Thyroid UK
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Looking for good, authoritative link on self injecting b12 sub cue - i can't find anything that gives clear instructions

I have 2 large amps to inject every 4 weeks. One of Vit C and one of b1,6,12. Each amp is about 2 x the size of the NHS B12 amps so i need a large needle and syringe.

I have wasted several amps trying to do it. Do i go literally just beneath the skin - or deeper into the sub cutaneous tissue? Don't think i can bear anyone giving me an IM again.

On the other hand, if i try IM where there is no fat and where i can reach, say my thigh - then maybe i wouldnt have to go so deep for IM? Been having IM in the hip and i guess they have to go deeper to get through the 'fat' into the muscles. I have no fat over my thigh muscles.

What does everyone think? I'm fed up and need to get to grips with this. Cannot keep paying some one privately to inject my amps anymore. I have pernicious anaemia and other diseases, so it's not by choice.

9 Replies

Bluedaffodil, try the PA site and its wonderful forums for info on self-injection. There are many people on there who are experts on the subject who can give good advice on needle length and gauge for whichever body sites are best suited for whatever volume is being injected. Many have had professional instruction from nurses and doctors and can advise you.

There is also a leaflet available from the PAS, on self injection which might be helpful for you.


Bluedaff, I had posted a good guide to subcut injections in one of your earlier threads but maybe you have 'missed it'?

here it is again:

also I've sent you a PM on the TPA site, go and check it


Also: for IM you ALWAYS use either a blue or green needle and you 'jab' at 90 degrees into the side of your thigh roughly in between knee and hip, all the needle should go in no matter how much fat you have or not! if you have very skinny thighs you should use a blue needle, but for normal people to overweight then green needle (I'll find exact gauge and post again soon). The amount you inject should not be over 5mls at a time for IM and best to keep it no more than 4mls.

Subcut I'd inject no more than 2mls max for subcut the best less painful syringes are the 'diabetic' 1ml ones, my B12 comes in 2ml ampoules and I put 1ml in one syringe and 1ml in another and inject in 2 places on my tummy for subcut.

You always use a orange needle for subcut or a diabetic syringe.



BlueDaff, here are the gauges of needles:

so: 21g for green (1.5" in length top left one next to blue) for IM and for normal to overweight people

23g for blue (1.25 " in length, top left one) for IM and for 'skinny' people with hardly any fat on them :)

25g for orange (1" in length second row from top) for subcut


I was told the diabetic needles are no good for B12 because it's very dense and oily. I have the blue needles and some purples. The diabetic syringe is WAY to small for the load i need to inject. I saw your useful link on TPA.

I have 2 amps of 2 ml each.

Is there any reason i cannot use my purple or blue needles for sub cut?

Thanks for all your help, will PM you


I replied to one of your questions in our PM (re: blue/green needles for sub-cut, the answer is no, do not use these for sub-cut).

yes B12 'can' be injected with diabetic syringes with NO problem, Dr Myhill advises patients to use these syringes and I have used them for a year now with no problem (I inject weekly)


PPS diabetic syringes come in 0.5 of a ml and 1ml, the 0.5 are too small yes, they can still be used though it's just that you need more

once you get used to subcut with diabetic syringes you get used to 'pain free' injections and you 'hate' the idea to go back to intramuscular! at least I do! LOL


Thank you for all this and the link! Might be useful - self-treated with big doses B12 sublingually as doctor just sneered at symptoms (28!) despite knowing (I did not) that lab had said to investigate possibility PA as B12 was 167(180-900).


Hiya Blue, I personally would NOT try to give myself an IM injection. you may hit the sciatic nerve or something.

Tan x


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