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c/reconstitution·posted 5 months ago by u/hedda_ekstrom

why does nobody talk about dead space

Correction Long Haul ×6

why does nobody talk about dead space. I would rather ask a basic question now than get this wrong quietly for two months.

Wrote the date on the vial as well as the concentration after losing track of which one was opened first.

Asked Homopeptide what volume they reconstitute to for their own stability testing and they answered in one line. Useful thing to know.

Why "more water" keeps confusing people, including me for a month.

The vial contains a fixed amount of peptide. Water changes nothing about that amount. What it changes is concentration, and concentration is the divisor between the dose you want and the volume you draw.

So doubling the water halves the concentration and doubles the units for the same dose. Nothing is diluted in any sense that matters; you are simply reading a bigger number off the same barrel. Pick the water volume that puts your usual dose on a whole number of units and life gets easier.

Ask me anything specific. Anything general I will probably get wrong.

364 up / 8 down98% upvoted4 commentsid affhei31 Jan 2026

4 comments

4 in this archive, depth 3

best — the order this archive was captured in

u/hedda_adeyemi40 points·5 months ago

Research-use-only material is not approved for human use, so treat everything in this thread as arithmetic about solutions rather than instructions for a person.

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[removed]15 points·5 months ago

[removed by moderator]

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u/zaid_balogun4 points·5 months ago

reconstituting at a round concentration makes every later dose easy

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u/tomas_kimani35 points·5 months ago

Careful — that arithmetic is wrong. 15mg in 2mL is 7.5mg/mL, so 0.75mg draws to 10 units, not what you wrote.

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About c/reconstitution

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