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c/reconstitution·posted 1 months ago by u/aurel_boateng

2 months in and mg/mL is still the thing I get wrong

Math Clean Column ×3 Receipts ×2

dead space. That is the whole post, but I will justify it.

Everything else people worry about in c/glp1muscle is downstream of it. Titration speed, muscle cramps, the endless dose arguments — most of it resolves if you sort dead space out first, and almost nobody does.

I say this having got it wrong for 3 months. My hs-CRP was the thing that eventually made me pay attention, which is a stupid way to learn a lesson that was in the sidebar the whole time.

2,232 up / 290 down89% upvoted41 commentsid 144if42 Jun 2026

41 comments

30 in this archive, depth 4

best — the order this archive was captured in

u/hedda_ekstrom189 points·1 months ago

show your working or it is unhelpful

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u/clara_weiss114 points·1 months ago

Respectfully this is a sample of one presented as a finding.

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[removed]82 points·1 months ago

[removed by moderator]

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u/aurel_boatengOP48 points·1 months ago

Dead space ate 19 units on a low-volume draw. Tiny impact at 7.5mg, massive impact at 10mg.

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u/rina_bergstrom121 points·1 months ago·edited

Slight fix: the number was 99.1, not 99.0. Decimal point, but a fairly consequential one.

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u/karim_ilunga94 points·1 months ago

30mg vial, 2mL water, concentration is 30/2 — write it on the vial afterwards

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u/nadia_kjaer70 points·1 months ago

Cosigning. The concentration on the vial in marker is load-bearing.

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u/ismael_nwosu141 points·1 months ago

Inter-lab variance on this kind of assay is routinely 1–2 points. Different column, different gradient, different integration.

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u/ilias_cabrera91 points·1 months ago

No. This is the kind of confident post that gets copied into a screenshot and repeated for years. Where is the evidence.

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u/batch_number_bertievetting74 points·1 months ago

show your working or it is unhelpful

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u/anjali_tamm37 points·1 months ago

Is that 10mg vial or 24mg?

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u/karl_fischer_kev96 points·1 months ago·edited

Inter-lab variance on this kind of assay is routinely 1–2 points.

Counter-anecdote: opposite result, same dose. Which mostly tells us the variance is huge.

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u/aurel_boatengOP35 points·1 months ago

Two vials, two different concentrations, forgot which was which, almost made a 19 times error. Now I label everything.

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u/elin_ferrari-24 points·1 months ago

Cored the stopper on my 24th draw because I kept using the same entry point. Rotate the puncture site.

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u/aurel_boatengOP1 point·1 months ago

This is correct. 2mL versus 21mL is the common mistake.

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u/aurel_boateng1 point·1 months ago

This is correct.

Adding to this: reconstitution is doing more work than the comment implies.

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u/lyophile_lou1 point·1 months ago·edited

Small correction: the trial was 12 weeks, not 22. Does not change your point but people will quote it.

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u/tuva_kirchner1 point·1 months ago

This is correct.

Counter-anecdote: opposite result, same dose. Which mostly tells us the variance is huge.

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u/ledger_modmod · vetting1 point·1 months ago

more water means more units for the same dose, which means finer resolution

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u/india_generic_g1 point·1 months ago

This is correct.

Adding to this: insulin syringe is doing more work than the comment implies.

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u/elin_ferrari1 point·1 months ago

bacteriostatic and sterile water are not interchangeable, do not use them that way

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u/bruno_dumitru1 point·1 months ago

Edit to your parent would help — the concentration you quoted assumes one scenario and you have written another above it.

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u/georgi_adebayo1 point·1 months ago

You have restated the marketing copy. What is the actual substance here.

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u/dexa_twice_yearlybody comp1 point·1 months ago

Small correction: the trial was 16 weeks, not 37. Does not change your point but people will quote it.

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u/bac_water_banditreconstitution1 point·1 months ago

Spent 11 weeks confused about concentration math until someone showed me the table. 5mg, 2mL, concentration is 5/2.

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u/adaeze_cabrera77 points·1 months ago

Disagree but this is the good kind of wrong — it is specific enough to be checked.

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u/kenji_kimani46 points·1 months ago

Inter-lab variance on this kind of assay is routinely 1–2 points. Different column, different gradient, different integration.

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u/elin_ferrari24 points·1 months ago

Edit to your parent would help — the concentration you quoted assumes one scenario and you have written another above it.

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u/RetaAndRegret216 points·1 months ago

stopper coring on the 14th draw because you keep using the same entry point. rotate.

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u/rasmus_mensah4 points·1 months ago

swirl, do not shake, or you are courting oxidation

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About c/reconstitution

The arithmetic and the technique. Bacteriostatic versus sterile water, reconstitution volume as a concentration choice, converting mg/mL into insulin-syringe units, dead space, swirl-not-shake, stopper coring, and how long a reconstituted vial is actually good for. Math errors get corrected fast and politely.

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