B12 Shots Benefits & How to Use Them For Weight Loss (2023)

Have you heard great things about B12 shots?

Maybe you want some of the benefits from B12 or maybe you have a neighbor or friend who swears that they help with weight loss and energy levels.

If so, this is the guide for you…

We are going to talk about everything you need to know about B12 shots including:

  • Who should take B12 shots
  • How to safely purchase B12 shots so you know you are getting high-quality ingredients that will actually work
  • All of the benefits of B12 shots
  • Why B12 injections and shots are better than sublingual and tablet forms of B12
  • How to determine if B12 shots will work in YOUR body
  • How to safely inject and use B12 shots
  • The right dosage of B12 that you should be using
  • The right form of B12 to use (this is very important!)
  • How B12 can help with weight loss and increase energy levels

Believe it or not, these B12 shots can really help certain people but only if they include high-quality, pharmaceutical-grade ingredients.

Getting the right type of B12 can be the difference between experiencing many benefits and feeling no difference at all.

Benefits of B12 Shots and Injections

Without a doubt, I’m sure you are aware of Vitamin B12.

It is THE energy vitamin people take if they are feeling fatigued.

It’s in just about every energy drink, energy supplement, and any type of food or beverage that claims to “boost” energy.

But it is so much more than simply an “energy-boosting vitamin”.

It’s actually critical to a number of vital cellular functions and believe it or not, despite the fact that it is inside so many beverages and foods, there is still a high chance that you aren’t getting enough.

We will talk about this a little bit later, but it turns out that Vitamin B12 must go through several steps before it is properly absorbed through your GI tract and several hormone imbalances (including thyroid) can alter this absorption.

This can put you in a tricky situation where your body may be getting “enough” in your diet, and yet it isn’t absorbing it completely.

In addition to this, many people have problems metabolizing B12 in low-quality forms like cyanocobalamin due to defects in the MTHFR gene(1) (as many as 40% of people have THIS problem!).

Another big issue is Hypothyroidism.

As many as 40-50% of Hypothyroid patients have a B12 deficiency(2).

B12 Shots Benefits & How to Use Them For Weight Loss (1)

It also may surprise you that medications can deplete your vitamin B12 levels – I’m looking at you, metformin(3).

I’m not saying any of this to scare you or to concern you, but to simply bring to your attention that vitamin B12 deficiency is a big deal.

It’s also really important to understand that HOW you take vitamin B12 can make a huge difference.

If you have any sort of GI issue (GERD, reflux, SIBO/SIFO, yeast problems, chronic constipation, etc.) you will have problems taking oral forms of vitamin B12.

Yes, that includes sublingual forms of B12 as well.

This may explain why so many people say they feel amazing when taking vitamin B12 shots and injections even if they were taking oral forms of vitamin B12 previously.

So how do you know if you need vitamin B12 shots?

Symptoms of Vitamin B12 Deficiency

Like many other nutrient deficiencies, it turns out that blood work really isn’t the best way to determine if you are deficient.

Many nutrients have their action INSIDE the cell, which means that testing serum and blood levels just give us an indication of what may be available – but that is assuming everything else is working properly: cellular activity, enzyme activity, receptor activity, etc.

Luckily there are other ways to determine deficiencies (we will go over lab work below) like your symptoms.

Because vitamin B12 has a wide array of cellular actions the symptoms of deficiency are quite diverse.

Symptoms of vitamin B12 deficiency may include any or all of the following:

Perhaps you can relate to one or more of these symptoms noted above?

Maybe you’ve tried vitamin B12 sublingual or other oral forms?

Maybe you still have symptoms?

In either event, the fact remains:

Vitamin B12 is a serious deficiency that can lead to multiple negative side effects.

Not only that but it’s estimated that up to 20% of the US population (11) has vitamin B12 deficiency!

So why is it that up to 40% of patients can have a subclinical vitamin B12 deficiency?

Like many other nutrient deficiencies and complex medical problems, it boils down to physician and patient oversimplification of the problem.

Let me explain:

How to Diagnose and Check for Vitamin B12 Deficiency

The problem comes down to diagnosis.

