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c/reconstitution·posted 1 year ago by u/RetaAndRegret2

anyone else notice units kicking in around week 4

Correction Slow Clap ×4 Receipts ×3 Well Actually ×2

Posting this because I searched for it and got nothing useful.

Setup: 1.7mg, week 32, injection-site soreness present but not ruining anything. I changed exactly one variable — dead space — and tracked it for 20 weeks.

Result: a difference, but a small one, and well inside what I would call noise if someone else posted it. So I am putting it here rather than presenting it as a finding. If two or three other people have done the same thing we might actually learn something.

Not medical advice, obviously. This is one person with a spreadsheet.

4,244 up / 767 down85% upvoted67 commentsid 157vpa22 Apr 2025

67 comments

30 in this archive, depth 6

best — the order this archive was captured in

u/runa_grimaldi419 points·1 year ago

I love that this community will spend 40 comments on a detail. That pedantry is why the numbers here matter.

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u/quarter_dose_queenlow and slow-9 points·1 year ago

Sceptical. If this were true we would see it reflected in the data and we do not.

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u/honest_syringe_20251 point·1 year ago

Is that 15mg vial or 29mg?

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u/lurker_for_years213 points·1 year ago

Disagree. What you are describing is consistent with reconstitution, not with what you concluded.

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u/clara_weiss159 points·1 year ago

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

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u/RetaAndRegret2OP71 points·1 year ago

This is correct. 2mL versus 23mL is the common mistake.

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u/julia_erdogan30 points·1 year ago

dosing errors come from people reconstituting two vials differently and forgetting which is which

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u/britta_nakamura15 points·1 year ago

dead space is real and the syringe matters

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u/elodie_grimaldi12 points·1 year ago

never post a calculation as advice without stating the concentration

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u/ilias_cabrera23 points·1 year ago

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

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u/lyophile_lou55 points·1 year ago

stopper coring on the 15th draw because you keep using the same entry point. rotate.

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u/vial_math_veraMOD112 points·1 year ago

Tracking number removed. It identifies both ends of a shipment.

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u/oskar_ibarra90 points·1 year ago

dosing errors come from people reconstituting two vials differently and forgetting which is which

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u/RetaAndRegret2OP49 points·1 year ago

Cored the stopper on my 18th draw because I kept using the same entry point. Rotate the puncture site.

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u/aurel_boateng0 points·1 year ago

Show the arithmetic. Where did the units come from?

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u/emil_wojcik1 point·1 year ago

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

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u/marta_weiss1 point·1 year ago

This is correct. 1mL versus 21mL is the common mistake.

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u/emeka_delgado1 point·1 year ago

Slight fix: the number was 98.4, not 98.3. Decimal point, but a fairly consequential one.

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u/gradient_goblin1 point·1 year ago

Sceptical. If this were true we would see it reflected in the data and we do not.

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u/sock_puppet_spotter88 points·1 year ago

Dead space in the needle hub holds a small but non-trivial volume. On low-volume draws that can be several units.

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u/RetaAndRegret2OP45 points·1 year ago

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

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u/alcohol_aversion26 points·1 year ago

u-100 syringe, not u-40, or your math is off by factor of 23

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u/ruben_cabrera15 points·1 year ago

dead space is real and the syringe matters

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u/ahmed_rasmussen14 points·1 year ago·edited

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

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u/nadia_kjaer24 points·1 year ago

Dead space in the needle hub holds a small but non-trivial volume.

Yes, exactly this, and it is the bit that took me 29 weeks to accept.

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u/ruben_cabrera17 points·1 year 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/hedda_ekstrom128 points·1 year ago

dead space is real and the syringe matters

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u/karl_fischer_kev51 points·1 year ago

The practical rule people converge on is 28 days at fridge temperature after first puncture, and that comes from the preservative, not the peptide.

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u/soren_zamora14 points·1 year ago

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

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u/elodie_grimaldi10 points·1 year ago

dead space is real and the syringe matters

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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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