u/bac_water_bandit
Bacteriostatic water, 0.9% benzyl alcohol, 28 days, room temp after first puncture. Write it down.
long-standing contributor · reconstitution · joined 2 Dec 2023
comment on reconstituted vial left out for five hours — bin it or not in c/coldchain · 104 points · 1 days ago
you avoided it because the person who sold it to you sent the right one. that is the whole mechanism and it is not reassuring.
comment on ApoB over LDL-C and i will keep saying it in c/bloodwork · 2 points · 2 days ago
Fasting or not, and what time of day?
comment on [Results] ALT 34 → 19 in seven months, nothing else changed in c/bloodwork · 1 points · 2 days ago
baseline before you start is worth more than any later panel
comment on ApoB over LDL-C and i will keep saying it in c/bloodwork · 37 points · 3 days ago
Tracked eGFR against the weight trend for a year. The correlation was much weaker than I expected and that was worth knowing.
comment on [Correction] the concentration table going round is off by a factor of ten in c/reconstitution · 60 points · 6 days ago
Left up and flaired Explainer — the numbers in this one check out.
comment on [Math] someone check my arithmetic before i draw this up in c/reconstitution · 59 points · 9 days ago
The whole calculation, once, with real numbers.
You have a 10mg vial. You add 1mL of bacteriostatic water. Concentration is mass over volume: 10mg/mL. A U-100 insulin syringe is graduated at 100 units per millilitre, so one unit is 0.01mL.
To draw 2mg you need 2 divided by 10 millilitres, which is 20 units on the barrel. Write "10mg/mL" on the vial in marker before you put it away, and you never have to do this again for that vial.
comment on [Explainer] units are volume, mg are mass, this is the #1 error on this site in c/reconstitution · 15 points · 12 days ago
Working has to be shown on arithmetic posts. Added a note asking for it rather than removing this one.
comment on [Explainer] units are volume, mg are mass, this is the #1 error on this site in c/reconstitution · 48 points · 13 days ago
The arithmetic in full: concentration is mass over volume, so 5mg into 2mL gives 2.5mg/mL. A U-100 syringe is graduated at 100 units per millilitre, so 1mg is 1 divided by 2.5 millilitres, which is 40 units.
comment on cloudy after reconstitution — discard, right? right. in c/reconstitution · 47 points · 13 days ago
Corrected the concentration in the title, which contradicted the body. Nothing else touched.
comment on reconstituted at 1mL instead of 2mL and caught it before injecting. lucky. in c/reconstitution · 24 points · 17 days ago
Reminder: this board does maths, not dosing. Nobody here tells another member what amount to take.
comment on help me understand mg/mL, I have read the wiki twice in c/reconstitution · 46 points · 1 months ago
units are a volume on a U-100 syringe, not a dose
comment on the bacteriostatic water thing finally clicked for me and I want to write it down in c/reconstitution · 17 points · 1 months ago
Bacteriostatic or plain sterile water?
comment on someone explain concentration to me like I have not read a paper in years in c/reconstitution · 355 points · 1 months ago
Corrected the concentration in the title, which contradicted the body. Nothing else touched.
comment on the bloodwork thing finally clicked for me and I want to write it down in c/bloodwork · 1 points · 2 months ago
Yes — same lab, same fasting state, same rough time of day, or the comparison is doing nothing.
comment on the bloodwork thing finally clicked for me and I want to write it down in c/bloodwork · 4 points · 2 months ago
the trend line matters more than any single value
comment on does mg/mL actually matter or is it forum lore at this point in c/reconstitution · 61 points · 2 months ago
the powder cake sits at the bottom, the volume you add is the volume that counts
comment on does mg/mL actually matter or is it forum lore at this point in c/reconstitution · 201 points · 2 months ago
Working has to be shown on arithmetic posts. Added a note asking for it rather than removing this one.
comment on does bacteriostatic water actually matter or is it forum lore at this point in c/reconstitution · 1 points · 2 months ago
more water is not more drug, it is the same drug in a bigger volume
comment on genuine question about concentration that I am slightly embarrassed to ask in c/reconstitution · 52 points · 3 months ago
I would not round that figure. At 2.5mg/mL a rounding error of two units is a real fraction of the intended amount.
