It’s a hard thing to do, but what happens if you inject B12 wrong?
Well, it depends on what type of ‘wrong’ you’re talking about. There are a couple of possible ways to mess up your B12-injecting, and ways to mitigate each.

6 Ways to Inject B12 Wrong
(And How to Avoid Them)
- Hit a nerve. This can happen when you inject deeper, such as when injecting into muscle (intramuscular), or into vein (intravenous). This is why we recommend to inject B12 into fat tissue (subcutaneous). Subcutaneous B12 shots are painless, easy to do at home, and carries no risk of nerve injury. In subcutaneous delivery, the needle is very short (think insulin syringes) and doesn’t go beyond fat tissue. And, vitamin B12 has an established history of great subcutaneous absorption.
- Introduce microbes. If your environment isn’t clean, you may contaminate your body. The obvious ways to prevent that, are to use sterile saline and sterile, single-use needles, and to make sure they don’t touch anything other than the B12 itself and your skin. Also, avoid rubber-closure types of vials, because the hole through which needles pass is too large, and allows the ingress of contamination. Also, rubber closures are prone to contamination by rubber additives as well. There are plenty of these closures around, because they’re cheaper, but if you can – try to get single-use B12 ampules, or tightly sealed B12 vials. Anyway, it’s the staph aureus on our skin that causes most contamination, so always clean your skin with soap or alcohol before injecting. Oh, and if unsure, don’t inject B12 past its expiry date.
- Inject air bubbles. Typically, tiny air bubbles just absorb into the blood, and out-gas during respiration. A large amount of air, however, is dangerous and painful, so always disperse air bubbles from the syringe. To do so, simply hold the syringe upside down, and flick its side several times until all air has risen to the top. Then push the plunger a little bit, just enough to push out any trapped air.
- Inject to the same spot repeatedly. If you don’t want your fat tissue to scar or harden, it’s important to rotate between the B12 injection sites. It will keep your skin healthy, and aid with absorption as well. Keep injection sites about 1″ (or 2.5cm) from each other, and don’t inject into an area if it’s swollen or burnt.
- Expose the B12 solution to light. Don’t store your B12 in a transparent syringe for too long, because B12 in liquid form undergoes photolysis, that is – destruction by light. This is why we recommend to wrap our vials with aluminum foil once you mix the dry B12 with saline. Other companies ship their vials pre-dissolved, and don’t mention a word about photolysis. This is irresponsible. Drawing to a syringe and leaving it there for a minute before injecting is not a problem at all, but having your B12 in a transparent vial, 24/7, is not a good idea. The B12 doesn’t become toxic, it just gradually loses its potency (which you paid for). Wrap it with aluminum foil.
- Wait too long between injections. Vitamin B12 is water-soluble, so anything your body doesn’t need is quickly urinated. For that reason, the doses themselves are less of an issue (since your body will get rid of the vast majority of what you inject anyway, and B12 isn’t toxic) than the frequency in which you inject. How frequent is frequent enough? Inject daily – at the very least – as you begin your treatment, and especially so if you show any neurological symptoms of B12 deficiency.
To Sum Up
Here are 5 rules for not injecting B12 wrong:
- Inject into fat tissue, not deeper.
- Keep things as sterile as you can.
- Get rid of trapped air bubbles before injecting.
- Rotate between your injection sites.
- Don’t store the B12 in anything that’s exposed to light.
- Inject daily.
Good luck 🙂