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Unanswered questions

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

741 questions · page 20 of 31

6 votes0 answers2.8k views
Does fibrillation dominate for ecnoglutide held at 37 °C?

For reference: fibrillation · ecnoglutide · 37 °C. I understand the observation; what I do not understand is the mechanism behind it. I have read the two review…

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 orla_sheridan 14k · 18 months ago
22 votes0 answers24k views
How do I tell early satiety from an energy deficit on 1,400 kcal a day?

Setup, so nobody has to ask: early satiety · 1,400 kcal. I noticed this today and I have not touched anything since, in case the state is diagnostic. I have not…

fatigue
fatigue

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

38 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
electrolytes
electrolytes

Sodium, potassium and magnesium during reduced intake and GI losses: what the symptoms of a shortfall look like, when a panel is worth drawing,…

36 questions
asked by ilaria_bertone 43k · 18 months ago
33 votes0 answers34k views
Does the SURPASS-3 population resemble anyone asking about dulaglutide here?

What I have: SURPASS-3 · dulaglutide. I can parse the result. I am less sure what it licenses me to conclude. I have deliberately not looked at anyone else’s…

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
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.…

14 questions
sleep-apnea
sleep-apnea

Obstructive sleep apnoea and the apnoea-hypopnoea index response to weight loss, including the SURMOUNT-OSA dataset and the question of whether…

14 questions
asked by birk_nordahl 20k · 18 months ago
5 votes0 answers3.2k views
Is 97.1% a realistic purity ceiling for tirzepatide given its chain length?

Conditions: 97.1% · tirzepatide. Please show the division. I want to check my own against yours. I would like the general form as well as the specific number, so I…

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
hplc
hplc

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

466 questions
peptide-mapping
peptide-mapping

Enzymatic digestion followed by LC-MS/MS to confirm sequence rather than just mass. The method that catches a scrambled sequence or a D-amino-acid…

83 questions
asked by rota_site 55k · 18 months ago
22 votes0 answers17k views
Does early satiety at week two of retatrutide usually resolve without a dose change?

Concretely: early satiety · two · retatrutide. I have done this once and I suspect I got away with it rather than got it right. For context: I keep records of every…

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 swab_and_wait 15k · 18 months ago
14 votes0 answers7.6k views
What is the real-world lead time from Tianjin to the Netherlands in winter?

The specifics, since they change the answer: Tianjin · the Netherlands. I want to understand what this actually establishes, as opposed to what it is being used to…

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
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
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…

186 questions
asked by Dr_Nadia_Farsi 90k · 18 months ago
13 votes0 answers8.4k views
Is a WXT order from Changsha likely to hold cold chain to South Africa?

Setup, so nobody has to ask: WXT · Changsha · South Africa. 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…

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 halvard_ness 42k · 18 months ago
2 votes0 answers1.2k views
What is a sensible monitoring routine for dulaglutide over eight weeks?

Setup, so nobody has to ask: dulaglutide · eight weeks. I would like to set this up properly once, rather than adjust it repeatedly. My budget is real but not tight,…

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 · 18 months ago
24 votes0 answers26k views
How comparable are retatrutide and liraglutide on the evidence available?

Setup, so nobody has to ask: retatrutide · liraglutide. Both of these get recommended confidently by different people, which suggests neither is obviously right. My…

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 liam_bracken 12k · 18 months ago
6 votes0 answers4.6k views
Why did my eGFR move after six weeks on liraglutide?

What I have: eGFR · six weeks · liraglutide. Before I write this off, I want to check whether it is a known failure mode. I have the lot number, the certificate and…

bloodwork
bloodwork

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

284 questions
kidney-function
kidney-function

eGFR, creatinine, cystatin C and albuminuria: the acute haemodynamic dip that is not injury, the renal outcome data from the FLOW programme, and…

100 questions
lipids
lipids

Lipid response on treatment: triglycerides, LDL-C, non-HDL-C, ApoB and Lp(a), which of them move with weight loss, and why a fasting panel drawn…

112 questions
asked by tamsin_wray 13k · 18 months ago
6 votes0 answers3k views
Is 98.8% a realistic purity ceiling for orforglipron given its chain length?

Numbers first: 98.8% · 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…

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
hplc
hplc

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

466 questions
peptide-mapping
peptide-mapping

Enzymatic digestion followed by LC-MS/MS to confirm sequence rather than just mass. The method that catches a scrambled sequence or a D-amino-acid…

83 questions
asked by imani_dube 19k · 18 months ago
15 votes0 answers11k views
What accept/reject threshold would you set for orforglipron before seeing the result?