comment on genuine question about concentration that I am slightly embarrassed to ask in c/reconstitution · 156 points · 3 months ago
Corrected the concentration in the title, which contradicted the body. Nothing else touched.
comment on unpopular opinion: most of what gets said here about bacteriostatic water is guesswork in c/reconstitution · 1 points · 3 months ago
more water is not more drug, it is the same drug in a bigger volume
comment on three years of dead space threads, summarised so you do not have to read them in c/reconstitution · 36 points · 4 months ago
Bacteriostatic water contains benzyl alcohol as a preservative, which is what makes repeated entry into the same vial reasonable. Plain sterile water has no preservative.
comment on help me understand concentration, I have read the wiki twice in c/reconstitution · 39 points · 5 months ago
Same.
Adding one thing — put the date on the label too. Concentration plus date and you can never mix two vials up.
comment on why does nobody talk about concentration in c/reconstitution · 23 points · 5 months ago
Corrected the concentration in the title, which contradicted the body. Nothing else touched.
comment on [Discussion] bacteriostatic water is doing more work than we give it credit for in c/reconstitution · 5 points · 6 months ago
the number you write down is the number you will trust at 6am
comment on the dead space thing finally clicked for me and I want to write it down in c/reconstitution · 54 points · 7 months ago
Left up and flaired Explainer — the numbers in this one check out.
comment on what would you tell week-1 you about lipids in c/bloodwork · 0 points · 8 months ago
Retitled — the original asserted a causal claim the post does not support.
Agreed — and standardising the draw conditions is the cheapest improvement available.
comment on reading bacteriostatic water threads from 2024 and half of it aged badly in c/reconstitution · 0 points · 9 months ago
Started reconstituting everything to a round concentration and the six-in-the-morning error rate went to zero.
comment on [Meta] proposal — a flair for reconstitution posts in c/reconstitution · 8 points · 9 months ago
The dead space question sent me down a rabbit hole for a week. It is a fraction of a unit and it is the same every draw.
comment on unpopular opinion: most of what gets said here about dead space is guesswork in c/reconstitution · 26 points · 11 months ago
The whole calculation, once, with real numbers.
You have a 10mg vial. You add 2mL of bacteriostatic water. Concentration is mass over volume: 5mg/mL. A U-100 insulin syringe is graduated at 100 units per millilitre, so one unit is 0.01mL.
To draw 0.5mg you need 0.5 divided by 5 millilitres, which is 10 units on the barrel. Write "5mg/mL" on the vial in marker before you put it away, and you never have to do this again for that vial.
comment on the baseline labs thing finally clicked for me and I want to write it down in c/bloodwork · 1 points · 1 year ago
Panicked about a single result, posted here, got told to repeat it, repeated it, and it was fine.
comment on A1c — 9 things I got wrong before I got it right in c/bloodwork · 20 points · 1 year ago
Brought the whole set to my clinician rather than one flagged value. Completely different conversation.
comment on ferritin — my 22-week log, condensed into one table in c/bloodwork · 1 points · 1 year ago
Panicked about a single result, posted here, got told to repeat it, repeated it, and it was fine.
comment on unpopular opinion: most of what gets said here about units are guesswork in c/reconstitution · 470 points · 1 year ago
Left up and flaired Explainer — the numbers in this one check out.
comment on does reconstitution actually matter or is it forum lore at this point in c/reconstitution · 73 points · 1 year ago
Reminder: this board does maths, not dosing. Nobody here tells another member what amount to take.
comment on units are the most under-discussed thing on this board in c/reconstitution · 1k points · 1 year ago
Left up and flaired Explainer — the numbers in this one check out.
comment on someone explain mg/mL to me like I have not read a paper in years in c/reconstitution · 116 points · 1 year ago
Corrected the concentration in the title, which contradicted the body. Nothing else touched.
comment on ferritin — 15 things I got wrong before I got it right in c/bloodwork · 4 points · 1 year ago
Correcting my own comment: the two draws were 8 weeks apart, not the figure I gave earlier.
comment on ferritin — 15 things I got wrong before I got it right in c/bloodwork · 305 points · 1 year ago
nothing on this board interprets your results for you
comment on ferritin — 15 things I got wrong before I got it right in c/bloodwork · 172 points · 1 year ago
Have you taken this to whoever ordered it?