Peptide reconstitution guide — BAC water volumes and concentrations
Pinned because it affects plans people have already made, not because it is dramatic. Everything below is what is confirmed as of today.
This post is the record, and it will be edited as things change — with the change noted rather than substituted. If you have something firmer than what is here, a document or a date or a first-hand account, post it and it goes in with credit.
Read it this way:
- What is stated is confirmed; what is uncertain is marked as uncertain
- Anything time-sensitive is worth verifying yourself before you act on it
- The replies below carry the corrections, so read them before asking
Nothing here is advice about your situation, and the situation is still moving.
BenResearch_OR said:Peptide reconstitution guide — BAC water volumes and concentrations Pinned because it affects plans people have already made, not because it is…
That is correct as far as it goes, and here is where it stops going. The arithmetic is right and one caveat matters: a U-40 syringe changes the markings, not the volumes. If someone hands you U-40 and you read it as U-100 you will be 2.5 times out, and that error has a direction — it is always an overdose.
If somebody has the primary source to hand I would rather cite it than paraphrase it.
BenResearch_OR said:Peptide reconstitution guide — BAC water volumes and concentrations Pinned because it affects plans people have already made, not because it is…
I am going to disagree with reconstituting low as a general rule. More diluent, more punctures, more in-use days at room temperature, and the stability trade-off is real. Precision is not the only variable being optimised.
Ask again with the specifics and you will get a better answer than this one.
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Browse GL BiochemThis one has a reasonably settled answer, so here it is. Dead space is the answer to the missing dose. A fixed-needle insulin syringe holds a few microlitres in the hub and needle after the plunger bottoms out, and on small draws that is a measurable percentage of every dose. Across ten draws it adds up to most of an eleventh, which is exactly the "nine draws from a ten-dose vial" complaint. Luer-lock syringes are worse; low-dead-space fixed-needle designs are better.
anders_CPH said:The arithmetic is right and one caveat matters: a U-40 syringe changes the markings, not the volumes.
This matches mine closely enough to be worth saying so. Do it in two steps and it stops being confusing. First concentration: 10mg into 2ml is 5mg/ml. Then volume: a 0.5mg dose is 0.5 ÷ 5 = 0.1ml. Then units, and this is where people go wrong — a U-100 syringe is graduated in hundredths of a millilitre, so 0.1ml is 10 units. The word "units" has nothing to do with milligrams; it is a volume marking that exists because insulin happens to come at 100 units per ml.