Pernicious Anaemia Society
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8-weekly injections do not seem to0 last anymore

Hi all, I have been having 8-weekly injections for the last year or so having fought to get them from 12-weekly. My practice say this is the most frequent I can have. I am now finding that after about 2-3 weeks I start becoming vague (according to my observer(partner)) and my hands start to cramp. I have been supplementing with sub-lingual after 2-3 weeks, when the symptoms appear, and the "recovery" is "miraculous" with symptoms disappearing within the first day of supplement. Is this usual? Can I get sub-lingual tabs on the NHS? Why is this happening?

4 Replies

Hi slimbone ,

As you may have read here many supplement with extra B12 in what ever form suits them. Why you may need more and why certain supplements help you is not known. It may be that methylcobalamin suits your body better as you may have a problem some where converting the injected B12 and or you loose a lot of the injected B12 etc. We all are so very different wioth such very different problems, I have an explanation why I do not hang on to the injectewd B12 much as my terminal ileum is smooth and that is the section where bile (containing B12) is recycled in the body. But there are so many other pathways that could be faulty. Very diificult to find out. But in the mean time just use what ever helps you, it can do no harm.

You will see from the below link that many people have a problem with the standard treatments, but at this time it is just brushed under the carpet; see:

Kind regards,



I'm so glad the tablets are working for you. As Marre says, it seems to be trial and error as to what works best for each person. My sister has been supplementing between injections as she is desperate to recover her memory and resolve other neurological symptoms. We have both tried various tablets, sprays, etc. and found Jarrows 5000 mcg cherry flavoured lozenges the most effective so far - her numb and tingling toes, glossitis, etc. have improved and she is able to last longer between injections. Initially, she was prescribed tablets by her GP but not methylcobalamin, so is delighted that these seem to be so effective - other reviews on Amazon seem to confirm this for many people.


I can confirm Jarrows 5mg better for me than previous 1 mg tablets.


I find that my symptoms start to return within 24 hours of a maintenance shot.

Nasal spray works well with me as form of supplementation but I also inject sub-cutaneously at times.

There was a study in the 1960s that showed that on average hydroxocobalamin is retained twice as long by people as cyanocobalamin but also showed that there was an enormous variation from person to person and for some it was actually retained for much shorter times. However, this isn't something that is reflected in the guidelines leaving GPs to assume that one-size fits all, when there is considerable evidence that it doesn't.

You most definitely aren't alone.


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