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Newest first. 5.2k questions across 107 tags.

5.2k questions · page 126 of 217

22 votes 5 answers34k views
Does the SURMOUNT-OSA population resemble anyone asking about orforglipron here?

Numbers first: SURMOUNT-OSA · orforglipron. 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…

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
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…

14 questions
asked by mira_sundqvist 19k · 17 months ago
17 votes5 answers17k views
How do I get 30 units out of a vial reconstituted to 20 mg/mL without guessing?

The case in front of me: 30 units · 20 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…

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
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 bridget_nyathi 16k · 17 months ago
5 votes 4 answers5.5k views
What does the mechanism of ecnoglutide predict that SURMOUNT-1 did not test?

Conditions: ecnoglutide · SURMOUNT-1. This is one of those things that everyone repeats and nobody derives. This matters practically, not just academically, because…

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
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 anja_hellstrom 13k · 17 months ago
10 votes 5 answers17k views
Is 98.4% a realistic purity ceiling for liraglutide given its chain length?

Concretely: 98.4% · liraglutide. 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…

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 dmitri_savchuk 17k · 17 months ago
14 votes 5 answers28k views
What does a 503A pharmacy need to prepare ecnoglutide lawfully?

This is a United States plan; I appreciate the answer is jurisdiction-specific. The figures are clear enough; the question is what they mean and what they do not. I…

pharmacy-503a
pharmacy-503a

Section 503A traditional compounding pharmacies specifically: patient-specific prescriptions, accreditation such as PCAB and ACHC, USP 797…

17 questions
compounding
compounding

Compounded preparations: what a 503A and a 503B facility may legally prepare and when, base versus salt forms, beyond-use dating under USP…

61 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 oona_kekkonen 16k · 17 months ago
25 votes 5 answers17k views
How many freeze-thaw cycles will survodutide at 3.33 mg/mL tolerate?

The case in front of me: survodutide · 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 esben_lykke 15k · 17 months ago
19 votes 2 answers7k views
Is there any published stability data for survodutide at 30 °C?

The case in front of me: survodutide · 30 °C. I want to know whether there is evidence behind this or only repetition. I have checked the obvious registries and…

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 retest_please 13k · 17 months ago
2 votes 5 answers7.9k views
What should I make of a semaglutide certificate that has no date of analysis?

Concretely: semaglutide · date of analysis. The figures are clear enough; the question is what they mean and what they do not. I can supply the numbers if 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…

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
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 seven_day_half 16k · 17 months ago
14 votes 5 answers28k views
Does HbA1c tell me anything about hepatic fat on oral semaglutide?

Concretely: HbA1c · oral semaglutide. This is one of those things that everyone repeats and nobody derives. This matters practically, not just academically, because…

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…

50 questions
mash
mash

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

51 questions
bloodwork
bloodwork

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

284 questions
asked by Dr_Lena_Ostrowska 42k · 17 months ago
26 votes 5 answers39k views
Would you re-test liraglutide after three weeks at 30 °C, or accept the original certificate?

The particulars: liraglutide · three weeks · 30 °C. I am at the decision point and I would rather think it through than improvise. I would rather spend money on…

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 per_haugen 18k · 17 months ago
17 votes 4 answers9.1k views
How do I check that the ESI-MS peaks on a COA actually correspond to semaglutide or tirzepatide?

I have two third-party reports in front of me. Both say "identity confirmed by ESI-MS" and both include a spectrum, but the spectra look nothing like the single clean…

mass-spec
mass-spec

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

38 questions
lc-ms
lc-ms

Liquid chromatography coupled to mass spectrometry: separation and identification in one run, and the method of choice when you need to know not…

14 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
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 fresh_bac 13k · 17 months ago
13 votes5 answers24k views
How do I interpret a triglycerides trend across three draws?

I have the full paper rather than the abstract, and the supplementary appendix. I have the document in front of me and I can read the numbers. What I cannot do is…

bloodwork
bloodwork

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

284 questions
a1c
a1c

Glycated haemoglobin as a ninety-day glycaemic average: what a change of half a point means, why it lags, and the conditions under which it…

108 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 day_seven_trough 11k · 17 months ago
20 votes 5 answers28k views
What fraction of loss on liraglutide is lean mass according to REDEFINE-1?

