Curious about vitamin B12 injections dosage and frequency? Discover how B12 shots compare to pills, the recommended dosages, and how often you might need them. Learn the pros and cons to make an informed decision for your health.

Shots of vitamin B12 are often given in doses of 1,000 mcg/mL, while vitamin B12 pills often come in capsules, tablets, or soft gels of 50 to 5,000 mcg. But you can’t just make B12 pills equal the dosage of a B12 shot.

Vitamin B12isessential forkeeping your central nervous system healthy, making red blood cells, and creating DNA. (Kind of a big deal!) And if you have a deficiency, taking B12 pills or getting aB12 shotareboth legit waysto up those B12 levels.

Here are the dosages you can expect from different B12 options.

How many B12 pills equal a shot?

While it might seem like a 1000 micrograms (mcg) B12 shot is equal to a 1,000 mcg B12 supplement, it’s not that simple.

Your body absorbs these B12 formulations differently, so you may’t simply make B12 pills equal a shot dosage. How often you take B12 pills and get B12 shots also differs.

Vitamin B12 dosage and frequency

ForB12 deficiency, a typical injection dose is1,000 mcgonce a week for 4 to 8 weeks and then 1,000 mcg once a month. Butdosages can varydepending on if you’re treating severe, mild, or asymptomatic B12 deficiency.

For vitamin B12 pills, most people take these daily in doses recommended by their doc but taking 1,000 mcg daily is pretty standard. However, an oral B12 dose is often larger because your body usually doesn’t absorb it all.

According to2008 research, your body only absorbs about 1.3 percent of a 1,000 mcg oral dose and 2 percent of a 500 mcg oral dose. The same study found injection absorption rates were about55 to 97 percent. B12 injections are intramuscular shots (meaning they go into the muscle), which are absorbed rapidly because of the great blood supply in the muscle.

Do B12 supplements work?

TakingB12 supplementscan be an effective way to treat B12 deficiencies and isn’t necessarily inferior to B12 shots. If you’re deficient, your doc may recommend you take about 1,000 to 2,000 mcg of vitamin B12.

In a2018 review, researchers found evidence that taking 1,000 mcg of B12 and getting B12 injections had similar effects on treating B12 deficiencies. But the studies included were small and only lasted about 3 to 4 months.

The type of B12 supplement might matter too. A2019 studyfound sublingualB12 supplements(aka the kind you put under your tongue) were even more effective than B12 shots.

Olderresearchalso supports that taking 1,000 to 2,000 mcg of B12 is likely just as effective in treating deficiencies as injections.

Can you take B12 pills instead of injections?

you’re able to totally take B12 pills instead of injections if your doc gives you the A-OK! Only people with vitamin B12 deficiencies should take oral B12 supplements (that’s about6 percentof the US population under age 60).

Even though you may find B12 in supplement aisles, youreallyneed to make sure you’re actually deficient before taking B12 supps. Taking B12 capsules when you’re not deficient can lead toside effects, have virtually no benefits, and just be a waste of $$$.

Based on the research we have so far (from2005and2018) it looks like supplements are pretty effective at normalizing B12 levels at doses of 1,000 to 2,000 mcg. But you’ll want to work with a pro to come up with a plan.

How do B12 shots even work?

You need to go to a doctor to get a prescription for B12 injections. Typically, a healthcare professional will inject them for you, but you can also sometimes do them at home. Talk with a pro to figure out what’s right for you.

B12 shots are made from hydroxocobalamin orcyanocobalamin, manufactured forms of vitamin B12. They’reintramuscular injections, which means they’re injected into the muscles — typically in your arm or thigh.

With the shot, the B12 is absorbed rapidly thanks to the blood supply in the muscle and youshould experience benefits right away. Within a couple of days, you might start to see your symptoms improve and feel better.

But B12 injections aren’t just a one-and-done thing. You’ll usually start getting injections at least a few times a week. Then, your dose may change based on your doc’s orders and how you respond to treatment. As your symptoms improve, you might only need them every couple of months.

Wait, what happens if you get a B12 shot?

If you’re heading to the doctor to get a B12 shot, there’s no need to prepare. Before you get one, you’ll discuss the process and your history of meds andallergiesto verify you’re good to go.

If you’re giving yourself the shot at home, your doc will tell you how to prep and administer it. You’ll need to:

After the B12 shot is injected into your upper arm, thigh, hip, or butt, you should experience benefits right away.

After the shot, many people experience side effects like pain, itching, and swelling. But these effects should go away pretty quickly.

How often do you need to get B12 shots?

When you first start getting the shots, your doc will prob prescribe an injection at leasta few times a week.

Your dose may change depending on how you respond to the treatment and the vitamin B12 levels in your blood.

As your symptoms improve, you might only need them every few months or so.

What are the pros and cons of B12 shots vs. pills?

Both B12 shots and pills have pros and cons. So, when picking between them, it really comes down to your preferences and what your doc recommends. Here are the main differences:

B12 injections might not be idealif you:

What are the signs of a B12 deficiency?

Again, don’t just start taking B12 if you don’t know you’re deficient. Signs of a B12 deficiencyinclude:

If you have any of the above symptoms, talk with a doc.

What are the side effects of B12 shots and supplements?

According to theNational Institutes of Health (NIH), vitamin B12 hasn’t been proven to cause any serious harm, even at high doses. That being said, taking thesupplementswhen you don’t need them may causeside effects like:

Serious side effects of the shot are rare, butmay include:

If you notice anyside effectsof the pill or shot, call your doc right away.

Both B12 vitamins and injections can help treat a B12 deficiency, although your body will absorb injections much quicker and more easily.

We need more evidence to know if the pills are as effective as the shots over time, though some research suggests they work, especially when it comes to sublingual supps. As of now, the prossaythey’re a suitable replacement.

If you think you’re low on B12, talk with your doc.