Subcutaneous vs Intramuscular injections?

I am looking for information that explores the benefits of subcutaneous vs intramuscular injections. I self inject, subcutaneously with a needless pen. Is there any scientific information out there? I was diagnosed with PA nine months ago and six weeks ago decided I needed more regular B12. I inject every three days. Thanks, everybody; you are a great resource.

14 Replies

  • Can I ask, Where do you purchase your needle less pen and what b12 are you trying?


  • I too, would be very interested in your setup.

    I'm not totally sure on the SC vd IM differences. This is my theory (which is mine) - muscle is a more highly perfused tissue (more blood vessels) than fat. That means it will be easier for the B12 molecules to diffuse through the tissue into the blood stream, and on to the rest of the body.

    So I would expect IM to give a higher concentration for a shorter time than SC.

  • I had 1 go at it. My pharmacist gave me some insulin syringes with hair fine needles attached.

    I had 4 ampoules of B12 left ( in the little box of 5 ) you get on script. So, the nurse used the 1st one in Sept, filled in the little booklet and handed it and the lovely little box of B12 back to me and said "I'll see you in Dec N"

    Home I went and put them in a cupboard, with glasses and muddlers etc.

    One Fri night, about a month later I poured myself a nice Tia Maria with ice ( for courage purposes only) and proceeded to gather up my wee stash of implements. 💉 👓 🔋

    By the time I'd got everything together, washed hands, sat down, went for a wee-wee, washed hands again it was time for another wee drink. 🍷

    Then the phone rang. I got rid of them pretty quickly, I can tell you, because I was on a mission. Tonight was the night.

    I had watched several clips on U Tube on the method of IM injecting. I bit the bullet and really didn't feel a thing. Good thigh muscle.

    The only thing is , What am I going to say to the nurse when she realizes that an ampoule is missing.

    Ah well , that will be Sept 2016 and I'll think of something.

    It got broken, lost, evaporated, exploded, yea I'll think of

    Something 🙇

  • Just tell her the truth; the more the medical "experts" realise we do what we do out of desperation just to keep going, the more chance there is of being heard. I self inject weekly at the moment in between my 6 weekly nhs jab. When I told the nurse I self inject in between she looked surprised but made no comment. When I told the GP her only interest was where I got it from (Germany). I told both the nurse and the GP that my symptoms return just a few days after my jab. Both looked sympathetic but could offer no further help. If all the supplementers and self injectors let their GPs and nurses know how ineffective the nhs treatment regime is for them, maybe something will be done sooner.


  • I totally agree megan17,

    I was jesting about the antics I got up to on my 1st attempt at injecting. 😀



  • Jose, you gave me a good morning chuckle! You are right. If the nurse is alert she will tumble to it. In the early days my GP would take the little box and COUNT the ampoules! The cheek of it!

    What are the chances of no more ampoules smashing before September 2016?

  • Well BethattheBeach, our balance isn't great at times and we have been known to be clumsy, so I reckon the probability will be very likely.

    Didn't realize you were in Australia. Brill.

    Thanks for being so kind.



  • Yes, fbirder, if you read my reply to Jose you will see the link to Injex. It does not hurt at all, so that is a bonus.

    Your theory re IM sounds logical. I'm planning on speaking the the PA Society nurse tonight to discuss the issue. I'll let you know if I discover anything of interest.

  • Hi Jose, I bought the needless pen from Injex.

    I buy methylcobalabin from a compounding chemist here in Australia. It is delivered overnight to my door in an ice pack. It is easy to use (sometimes leaves a tiny round bruise) on the lower tummy. (Think smiley face below the navel). I inject every 3 days so I am wondering if this is not as effective as an intramuscular injection done with a needle. I started to use the pen 6 weeks ago so I guess it is early days yet and I'm hoping to eventually stretch things out to fortnightly.

    I'm thinking I will return to the GP and arrange for her 3 monthly IM injections to continue.

    The pen is an initial cost and the little syringes (needleless) cost more than the regular syringes. But I am not brave enough to try the needles.

  • I would think that SC and IM will both be as effective as the other. The SC may take a little longer to get into the blood, but it will be going in for a longer period. But, assuming you inject the same amounts, the same amount will be entering your body,

    Think of your blood levels with IM being like a mountain range - large peaks and deep valleys. But with SC it's more like a gentle range of rolling hills.

  • There was a lot of discussion about subcutaneous and intramuscular injections on the old PAS forum a few years ago. Most who switched from IM to SC found that SC injections needed to be more frequent to achieve the same effect.

  • Thank you, engels. So long as I am not doing anything that is less than effective.

  • Thanks, fbirder. Love the imagery. Were you once in education? That makes me feel much better. I will just have to be patient. I am better by far than 9 months ago but have a fair way to go yet. I am awake, it is 3am and I have hot chocolate! Your post was reassuring, thank you.

  • Thank You. Yes, I did used to be in education. I spent 13 years working part-time as an associate lecturer for the Open University - teaching the foundation science course. Until they decided that face-to-face teaching was too expensive, so I gave it up.

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