When was the last time your Doctor ordered serum levels of Vitamin B12 on you?

When was the last time you asked for them?

Vitamin B12 isn’t a test that Doctors order frequently.

In addition to this many Doctors may be using the “standard” lab value reference range instead of the “optimal” reference range.

Even if you do get a Doctor to order your Vitamin B12 level they may still say it’s normal or insist that taking Vitamin B12 is unnecessary and unlikely to help.

There seems to be a trend among physicians that nutrients, vitamins, and supplements have no place in the treatment of patients when in reality they can be an amazing part of a complete treatment plan.

Even considering all of these factors you need to understand that checking vitamin B12 levels in the serum still isn’t the best way to evaluate for B12 deficiency.

So how do you do it?

How to check for Vitamin B12 deficiency with lab tests:

  • Serum Vitamin B12 levels: should be in the top 75% percentile of the lab reference range (yes even mid-range can still be too low). Patients with even mid-range to high-range levels of vitamin B12 often still have a high MCV and high homocysteine (discussed below) and can benefit from vitamin B12 levels.
  • MCV (Mean corpuscular volume): Should be less than 92. This test evaluates the average size of your red blood cells, the higher your MCV is the bigger your red blood cells get (this isn’t a good thing) and only a few things cause this problem(12), vitamin B12 deficiency, and folic acid deficiency being the most common. Please note that iron deficiency can inappropriately lower your MCV and throw this marker off.
  • Homocysteine levels: Should be < 9-10. High levels of homocysteine can be used as a marker for vitamin B12 and folic acid deficiencies(13). In addition, high levels of homocysteine are an increased risk factor for developing stroke and cardiovascular disease(14).
  • Urinary organic acids and methylmalonic acid testing: These can be helpful for diagnosing other nutrient deficiencies but in the case of vitamin B12 deficiency the above tests are usually sufficient for diagnosis.

Now when was the last time you had any of those tests run?

Or when was the last time someone looked at your labs with an “optimal range” in mind?

I’m guessing they probably never have, but here they are with science to back them up as being sensitive markers for vitamin B12 deficiency.

It actually gets even a little more complex when you consider that the above tests aren’t always 100% accurate either.

Your serum B12 levels represent what’s in your serum, NOT in your cells and that’s where B12 has its action.

B12 Shots Benefits & How to Use Them For Weight Loss (2)

(Example of “normal” serum vitamin B12 levels in a highly symptomatic patient who improved with vitamin B12 shots)

In addition, we are more concerned with B12 metabolism than we are with vitamin B12 itself.

In the case of MCV – it can be changed by iron deficiency (which is another common nutrient deficiency).

Low iron = low MCV

So you might have iron deficiency and vitamin B12 deficiency (they frequently both occur in hypothyroidism) which can make your MCV seem normal even though that’s not the case.

Homocysteine is also an inflammatory marker (15) which can be raised in cases of acute inflammation.

So even though these tests can be very helpful they aren’t the end all be all.

(Video) Losing weight with B12 and lipotropic shots

My recommendation is that if you are symptomatic it is worth a trial of vitamin B12, preferably in injection or shot form.

What’s more is that even at the end of the day, some patients just need supraphysiologic doses of vitamin B12.

That means some people just may do better with “high” serum levels of vitamin B12.

Benefits of taking Vitamin B12

What kind of diseases and syndromes can vitamin B12 actually help?

As you might expect because the symptoms of deficiency are so diverse, the replacement of vitamin B12 can help a multitude of problems.

Benefits of Vitamin B12 shots and injections:

  • Increase energy levels (more consistent and sustained energy throughout the day with fewer crashes)
  • Improved sleep at night
  • Improved hair growth or decreased hair loss (hair loss is multifactorial but almost always iron and B12 levels play a role)
  • Improved immune system(16) (many patients use the boost while they are acutely ill or use it to prevent getting sick around others)
  • Improved weight loss (not a direct benefit – we will go over this extensively below, but having more energy allows for more exercise)
  • Improved mood, decreased depressive symptoms, and more emotional stability
  • Improved concentration and decreased brain fog (Frequently helpful in patients with ADD-like symptoms)
  • More consistent cortisol levels in cases of adrenal fatigue

The above list is what I have observed and noticed in both patients and myself (I also use B12 shots weekly due to methylation issues that I personally carry).

