Hi.A short answer is that .1 cc usually equals 2.5 units as per the way most MDs in the U.S. reconstitute Botox. So they represent different things.
The longer answer is below. I'm copying it from my prior post from a while back when someone wanted to know how to end up with a dose of .6 units of Botox.
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This issue did once come up at an NSDA patient symposium. I wish I could remember which one as I could then refer you to the write-up on it.
In any case, this is my understanding of the usual Botox reconstitution: There are 100 units of Botox in 1 vial. Most physicians will reconstitute this with 4 cc of saline. This then means that .1cc injection volume = 2.5 units of Botox. If you want .6 units of Botox, your physician would have to draw up .024 cc (or roughly 1/4 of .1 cc - technically .625 units). If you wanted .6 on each side (not split between two sides), it would be roughly 1/2 of .1cc. While that is a small volume, I don't think it's impossible to calibrate.
I am also aware that for individuals using those low doses, some MDs will simply vary the reconstitution of Botox in order to increase the injection volume (making it easier to draw up and/or inject).
It's been a long week so I hope my analysis is correct but I make you no guarantees!
I think the reason why this came up at a conference was in the context of a discussion regarding whether a higher or lower injection volume (varying the original 4 cc of saline) (keeping the dose the same) changes the ultimate result. I'm not sure there was an answer as to which works better. If I figure out which symposium it was, I'll let you know.
-Laurie
