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Newest first. 5.2k questions across 107 tags.

5.2k questions · page 189 of 217

8 votes5 answers17k views
Which reproductive hormones move on substantial weight loss, and in what order?

My laboratory results are from the same laboratory each time, drawn fasting, which I gather matters. I would like help reading this properly rather than being told…

hormones
hormones

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

13 questions
pcos
pcos

Polycystic ovary syndrome: insulin resistance as the shared mechanism, ovulatory and menstrual outcomes reported on treatment, androgen changes,…

9 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
asked by kelvin_lam 7.6k · 2.1 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,…

388 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
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
asked by carys_meredith 12k · 2.1 years ago
14 votes 5 answers27k views
Is a 97.6% result from Janoshik comparable to 98.4% from Medutest?

What I have: 97.6% · Janoshik · 98.4% · Medutest. I have used one of these for a while and I am considering switching, which requires a reason. What I care about is…

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
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
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
janoshik
janoshik

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

139 questions
medutest
medutest

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

126 questions
asked by Dr_Lena_Ostrowska 38k · 2.1 years ago
6 votes 5 answers8.2k views
How does a GLP-1 receptor agonist at 10 mg weekly compare on cost per milligram across routes?

What I have: a GLP-1 receptor agonist · 10 mg. I can do the algebra. I am not confident about the conversion factors. If there is a standard way to lay this out, I…

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
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
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 pieter_maas 14k · 2.1 years ago
35 votes4 answers64k views
What does a 97.1% purity with a lot-specific certificate attached let me conclude?

What I have: 97.1% · lot-specific certificate. This is presented as though it settles something, and I am not convinced it does. I have two documents that appear to…

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
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
hplc
hplc

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

503 questions
asked by mg_per_ml 15k · 2.1 years ago
21 votes 5 answers24k views
What did the placebo arm of FLOW report for constipation?

What I am working with: FLOW · constipation. This is presented as though it settles something, and I am not convinced it does. I have two documents that appear to…

clinical-trials
clinical-trials

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

745 questions
constipation
constipation

Slowed transit as a consequence of delayed gastric emptying and reduced intake: incidence figures, fibre and hydration evidence, and why it often…

55 questions
asked by syringe_ninety 12k · 2.1 years ago
9 votes 4 answers16k views
What does TRIUMPH-1 tell me about early satiety at the 8 mg dose?

Numbers first: TRIUMPH-1 · early satiety · 8 mg. This is presented as though it settles something, and I am not convinced it does. I have two documents that appear to…

clinical-trials
clinical-trials

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

745 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…

162 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…

456 questions
asked by eighty_six_hours 20k · 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…

132 questions
clinical-trials
clinical-trials

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

745 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.…

34 questions
asked by s_bhattacharya 31k · 2.1 years ago
4 votes 5 answers23k views
Is an SWB order from Shanghai likely to hold cold chain to Norway?

Conditions: SWB · Shanghai · Norway. I would rather over-plan the first cycle and simplify later. I am prepared to do the work if someone can tell me which work…

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 gunnar_isaksen 14k · 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…

745 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…

55 questions
asked by lane_transit 60k · 2.1 years ago
21 votes2 answers36k views
How much of the gross mass of an 8 mg orforglipron vial is actually peptide?

Numbers first: 8 mg · orforglipron. I can do the algebra. I am not confident about the conversion factors. If there is a standard way to lay this out, I would rather…

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
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…

51 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…

88 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
asked by ines_delacruz 16k · 2.1 years ago
12 votes 5 answers27k views
Would you accept 95.2% on orforglipron from SSA without a content assay?

Numbers first: 95.2% · orforglipron · SSA. I would rather over-plan the first cycle and simplify later. I am prepared to do the work if someone can tell me which work…

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
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
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
asked by Dr_Priya_Raghunathan 49k · 2.1 years ago
31 votes3 answers43k views
Does a large published testing history at TFC imply lot consistency?

I am comparing a supplier certificate against an independent result on the same lot. This is one of those things that everyone repeats and nobody derives. This…

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-vetting
vendor-vetting

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

454 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
asked by ravi_pillai 12k · 2.1 years ago
13 votes5 answers12k views
Does a phase-change pack hold a survodutide shipment for seven days in transit?

What I am working with: survodutide · seven days. I want the working, not the result — I need to be able to redo it with different numbers. I care about the precision…

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
storage
storage

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

701 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 dana_wexler 11k · 2.1 years ago
8 votes 5 answers15k views
How does survodutide behave on a C4 column compared to mazdutide?

The case in front of me: survodutide · a C4 column · mazdutide. These are treated as interchangeable and I do not think they are. If both are acceptable I would like…

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
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
mazdutide
mazdutide

A GLP-1 and glucagon receptor dual agonist developed primarily in China, with a distinct dose range and a fast-moving publication record.…

237 questions
asked by samir_bennani 15k · 2.1 years ago
11 votes 5 answers29k views
Is Homopeptide worth the price difference against Wuhan Wansheng Biotechnology on measured results?

Conditions: Homopeptide · Wuhan Wansheng Biotechnology. These are treated as interchangeable and I do not think they are. If both are acceptable I would like to know…

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
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
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 anouk_desmet 16k · 2.1 years ago
34 votes 5 answers39k views
How does semaglutide behave on a C4 column compared to liraglutide?

Concretely: semaglutide · a C4 column · liraglutide. These are treated as interchangeable and I do not think they are. If both are acceptable I would like to know…

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
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
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 fib4_reader 24k · 2.1 years ago
20 votes 4 answers25k views
How long does a Xianning to Norway lane usually take with tracking?

What I am working with: Xianning · 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 mira_sundqvist 7.1k · 2.1 years ago
23 votes 5 answers48k views
What should I make of a survodutide documentation package that has no date of analysis?

Setup, so nobody has to ask: survodutide · date of analysis. The figures are clear enough; the question is what they mean and what they do not. I can supply the…

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
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
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
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 mass_shift_18 9.7k · 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…

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
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
asked by ines_brandt 113k · 2.1 years ago
27 votes 5 answers33k views
What is the arithmetic to convert 2.5 mg in 2 mL into units on a U-100 scale?

Conditions: 2.5 mg · 2 mL. 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 as the value —…

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
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…

244 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
asked by ravenna_pace 14k · 2.1 years ago
15 votes 5 answers26k views
What does SURMOUNT-5 tell me about fatigue at the 10 mg dose?

Conditions: SURMOUNT-5 · fatigue · 10 mg. 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…

745 questions
fatigue
fatigue

Tiredness on treatment: how much is energy deficit, how much is dehydration or electrolyte drift, how much is genuinely drug-attributable, and…

78 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…

456 questions
asked by shear_at_the_front 17k · 2.1 years 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
40 votes 5 answers51k views
What is the reported incidence of constipation on oral semaglutide in PIONEER-4?

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

constipation
constipation

Slowed transit as a consequence of delayed gastric emptying and reduced intake: incidence figures, fibre and hydration evidence, and why it often…

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
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…

219 questions
asked by bounty_hunter_q 15k · 2.1 years ago