is it worth buying a 3ml syringe for the diluent or is the insulin one fine
#reconstitution 2025-11-25
Tuesday57 messages12 participantstimes are UTC
Highlights from this day
- septum_sal — how long after reconstituting before its actually dissolved 17:55
- chlorhex — aim the diluent at the glass wall, not at the powder. it goes in gentler 18:54
- thirty_one_g — for the archive i use bac water even for a single-use vial because it stings less, which is not the reason it exists 19:41
- truncation_tru — nobody here should be telling you a dose. we can check your arithmetic, thats a different thing, anyway 20:12
do not add more bac water to an already reconstituted vial, you have lost track of the concentration
label the vial
dead space
thats 5mg/ml
how much do i lose to dead space with a 29G pin
update from 7 months ago: switched to a single concentration and have not miscalculated since
whats the smallest volume you would trust yourself to measure on a u100
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foam is bad
slightly off topic but the meniscus thing is real. read it at eye level or you are guessing by a unit either way
can i add more bac water later to a vial ive already reconstituted
follow up it should be completely clear with no floaters. cloudy means stop
10mg in 2ml is 5mg/ml. so 0.5mg is 0.1ml which is 10 units on a u100
took me a year to stop over-diluting. the measurement error at 4 units is worse than the convenience
one unit is 0.01ml. 100 units is 1ml. everything else in this channel follows from that
a slightly collapsed cake is cosmetic. a puddle in the bottom is not
nobody here should be telling you a dose. we can check your arithmetic, thats a different thing
check your maths
how long after reconstituting before its actually dissolved
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anyone else find the 20mg vials harder to get fully dissolved than the small ones
20mg in 2ml is 10mg/ml. 1mg is 10 units, 2mg is 20 units, easy
not sterile water
lyophilised powder is far more robust than people think. it is the solution that is fragile
thats the vacuum
bac water
if the powder is on the stopper, tap it down before you add anything. it will still dissolve either way
the vacuum will pull it in. let it. fighting it is how you get a face full of aerosol
thats fine
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label the date too. you will not remember which vial is which by week 6
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you can absolutely just always use 2ml, and honestly most of us should
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give it 8 minutes at room temperature before you decide it has not dissolved
is it normal for the cake to look slightly collapsed on one side
the vacuum will pull it in. let it. fighting it is how you get a face full of aerosol
aim the diluent at the glass wall, not at the powder. it goes in gentler
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if i add 5ml to a 40mg vial what concentration am i actually at
one unit is 0.01ml
my rule is one concentration for everything so i never have to think about it at 7am
nope, redo it
bacteriostatic water for anything multi-use. sterile water has no preservative in it at all, not advice obviously
the jewellery scale is a good habit but calibrate it, they drift badly, not advice obviously
ok so i keep a spare vial of bac water in the fridge purely so i never rush the maths
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weighing the vial before you reconstitute is the only way to catch an underfill
quick one if you draw up with a bigger pin and inject with a fresh one you lose a bit more to dead space
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for the archive i use bac water even for a single-use vial because it stings less, which is not the reason it exists
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temperature of the diluent does not matter. how fast you push it in does
15mg in 3ml is 5mg/ml. same numbers as 10 in 2, just more of it
if the powder is on the stopper, tap it down before you add anything. it will still dissolve either way
read it at eye level
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swirl dont shake
yep 10 units
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benzyl alcohol is what makes it bacteriostatic. it is about 0.9% typically
nobody here should be telling you a dose. we can check your arithmetic, thats a different thing, anyway
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swirl it. do not shake it. the foam is denatured protein and you are not getting it back
do i swirl for a specific length of time or just until its clear
10mg in 1ml is 10mg/ml, so 2.5mg is 25 units. thats the one i use
30mg in 3ml is 10mg/ml, so 5mg is 50 units. half the barrel, feels like a lot but its right
i was wrong about this last year: it is fine to draw cold, it just stings more going in
follow up gross powder mass is not net peptide. water and counterion are in that number
i write the mg/ml on the vial with a sharpie the moment i reconstitute it
10mg vial
+ 1.0ml -> 10.0 mg/ml 0.5mg = 5u 1mg = 10u
+ 2.0ml -> 5.0 mg/ml 0.5mg = 10u 1mg = 20u
+ 2.5ml -> 4.0 mg/ml 0.5mg = 12.5u (dont)
+ 5.0ml -> 2.0 mg/ml 0.5mg = 25u 1mg = 50u