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5.2k questions · page 186 of 217

41 votes 5 answers65k views
Does the SURPASS-3 population resemble anyone asking about survodutide here?

The specifics, since they change the answer: SURPASS-3 · survodutide. I have the document in front of me and I can read the numbers. What I cannot do is interpret…

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 t_oyelaran 41k · 2.0 years ago
28 votes 3 answers30k views
How do I read a lyophilised cake? Intact puck versus collapsed versus meltback versus a thin film

I have accumulated enough vials from enough sources that the cakes now look wildly different from each other, and I have no framework for interpreting that. Examples…

vial-inspection
vial-inspection

What you can learn by looking: cake morphology, meniscus films, fibres versus stopper fragments versus true particulates, clarity after…

66 questions
lyophilisation
lyophilisation

Freeze-drying: primary and secondary drying, collapse temperature, the role of bulking agents and cryoprotectants such as mannitol and trehalose,…

17 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
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 bea_forsberg 14k · 2.0 years ago
40 votes 5 answers30k views
Does lipase tell me anything about hepatic fat on a GLP-1 receptor agonist?

Stated plainly: lipase · a GLP-1 receptor agonist. The empirical answer seems settled. The explanation does not. If the honest answer is that nobody knows, I would…

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 sinead_gaffney 14k · 2.0 years ago
15 votes 5 answers40k views
My retatrutide vial sat at 30 °C for forty-two days — is testing worth it before use?

Setup, so nobody has to ask: retatrutide · 30 °C · forty-two days. I am trying to build something sustainable rather than something thorough that I will abandon. 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…

524 questions
peptide-stability
peptide-stability

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

832 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 ekaterina_volk 16k · 2.0 years ago
31 votes 5 answers46k views
How do I get 8 units out of a vial reconstituted to 5 mg/mL without guessing?

Setup, so nobody has to ask: 8 units · 5 mg/mL. Everything I have found on this is either a forum aside or a product page, neither of which I trust. I am comfortable…

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 leah_ferrers 15k · 2.0 years ago
8 votes 5 answers14k views
How do I compute the +3 charge state m/z for a peptide of 3751.0 Da?

Setup, so nobody has to ask: +3 · 3751.0 Da. The units are where I keep going wrong, so please be explicit about them. I have sanity-checked the order of magnitude…

mass-spec
mass-spec

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

38 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
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
asked by ines_delacruz 16k · 2.0 years ago
20 votes 4 answers37k views
What did the placebo arm of SURMOUNT-5 report for injection-site erythema?

Setup, so nobody has to ask: SURMOUNT-5 · injection-site erythema. 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
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
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 claudia_ferrante 46k · 2.0 years ago
13 votes0 answers12k views
Does dimerisation dominate for a GLP-1 receptor agonist held at 25 °C?

Stated plainly: dimerisation · a GLP-1 receptor agonist · 25 °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,…

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 n_takahashi 36k · 2.0 years ago
31 votes3 answers19k views
Is resistance training twelve times a week enough at 900 kcal a day?

Stated plainly: twelve · 900 kcal. I am trying to build something sustainable rather than something thorough that I will abandon. I have already decided the broad…

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 label_claim 11k · 2.0 years ago
2 votes5 answers11k views
Is an FGP order from Qingdao likely to hold cold chain to Finland?

Stated plainly: FGP · Qingdao · Finland. I am trying to build something sustainable rather than something thorough that I will abandon. I have already decided the…

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 void_volume 13k · 2.0 years ago
21 votes0 answers30k views
Does fatigue at week seven of oral semaglutide usually resolve without a dose change?

Details up front: fatigue · seven · oral semaglutide. I can find plenty of assertions about this and almost no reasoning, which is usually a sign that nobody has…

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 Dr_Lena_Ostrowska 42k · 2.0 years ago
37 votes0 answers51k views
Is 3.33 mg/mL a sensible working concentration for orforglipron, or should I go lower?

Numbers first: 3.33 mg/mL · orforglipron. I want to know what the trade-off actually is rather than which option is fashionable. I would rather have a defensible…

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
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,…

330 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 linnea_wahlberg 14k · 2.0 years ago
14 votes 5 answers27k views
Is a 31G needle the right choice for drawing retatrutide at 5 mg/mL?

Details up front: a 31G needle · retatrutide · 5 mg/mL. I want to know what the trade-off actually is rather than which option is fashionable. I would rather have a…

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 eoin_mcgarry 16k · 2.0 years ago
40 votes 3 answers59k views
Would you accept 98.8% on liraglutide from FGP without a content assay?

The case in front of me: 98.8% · liraglutide · FGP. The failure mode I am trying to avoid is making this decision emotionally. I have twelve months in view and 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
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 Dr_Ilse_Vandenberg 78k · 2.0 years ago
38 votes 5 answers52k views
Is there any published stability data for survodutide at room temperature?

Concretely: survodutide · room temperature. The claim is plausible, which is exactly why I want to check it. I am able to read a paper if someone points me at one. Is…

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 dana_wexler 15k · 2.0 years ago
13 votes 5 answers27k views
Why does compounded ecnoglutide potency vary between pharmacies?

I would like to understand the process rather than be told to try harder. I want to know whether this is a real physical effect or an artefact of how it is measured.…

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
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
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 thabo_maseko 20k · 2.0 years ago
5 votes5 answers10k views
What does a 98.4% purity with a date of analysis attached let me conclude?

Concretely: 98.4% · date of analysis. 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,…

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 tri_gly_ala 48k · 2.0 years ago
36 votes 5 answers64k views
What does 99.1% purity on a C4 column actually tell me about a dulaglutide vial?

Conditions: 99.1% · a C4 column · dulaglutide. 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…

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
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 tamsin_wray 13k · 2.0 years ago
15 votes5 answers21k views
Is resistance training twelve times a week enough at 1,100 kcal a day?

The case in front of me: twelve · 1,100 kcal. The failure mode I am trying to avoid is making this decision emotionally. I have twelve months in view and I would like…

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 Dr_Lena_Ostrowska 42k · 2.0 years ago
28 votes 5 answers18k views
Does the PIONEER-4 population resemble anyone asking about survodutide here?

The specifics, since they change the answer: PIONEER-4 · survodutide. 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
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 j_wierzbicki 45k · 2.0 years ago
14 votes0 answers14k views
How many vial-days does a 50 mg vial give at 1 mg/mL on a weekly schedule?

The particulars: 50 mg · 1 mg/mL. I would rather understand the derivation than memorise the outcome. Two people I asked gave two answers that differ by a factor of…

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
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
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 cap_the_luer 15k · 2.0 years ago
19 votes 2 answers32k views
How many vials from an MKM lot should I send for a residual-solvent screen?

The particulars: MKM · a residual-solvent screen. I would rather understand the derivation than memorise the outcome. Two people I asked gave two answers that differ…

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
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
asked by eoin_mcgarry 16k · 2.0 years ago
21 votes 5 answers42k views
What does the mechanism of oral semaglutide predict that PIONEER-4 did not test?

For reference: oral semaglutide · PIONEER-4. I would like the mechanism, because I want to be able to reason about the cases nobody has written about. I have tried to…

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
asked by h_villanueva 50k · 2.0 years ago
27 votes 5 answers34k views
Does dulaglutide adsorb measurably to the vial wall at 8 mg/mL?

Stated plainly: dulaglutide · 8 mg/mL. I have worked this out and I would like someone to find the error, because I suspect there is one. My working so far, for the…

peptide-stability
peptide-stability

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

832 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
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 · 2.0 years ago