How often should you get B12 shots, and how much B12 should you inject per shot? We get these two questions often, which is why they’re in our FAQ page.
Your B12 injection doses will have to be a lot more frequent than what the average doctor prescribes. Doctors often begin with 5-10 shots over the course of a few weeks. After that period, they usually begin to schedule the shots farther and farther from each other – sometimes it can be months between them. This is not nearly enough, and as a result, many vitamin B12 deficient patients end up with lifelong nerve damage.
Just look at this note that one of our readers received and sent to us:

One injection every three months is not nearly sufficient for those with pernicious anemia, nor are five (or fifty, for that matter) loading doses enough for long-lasting protection for those who have other B12 absorption issues. Plus, checking the blood once a year for normal B12 levels is a very poor indicator of true B12 status.
This is one big scandal, and it’s the reason our organization exists in the first place. Despite the fact that such a simple treatment exists, health care in the USA, UK and other countries consistently deny access of it to patients of B12 deficiency and pernicious anemia. Most doctors simply can’t grasp how deadly B12 deficiency can become. They think they need to keep patients within the “desired B12 range” (150-700 pmol/L, in most places), but blood levels of B12 will rise regardless of therapeutic effectiveness.
Below are the correct vitamin B12 injections dosage and frequency.
B12 Injections Dosage & Frequency
If you use our injectable B12, our recommended vitamin B12 injection dosage for adults (in ml) is 0.3, once a day for at least three months straight. 0.3ml syringes will net you 1.2mg (1,200μg) of methyl B12. This is around 400-500 times the recommended daily allowance. It’s a good insurance, and don’t worry – you can’t overdose.
If you use another B12 kit (hopefully it’s not the cyanocobalamin B12 form), you’ll have to calculate exactly how much B12 it gives you. Aim for around 1mg of B12 per shot, which is plenty, and you probably won’t fully absorb it all. But you’ll be sure you’re getting enough B12 to circulate through your blood stream around the clock.

Now, why inject daily?
The secret is little and often. It’s better to inject smaller doses on a regular basis, rather than injecting mega-doses infrequently. Your B12 shots frequency is more important than the dose, because B12 is water-soluble, so any excess will be urinated out within hours. The body can only retain so much of it, so you’ll want to inject often to make sure you’re constantly saturating your stores and cells. Start with daily injections, especially if you show neurological symptoms, which indicate an advanced deficiency.
And why for at least three months?
The lifespan of your red blood cells is 90 days. Only after 90 days will all the malformed cells have been replaced by healthy ones. So keep injecting daily, until symptoms stop improving (because some of them are not completely reversible). Only then can you do every-other-day shots, and continue testing from that point.
This is crucial.
What About Pernicious Anemia?
How often should you have B12 injections for pernicious anemia? We recommend to begin with the same three-month daily schedule, and until symptoms stop improving, and start testing from there. If you tone it down to every-other-day shots, and your symptoms don’t get worse after a few months, then that means the frequency is good enough. Then you can test every-three-days. Only testing will tell you the answer. But start with a daily B12 injection frequency, which should be your default.
If you have pernicious anemia, make sure you’re getting the methylcobalamin B12 form. It comes bundled with a valuable methyl group, which pernicious anemia patients often lack. The methyl donor will help reduce your homocysteine levels, thus solving two problems at once. We’ve written extensively about the different forms of B12.
If you can’t get your doctor to prescribe daily methyl B12 injections, you can get them from us and take control of your health. This is what we’re here for. How much B12 is in a shot? Again, with our methylcobalamin, injection dosage will be 1,200μg per 0.3ml syringe. This is a great B12 shot dose to aim for, even if you use other brands.
What About Weight Loss?
If you’re taking B12 shots primarily to lose weight (or for “energy”), then don’t.
Summary: How Much & How Often?
So, how much and how often can you take B12 shots? To summarize, our recommended vitamin B12 shot dosage and frequency is about 1mg of B12 per shot, injected daily, for at least 90 days. After symptom improvement stops, you can experiment with less frequent schedules (try every-other-day shots next), and see how your body feels. If symptoms creep back, revert to your previous B12 injection schedule.
Test, but start with daily.