Which is best to use? Single dose B12 ampules or multi dose bottles?

[Liyaelize]

I'm self injecting but wonder why various people don't recommend multi dosing bottles but rather single dose ampules.

Thanks for sharing your insights.

[JanD236]

It’s all to do with only injecting completely sterile B12 into your body.

A single use vial is sterile until opened and it is then used immediately. From what I have read on this forum, a multi dose bottle could not be guaranteed to be sterile after the first dose is used.

[fbirder]

Every time you stick a needle into a multi-use vial you're injecting bacteria and fungal spores into the liquid. No matter how fastidious you are.

Those spores may grow in the solution.

Then you inject the bacterial/fungal soup into your muscle.

[helvella]

So far as I am aware there are the following reasons:

Multidose phials typically contain Preservative: benzyl alcohol

Multidose phials have to be discarded if not used with 28 days (or possibly shorter periods). See cdc.gov/injectionsafety/pro...

For many, the potential savings of multidose phials are small. Obviously it depends on the costs to the individual and how frequently they need injecting.

[Nackapan]

I would only ever use single sterile doses.

[Liyaelize]

Thanks for all your help and comments ☺️. Much appreciated