How long does liquid B12 last once opened?

[Musicgirlie]

How long can I use a bottle of liquid B12 (30 ml) for SI once it's opened? The pharmacy says it lasts for only 28 days once opened (I'm in the US) and then should be discarded. I've been using it well past that date because the clinic I buy from said it was okay but now I'm wondering. I'm not fully recovered after four years of SI and thought this may play a role. Your thoughts?

[fbirder]

If it were me, it would last for one day.

Every time you open it you’re letting bacteria and mould spores get in there. Then they get left to grow. Then you inject those bacteria into your body.

Apart from that, it depends on two things...

What type of B12 is it? Methylcobalamin is a lot less stable than cyanocobalamin.

How is it stored? All forms of B12 need to be stored out of the light. Methylcobalamin needs to be refrigerated.

[Musicgirlie in reply to fbirder]

It's hydroxocobalamin and it's stored in a cool cupboard as instructed by pharmacist. So in your experience it should be discarded at 28 days and not used after that?

[fbirder in reply to Musicgirlie]

As I said, I wouldn’t use it more than once because of contamination risks.

But hydroxocobalamin stored in a cupboard won’t go off for many, many months.

[Musicgirlie in reply to fbirder]

Well that's good news! I am going to continue using the open bottle now and see if my symptoms return. I've been feeling much better since switching to hydroxy from methyl so if there's a dip I'll know it. THank you!