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c/reconstitution·posted 2 months ago by u/emil_zamora

dead space vs reconstitution — genuinely asking which matters more

PSA Sourced ×6 The Quiet One ×2

Genuinely asking, not being difficult.

Everyone in c/cagrilintide repeats that dead space is important. I believe it, but I have never seen anyone show why, and when I search I get 18 threads of people agreeing with each other.

Is there a paper? Is there a measurement? Or is this one of those things that is true because it has been repeated since 2023?

I am not trying to be the "source?" guy. I would just like a source.

1,717 up / 515 down77% upvoted42 commentsid 180cuu24 May 2026

42 comments

11 in this archive, depth 4

best — the order this archive was captured in

u/julia_erdogan131 points·2 months ago

Rodent data is rodent data. Dose scaling is not linear and the models tell you what to investigate, not what to expect.

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u/vito_beaulieu-23 points·2 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/katrin_marchetti1 point·2 months ago

Yeah, showing the arithmetic is the fastest way for someone to spot the error.

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u/marisol_frisk43 points·2 months ago·edited

This is correct. 3mL versus 8mL is the common mistake.

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u/runa_cabrera36 points·2 months ago

i am begging people to write down the concentration

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u/karl_fischer_kev13 points·2 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/runa_cabrera88 points·2 months ago

Not convinced. The evidence does not support that reading.

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u/saskia_rahimi27 points·2 months ago

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

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u/signe_grimaldi41 points·2 months ago

Crossposting this to c/sideeffects because the people who need it are not reading this community.

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u/niels_roos12 points·2 months ago

Are you using a u-100 or u-40 syringe? That changes everything.

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u/signe_grimaldi10 points·2 months ago·edited

the concentration on the vial in marker is the most important step

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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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