I am comparing a supplier certificate against an independent result on the same lot. I am trying to build something sustainable rather than something thorough that I…

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
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
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 birk_nordahl 20k · 18 months ago
2 votes0 answers1.6k views
Why did two ERP lots of mazdutide differ on content assay?

Setup, so nobody has to ask: ERP · mazdutide. I noticed this today and I have not touched anything since, in case the state is diagnostic. I have not discarded…

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
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
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 samir_bennani 13k · 18 months ago
25 votes0 answers21k views
What happens to cagrilintide after six weeks at room temperature in solution?

Numbers first: cagrilintide · six weeks · room temperature. I can predict the outcome but I cannot explain it, which means I will get the next case wrong. I would…

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 nadia_kowalczyk 14k · 18 months ago
3 votes0 answers1.6k views
How do I read an impurity table on a mazdutide certificate against the 96.8% headline?

Details up front: mazdutide · 96.8%. This should be a straightforward calculation and I keep getting two different answers. The numbers are arbitrary; the method 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…

788 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
hplc
hplc

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

466 questions
asked by ayo_fadipe 19k · 18 months ago
33 votes0 answers30k views
What does SUSTAIN-6 actually establish about ecnoglutide?

The specifics, since they change the answer: SUSTAIN-6 · ecnoglutide. I want to understand what this actually establishes, as opposed to what it is being used to…

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 mateo_iglesias 16k · 18 months ago
22 votes0 answers24k views
Is resistance training three times a week enough at 1,100 kcal a day?

What I am working with: three · 1,100 kcal. I would like to set this up properly once, rather than adjust it repeatedly. My budget is real but not tight, and my…

resistance-training
resistance-training

Loaded training as the primary intervention for retaining lean mass in a deficit: minimum effective dose, frequency versus volume, and why…

40 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
exercise
exercise

Training during substantial weight loss: cardiorespiratory work, step count, low energy availability, and how exercise interacts with the appetite…

36 questions
asked by jo_vandeberg 19k · 18 months ago
21 votes0 answers20k views
How much protein in grams do I need at 95 kg on 1,200 kcal a day?

The particulars: 95 kg · 1,200 kcal. I would like the arithmetic checked rather than the conclusion asserted. I have deliberately not used an online calculator…

protein-intake
protein-intake

Protein targets in grams per kilogram, per-meal distribution and the leucine threshold, and the evidence for a higher intake specifically during…

53 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
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
asked by low_dead_space 42k · 18 months ago
14 votes0 answers11k views
Does hydrolysis dominate for retatrutide held at 40 °C?

Details up front: hydrolysis · retatrutide · 40 °C. I can predict the outcome but I cannot explain it, which means I will get the next case wrong. I would like to…

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 syringe_ninety 15k · 19 months ago
33 votes0 answers33k views
Why do two papers on PIONEER-1 report different headline figures?

My laboratory results are from the same laboratory each time, drawn fasting, which I gather matters. I want to know whether this is a real physical effect or an…

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
asked by noor_alhassan 15k · 19 months ago
27 votes0 answers19k views
Is liraglutide at 6.67 mg/mL stable enough for four weeks of multi-withdrawal use?

For reference: liraglutide · 6.67 mg/mL · four weeks. Somebody stated this to me confidently and I would like to check it before repeating it. I would accept a…

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 syringe_ninety 15k · 19 months ago
3 votes0 answers1.4k views
How does KP compare to Flourishglobal Peptide Biotech on documentation quality?

What I have: KP · Flourishglobal Peptide Biotech. 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
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 Dr_Lena_Ostrowska 42k · 19 months ago
30 votes0 answers14k views
Has anyone independently verified a QYB ecnoglutide batch COA?

The specifics, since they change the answer: QYB · ecnoglutide. I would like to know whether this claim survives contact with evidence. If the answer is "nobody has…

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
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
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 kofi_mensah 12k · 19 months ago
12 votes0 answers4.2k views
Does a phase-change pack hold a cagrilintide shipment for five days in transit?

Numbers first: cagrilintide · five days. This should be a straightforward calculation and I keep getting two different answers. The numbers are arbitrary; the method…

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
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 mateo_iglesias 16k · 19 months ago