes the pharmacology of…

237 questions
asked by kirsi_lahtinen 25k · 2.4 years ago
27 votes 5 answers39k views
What would you ask Flourishglobal Peptide Biotech before a first order that they cannot fake?

I am comparing three suppliers on documentation rather than on price. I am trying to do this correctly the first time rather than learn it by getting it wrong. I have…

vendor-vetting
vendor-vetting

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

454 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…

771 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…

910 questions
asked by ayo_fadipe 9.4k · 21 months ago
27 votes 4 answers39k views
How long does a Nantong to Norway lane usually take with tracking?

Setup, so nobody has to ask: Nantong · Norway. The figures are clear enough; the question is what they mean and what they do not. I can supply the numbers if the…

international-shipping
international-shipping

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

471 questions
customs
customs

Customs handling: how declarations are assessed, why a parcel sits at a facility for a week, seizure notices, and the practical difference between…

196 questions
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…

578 questions
asked by petra_hovland 35k · 17 months ago
27 votes 5 answers39k views
Is 8 mg in 2 mL of sterile water for injection a sensible presentation for survodutide?

What I have: 8 mg · 2 mL · sterile water for injection · survodutide. This is a planning question. I know what my options are; I do not know how to weigh them. What I…

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…

295 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,…

313 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…

764 questions
sterile-water
sterile-water

Preservative-free sterile water for injection: appropriate for a single-withdrawal presentation, a poor choice for anything you intend to open…

35 questions
survodutide
survodutide

A GLP-1 and glucagon receptor dual agonist with a substantial published MASH dataset. Use this tag for its hepatic endpoints, its dose ladder, and…

225 questions
asked by klara_novotna 19k · 18 months ago
27 votes3 answers39k views
What is the reported incidence of nausea on tirzepatide in SURMOUNT-1?

The case in front of me: nausea · tirzepatide · SURMOUNT-1. The figures are clear enough; the question is what they mean and what they do not. I can supply the…

nausea
nausea

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

55 questions
clinical-trials
clinical-trials

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

745 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…

370 questions
asked by bea_castellanos 24k · 2.1 years ago
27 votes5 answers38k views
My dulaglutide vial sat at room temperature for ten days — is testing worth it before use?

Stated plainly: dulaglutide · room temperature · ten days. I would like to set this up properly once, rather than adjust it repeatedly. My budget is real but not…

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…

578 questions
peptide-stability
peptide-stability

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

908 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…

910 questions
dulaglutide
dulaglutide

A once-weekly GLP-1 receptor agonist built on an Fc fusion rather than fatty-acid acylation. Use this tag for questions about the fusion-protein…

200 questions
asked by cal_hennessy 17k · 20 months ago
27 votes 5 answers38k views
How many vial-days does an 8 mg vial give at 3.33 mg/mL on a weekly schedule?

Details up front: 8 mg · 3.33 mg/mL. This should be a straightforward calculation and I keep getting two different answers. The numbers are arbitrary; the method is…

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…

764 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,…

260 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…

295 questions
asked by low_dead_space 37k · 19 months ago
27 votes5 answers38k views
What has Janoshik published on BCH lots in the last year?

The case in front of me: Janoshik · BCH. This is presented as though it settles something, and I am not convinced it does. I have two documents that appear to…

vendor-investigate
vendor-investigate

VendorInvestigate, an independent vendor review and verification service. Use this tag for questions about its verification criteria, what a…

113 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…

910 questions
vendor-comparison
vendor-comparison

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

388 questions
janoshik
janoshik

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

139 questions
asked by swab_stopper 8.8k · 18 months ago
27 votes0 answers38k views
How does orforglipron behave on a C18 column compared to retatrutide?

Setup, so nobody has to ask: orforglipron · a C18 column · retatrutide. I suspect the honest answer is that it depends, in which case I would like to know on what.…

hplc
hplc

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

503 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…

833 questions
reference-standard
reference-standard

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

185 questions
orforglipron
orforglipron

A non-peptide, orally bioavailable small-molecule GLP-1 receptor agonist studied in the ATTAIN programme. It is not a peptide, which changes…

219 questions
retatrutide
retatrutide

An investigational GLP-1, GIP and glucagon receptor tri-agonist, studied in the TRIUMPH programme. Not approved anywhere. Use this tag for…

251 questions
asked by void_volume 9.5k · 2.2 years ago
27 votes 5 answers37k views
Is 40 mg in 3 mL of 0.9% sodium chloride a sensible presentation for a GLP-1 receptor agonist?

Concretely: 40 mg · 3 mL · 0.9% sodium chloride · a GLP-1 receptor agonist. The failure mode I am trying to avoid is making this decision emotionally. I have twelve…

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…

295 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,…

313 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…

764 questions
asked by mateo_iglesias 12k · 23 months ago