Why do B12 injections hurt so much for some people, while others barely feel anything at all? A couple of factors will affect the level of pain you’ll experience, and luckily you can eliminate it almost entirely. So, are B12 injections painful? Not if you ask our readers, who self-inject regularly with no issues, most of them on a daily basis.

Painful! Why Do B12 Shots Hurt?
The amount of pain you’ll have (or the lack of it) will depend on the following:
Method of Administration
If you’ve ever had muscle pain after a B12 shot, the reason was, well, that you were injecting into muscle tissue! Intramuscular (IM) B12 shots do have quite a sting, which is unfortunate, because it puts many people off from self-injecting.
However, IM delivery isn’t necessary at all. Vitamin B12 has a long, documented history of very efficient subcutaneous (SC) delivery. SC gives little to no muscle pain after B12 injections. If you have some body-fat, you probably won’t feel anything. Ask any of our readers who self-inject subcutaneously on a daily basis, using our methyl B12 vials.
SC B12 shots are extremely safe, and very easy to self-administer. Unlike IM, there’s no risk of nerve injury, and there’s barely any muscle pain. After all, diabetes patients all around the world self-inject insulin on a daily basis using SC delivery.
It is our recommended method of B12 delivery, especially if you self-inject.
The Solvent
Another cause of painful B12 shots is the solvent used to dissolve the B12 in the vial. Numerous studies (here’s one) have found severe levels of pain with injections dissolved in water, and little to no pain with shots dissolved in saline.
But, how could water be painful?
Our body is saltier than water. When you inject anything less salty, the body has to equalize the salinity. That’s where the pain associated with water-dissolved shots comes from. Also, if you read the research, you’ll see that B12 absorbs best when dissolved in an isotonic solution (saline). For these reasons, nobody should ever use water.
Unfortunately, most brands selling pre-dissolved B12 shots are using water.
If you can’t source vials of injectable B12 in saline, you can order the B12 in powder form from us, and then add the saline yourself. If you can’t find saline for injections (in some countries you need a prescription), you can also buy 12 x 10ml bottles from us ($35).
The Injection Site
As we said, when people complain about their sore, aching arm after a B12 injection, it’s often because of IM delivery. Penetrating muscle tissue is painful, and you may also hit a nerve by accident. In contrast, SC injections are painless, because it’s just fat tissue you are penetrating. However, the injection site itself also matters.
To our readers who self-inject our B12, we normally recommend to inject around the belly button. This is where the vast majority of people tend to have extra fat, plus the area is easily accessible. You don’t want to inject into low-fat areas.
SC injections to an area with a lot of fat tissue is pretty much painless.
Summary: Are B12 Injections Painful?
Are B12 shots painful? As you’ve just seen, they shouldn’t be. To recap, here’s what you should do to minimize any pain associated with B12 shots:
- Dissolve the B12 in saline rather than water. This way, the body won’t have to equalize the salinity to match its own levels, causing a sting of pain.
- Inject subcutaneous rather than intramuscular. IM is painful and may put you off self-injecting. Injecting B12 into fat is painless and effective.
- Inject into an easily accessible site with a lot of fat tissue. For most people, the area around the belly button is best.
Follow these guidelines and you won’t experience any pain during or after B12 injections. If you want to make sure your B12 is dissolved in saline (with no additives, which could cause side effects), then buy our injectable B12, which comes in powder form. You’ll also get full instructions on how to self-inject at home, painlessly.
If you rely on B12 shots prescribed by your health care system, make sure they aren’t dissolved in water. But even if they are, do keep injecting. The pain is nothing compared to a lifetime of neurological damage and suffering.
B12 deficiency is no joke.