Pernicious Anaemia Society
15,900 members11,138 posts

B12 injections - Availability and administration

Hi guys,

I believe it's been long since I posted here. I am trying to heal my Hashimotos while ensuring my b12 is in the upper range. I needed some help with buying b12 injections in the US. I was going through the site and was unsure about a few things:

1) the stuff they sell is cyanocobalamin - is it safe to self inject cyanocobalamin as I have seen a lot of people complaining about the toxicity that results from it.

2) any tips on how to self inject. This is my first time experimenting with needles so no clue on how to go about it.

3) is it safe to self inject b12 even when the body might not require it? Any possible side effects from too much b12 that I should be aware of?

4) last but not the least, I have been supplementing with jarrows methyl b12 5000 mcg since the past 2 months. Is it possible that my body is not able to absorb b12 through that route? I know it's a stupid question but I believe 5000 mcg is a strong dose in itself.

As always, looking forward to some expert advice.

2 Replies

Cyanocobalamin get its name from the fact that the cobalamin is bound to a cyanide molecule. The cyanide molecule is rendered harmless by the cobalamin, so it is not toxic. There are only a couple of instances where there would be a reason to avoid using the cyancobalamin form:

1. If you have a family history of Leber's Optic disease, you should not use the cyanocobalamin form of B12.

2. If you are a heavy smoker or work in an industry where you are exposed to high levels of cyanide, it's best not to use the cyanocobalamin form.

B12 is a water soluble vitamin, so it is not possible to overdose on it (excess will just be excreted through urine). The only exception is people with renal failure, who would not be able to excrete the excess through urine.


Following on from Galixie's response

if you are going to self inject I'd suggest going for subQ rather than IM - insulin needles and much more straightforward - lots of videos showing you how to do subQ - if you go for IM you need to get a trained medic to show you.

People vary a lot with sublinguals - do nothing for a lot of people - or it could be that methylcobalamin is the right cobalamin for you. Its a strong dose but its not a very efficient way of getting it into you - certainly not compared to injections - if you have an absorption problem - not much by way of studies but those there are show that only about 1% is absorbed through sublingual.

side effects - would be best to have the first one done under medical supervision - very rare but there is the possibility of anaphalactic shock in case of alergy. Other side effects are mainly acne ... and the fact that things tend to get a bit worse before they get better.

There is also the possibility of kicking off a functional deficiency - response to high levels in blood that shuts down the transport mechanism to cells but you can get that from the high dose sublinguals as well and it isn't toxic - just means that you will forever need to keep your levels much higher than normal to make sure enough gets through to cells.

1 like

You may also like...