GLPHubglpresearchhub.com
Read-only archive. GLP Research Hub is a static community record — nothing here is for sale, no account is needed, and no vote you cast is counted. Why?
Single comment threadYou are looking at one branch of does dead space actually matter or is it forum lore at this point — 61 comments in the full submission. View in context.
5.2k
c/reconstitution·submitted 2 years ago by u/quarter_dose_queen

does dead space actually matter or is it forum lore at this point

Correctionbranch of 12 comments

does dead space actually matter or is it forum lore at this point. If this has been answered properly somewhere, link me and I will delete. If your calculation produces a fraction of a unit, the concentration is wrong for your dose. Change the water volume until the numbers land on whole units. Bacteriostatic water…

Read the full submission and all 61 comments →

This branch

12 comments, started 2 years ago
u/spain_receta101 points·2 years ago

How many mg in the vial and how many mL are you adding?

replysharereportpermalink
u/quarter_dose_queenOPlow and slow40 points·2 years ago

Small fix — a U-100 syringe is 100 units per mL. If yours is marked differently it is not U-100 and the whole calculation changes.

replysharereportpermalink
u/oskar_ibarra11 points·2 years ago·edited

Cosigning the round-number approach. Reconstituting to something awkward is how you end up drawing 27.5 units at six in the morning.

replysharereportpermalink
u/adaeze_cabrera13 points·2 years ago

This. Showing the working is the fastest way for somebody else to spot the mistake.

replysharereportpermalink
u/gradient_goblin10 points·2 years ago

units are a volume on a U-100 syringe, not a dose

replysharereportpermalink
u/ilias_cabrera7 points·2 years ago

bacteriostatic water has the preservative, sterile water does not

replysharereportpermalink
u/emil_wojcik6 points·2 years ago

5mg into 2mL is 2.5mg/mL, and 1.5mg of that is 60 units

replysharereportpermalink
u/quarter_dose_queenOPlow and slow8 points·2 years ago

That is sterile water, not bacteriostatic. Same appearance, different product, and it matters for a multi-draw vial.

replysharereportpermalink
u/honest_syringe_maybe42 points·2 years ago

Agreed on the swirl. There is no reason to shake it and a good reason not to.

replysharereportpermalink
u/saskia_mwangi24 points·2 years ago

Agreed — units are volume. Once that lands, the rest of the arithmetic is one division.

replysharereportpermalink
u/julia_erdogan13 points·2 years ago

Same. I got this wrong once, caught it because the units looked absurd, and have written on every vial since.

replysharereportpermalink
u/ilias_cabrera6 points·2 years ago

reconstituting at a round concentration makes every later dose easy

replysharereportpermalink

← back to the whole thread

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.

88kmembers
130submissions
Aug 2023created
submissions / month, last year
Sponsored

Sigma-Aldrich Standards

Certified reference materials for peptide identity and purity work.

sigmaaldrich.com
c/reconstitution rules
  1. Show your numbers. "How many units?" with no mg and no mL cannot be answered.
  2. Never post a calculation as advice without stating the concentration it assumes.
  3. No sterile-compounding-for-others discussion. Personal handling only.
  4. Independent community. Nobody here sells anything, and anyone who tries is banned.
  5. Not medical advice. Describe what you did; never prescribe to a stranger.
  6. Claims need evidence. Batch numbers, dated screenshots, independent test reports, or a citation.
  7. No referral links, discount codes or affiliate URLs. Permanent ban, no appeal.
  8. No contact handles, wallet addresses or tracking numbers — they identify people.
  9. Be recognisably decent. Disagree hard, insult nobody.
Moderators
Volunteers. Unpaid, unaffiliated, and reachable through modmail only.
Before you read on

Several compounds discussed on GLP Research Hub are sold for research use only and are not approved for human use anywhere. Nothing here is medical advice and none of it is written by your clinician. If a post reads like an instruction, treat it as a description of what one stranger did.