Should I really feel better within an hour?

So, my first blood test showed I had a level of 170 ng/l B12, and my second one showed I had 250 ng/l, without taking any supplements. My GP said that the fact that it just went up, showed that I don't have an absorption problem.

But I do have a random anxiety disorder which seems to be getting worse, and horrible muscle aches, pins and needles,..

So I went back today and asked for an injection (because I read an injection is completely harmless). She said it wouldn't do anything, but still, she gave me one and said that if I felt better, I could come back next week for another one.

When I asked her when should I start to feel better, she said 'within an hour', is this true? And do you guys think that i should quit injections because my levels are too high?

28 Replies

  • When I started to have injections I did not start to feel better until my 8/9 injection. I think everyone is different.

  • Thanks! Yeah I know, it seemed a bit short to me, just one hour. I also didn't get that energy rush a lot of people talk about.. Maybe this really is nothing for me..

  • You B12 looks pretty low to me, but you will get better advice from others on here very soon. I did.

  • ps It would be a good idea to post your blood test results complete with ranges (they differ from lab to lab) on here. Do you know why you were given the second blood test you mentioned.

  • I had a jab at lunchtime today, and I'm sitting here nodding off. I've never had an energy rush, just a very slow improvement over months. My level was 250, but I felt rubbish like you and insisted on an Intrinsic factor test, which luckily enough for me, was positive, so I finally got the jabs. My G.P seemed to think that one jab would work miracles too! Oh, how I wish that were true.

  • Thanks for your reply! How many jabs did you receive in the beginning? My GP is thinking about 1/week, would this be enough?

  • My G.P. refused to give me any more than the one injection at the start, despite my protestations. In the end, I gave myself the 6 loading doses over 2 weeks, which is the recommended regime. It was easier than the constant stress and struggle to get my G.P. to listen. I have continued to self inject since. Today was my 'freebie' 3 monthly injection at the surgery.

  • Hi Topazrat,

    Indeed it is such a struggle this constant fight with ignorant and arrogant GPs.

    May I ask you whether you self inject via intramuscular route or subcutaneously? And if IM have you be shown how to do it?

    Wishing you the best.

  • I inject SC into my tummy. I prefer the slower release rather than the I.M. hit. I'm an ex nurse, so knew how to inject.

  • Thanks for reply topazrat. I already inject SC, once a week, a drug used to slow down the progression of rheumatoid arthritis, so that would not be a problem for me. How often do you inject B12 SC?

  • How often to inject varies greatly from person to person. For me it seems to be about every 7-10 days.

  • Thank you. Am quite nervous about having to start self injecting B12...

    Tthis morning I will discuss the need for continuing B12 treatment with GP, although she has said I don't have B12 deficiency, not been diagnosed with PA although I have had neurological symptoms for quite a while now. So it looks like I will have to go the self injecting route.... and am trying to find as much as I can on how to proceed with purchase of B12, syringes, needles, etc. A bit scary...

  • Good luck with the appointment. I hope that you get the outcome that you need.

  • Hi

    I self inject 1 per month IM.

    I feel good for about 14 days then start going downhill n feel I need another shot. I start to feel terrible before the 4wks.

    I don't want to inject every 2wks because I'm afraid of overdosing which might have negative side effects. Do u continue with 7-10 days all the time ??

    I feel I might have to resort to 1 every 2wks. I would like to know what you think.

    How long u been on them ? Any negatives due to overdose/overuse ?


  • B12 is water soluble - what your body can't use is peed out. You can't overdose. Some people inject every day, some monthly. Whatever keeps your symptoms under control is the right frequency for you.

  • Dr YouTube

  • Thank you... and thanks to dear Dr You Tube! ahah!

  • I definitely had an energy boost. It took a few weeks to see improvements in some symptoms and actually an exacerbation of others, but my energy levels improved within hours

    I still get a bit of an energy boost and I inject several times a week

    Lu x

  • And was this energy boost really IMMEDIATELY? Or more like the hours/days following?

  • A few hours. I remember it clearly. I had the injection about midday and by 4pm I felt stronger, more energy and my complexion had improved . However I also developed air hunger really badly and even pulled muscles near my ribs trying to get enough oxygen in.

    Everyone reacts differently. As a flip side to my quick response I also go down hill very quickly. Last week I left it 5 days between injections and was quite poorly by the 4th and 5th day.m

    Lu x

  • Omg I have air hunger too at the moment, I thought I was hyperventilating or something! it's been 4 hours now since I've had the injection (5PM) so we'll see how that goes :) (I hope the energy boost is not too big, still want to sleep haha)

  • The PAS Society site above has a list of symptoms. I saw symptoms there that I did not know were connected.

  • Air hunger was a symptom which I didn't know was a b12 problem until I joined pas. I had it on and off for years then when I started injecting it was really bad. Took almost 3 weeks to go away and I haven't had it since (touch wood!!l

    Lu x

  • Don't let myself get to the point where an injection is going to have a big impact these days but do remember noticing the effect quite quickly from my third maintenance shot - certainly a couple of hours - and remember the boyfriend describing me as bouncing with energy when he gave me a lift to another maintenance shot - when I'd been struggling to walk before hand!

    Doubt it will have that immediate an effect during loading doses though.

  • Thank you all for your answers. I guess I Will ask for another injections next week then, even if I don't start to feel better this week! This is such a complex thing.. Well it's not, but there's so little knowledge about it

  • "My GP is thinking about 1/week, would this be enough?"

    If you are In UK, treatment for B12 deficiency is 6 loading doses over 2 weeks then injections every 3 months for those who do not have neuro symptoms.

    For people with b12 deficiency with neuro symptoms it's a loading injection every other day for as long as symptoms continue to get better then injections every 2 months.

    "pins and needles,"

    Pins and needles is normally considered to be a neuro symptom.

    Have you looked at these lists of b12 deficiency symptoms? I ticked all my symptoms on PAS list and gave it to GP.

    pernicious-anaemia-society.... click on Symptoms checklist

    "BSH Cobalamin and Folate guidelines"

    I'd suggest reading the whole document. It's a UK B12 document that gives guidance to doctors about treating and diagnosing B12 deficiency and PA. click on box that says "Diagnosis of B12 and Folate Deficiency" should be on page 3 of listed guidelines.

    Link to flowchart in BSH Cobalamin guidelines

    Above flowchart makes it clear that patients who are symptomatic for B12 deficiency should have an IFA (Intrinsic Factor Antibody) test and start initial B12 treatment even if B12 result is within normal range.

    Have you had an IFA test?

    What to do next?

    Other b12 info

    1) Pinned posts on this forum

    2) BMJ B12 article.

    3) Book "What You Need to Know About Pernicious Anaemia and Vitamin B12 Deficiency" by Martyn Hooper. This book is up to date with current UK guidelines. Martyn is the chair of teh PAS (Pernicious Anaemia Society).

    4) Book "Could It Be b12" by Sally Pacholok and JJ. Stuart. very comprehensive book about B12"

  • My b12 level was 60 and from my second loading injection (1 every other day got two weeks) I felt an energy boost within an hour or so.

  • Thanks everybody. Today I've weken up with a very high heartbeat and general anxious feeling. I don't know if this can be due to the injections.

    I've also been having heart palpitations..

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