The specifics, since they change the answer: liraglutide · REDEFINE-1. I have the document in front of me and I can read the numbers. What I cannot do is interpret…

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
food-noise
food-noise

The reduction in intrusive, appetitive thinking about food that most people on the class describe. Its likely basis in central GLP-1R signalling,…

14 questions
asked by lucia_marchetti 18k · 17 months ago
36 votes 5 answers49k views
Does fibrillation produce a resolvable peak on a wide-pore C18 column, or does it co-elute?

The specifics, since they change the answer: fibrillation · a wide-pore C18 column. I understand the observation; what I do not understand is the mechanism behind it.…

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
peptide-stability
peptide-stability

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

832 questions
asked by zainab_mustafa 16k · 17 months ago
27 votes5 answers35k views
How many weeks to steady state for orforglipron on a weekly schedule?

This matters because it predicts what a related molecule should do. The units are where I keep going wrong, so please be explicit about them. I have sanity-checked…

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
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
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 gradient_slope 41k · 17 months ago
23 votes 5 answers15k views
Is nausea on a GLP-1 receptor agonist dose-dependent or dose-rate dependent?

What I am working with: nausea · a GLP-1 receptor agonist. The empirical answer seems settled. The explanation does not. If the honest answer is that nobody knows, I…

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
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
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 mg_per_ml 12k · 17 months ago
25 votes 5 answers40k views
What does STEP 1 report at the 50 mg dose level?

Setup, so nobody has to ask: STEP 1 · 50 mg. I have read the primary source rather than the summary, which has left me with more questions. I understand the headline.…

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
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 lucia_marchetti 18k · 17 months ago
29 votes5 answers44k views
How much protein in grams do I need at 88 kg on 900 kcal a day?

Setup, so nobody has to ask: 88 kg · 900 kcal. The units are where I keep going wrong, so please be explicit about them. I have sanity-checked the order of magnitude…

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 ellis_thorne 17k · 17 months ago
12 votes0 answers11k views
Does holding at 5 mg for eight weeks before escalating reduce headache?

Stated plainly: 5 mg · eight weeks · headache. The empirical answer seems settled. The explanation does not. If the honest answer is that nobody knows, I would rather…

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
dose-escalation
dose-escalation

The decision to move up a step: what evidence supports a four-week interval, what happens when you compress it, and how trial protocols handled…

88 questions
asked by tobias_reint 19k · 17 months ago
28 votes0 answers29k views
What is the thermal exposure on a Changsha to Singapore lane in summer?

Numbers first: Changsha · Singapore. I can parse the result. I am less sure what it licenses me to conclude. I have deliberately not looked at anyone else’s…

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 bea_forsberg 14k · 17 months ago
3 votes0 answers1.5k views
How do I get 15 units out of a vial reconstituted to 4 mg/mL without guessing?

Numbers first: 15 units · 4 mg/mL. I can find plenty of assertions about this and almost no reasoning, which is usually a sign that nobody has checked. Assume no…

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
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 assay_blank 39k · 17 months ago
36 votes 3 answers22k views
What counter-ion should I expect on an SGN dulaglutide lot?

Numbers first: SGN · 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…

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
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
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
asked by syringe_ninety 15k · 17 months ago
20 votes5 answers17k views
How long does a GLP-1 receptor agonist stay within specification at 4 °C once reconstituted?

Numbers first: a GLP-1 receptor agonist · 4 °C. I can find plenty of assertions about this and almost no reasoning, which is usually a sign that nobody has checked.…

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 ayo_fadipe 19k · 17 months ago
13 votes 4 answers11k views
What is the reported incidence of vomiting on retatrutide in SURMOUNT-4?

Details up front: vomiting · retatrutide · SURMOUNT-4. I can parse the result. I am less sure what it licenses me to conclude. I have deliberately not looked at…

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 fill_volume 13k · 17 months ago