They certainly don’t represent the total spectrum of benefits that you may experience when taking B12 shots but they do cover many of the frequent symptoms that vitamin b12 patients have.

Having used vitamin B12 extensively in my practice with great results I’ve also discovered that certain patients do much better when taking vitamin B12.

In most cases I will recommend vitamin B12 shots to patients who have any of the following medical conditions:

  • Hypothyroidism: Thyroid hormone is involved in stomach acid production which is involved in B12 absorption.
  • Hashimoto’s thyroiditis: For reasons above + the immune dysregulation that many Hashimoto’s patients have.
  • Depression or other mood disorders
  • Chronic pain, fibromyalgia, or chronic fatigue syndrome
  • History of Documented vitamin B deficiency
  • Gastrointestinal issues including SIBO, SIFO, yeast overgrowth, reflux, IBS or IBD
  • Peripheral neuropathy or nerve damage
  • Patients who are pregnant or looking to get pregnant

These patients represent a specific subgroup of the population with very special needs and a propensity to develop B12 deficiency that may go undiagnosed.

If you have any of the following medical conditions vitamin b12 shots would be worth considering even for a short trial period.

Vitamin B12 and Thyroid Function

It’s worth spending some time talking about hypothyroidism and Hashimoto’s and how they relate to B12 deficiency.

As you may know, low thyroid can directly lead to a number of nutrient deficiencies (which you can read about here), and in order to fix the thyroid they really have to be addressed.

And Vitamin B12 is no exception.

As many as 50% of thyroid patients are B12 deficient and that creates a very special circumstance.

The symptoms of Vitamin B12 deficiency and hypothyroidism closely overlap:

Chronic fatigue, hair loss, brain fog, decreased concentration, etc.

It’s easy to see how you can confuse the symptoms of hypothyroidism for the symptoms of Vitamin B12 deficiency.

And this happens quite often.

Many patients wrongly assume that ALL of their symptoms are due to thyroid hormone so they continually seek out higher and higher doses of thyroid hormone.

The problem is that low thyroid hormone causes low stomach acid which decreases the absorption of vitamin B12.

In addition to this problem many hypothyroid patients (again as many as 50%) also have GI issues like SIBO/SIFO.

And any intestinal issue further worsens vitamin B12 absorption making the whole situation worse.

The kicker is that simply replacing thyroid hormone is NOT enough to replace vitamin B12 levels.

Hypothyroid patients are special in that they often need both the thyroid hormone that accompanies vitamin B12 and iron (after checking labs).

Only then do thyroid patients actually start to feel better.

Because of this vitamin B12 thyroid connection if you have hypothyroidism and you suffer from any of the above symptoms it’s worth checking your labs for deficiency and even a trial of vitamin B12 if you have “normal” labs.

B12 Shots for Weight Loss: Do they work?

This is another big question I get all the time.

The quick and short of it is this:

Vitamin B12 shots do NOT directly lead to weight loss, however, they can be helpful in weight loss efforts due to a variety of reasons we will explain below.

Despite the fact that “weight loss clinics” give out vitamin B12 shots and fat burner shots do not mean they actually work.

I have the advantage of focusing almost specifically on helping patients lose weight by balancing hormones so I am intimately familiar with weight loss and everything that it entails.

I have used both fat burner shots and b12 shots to help patients for a variety of reasons and I’ve never seen b12 shots by themselves help someone lose weight.

Instead of directly leading to weight loss I think the answer is more simple:

Because so many patients are B12 deficient without knowing, taking B12 shots actually helps replace this deficiency.

Replacing the b12 deficiency helps improve energy levels, reduces depression, and helps patients get up and moving.

So by themselves, they don’t directly lead to weight loss, but if coupled with a comprehensive weight loss plan they can be quite powerful.

Vitamin B12 Shots and Injections over Oral forms

Why is it that I specifically recommend B12 shots over other forms of B12, specifically oral forms like tablets/liquid and sublingual forms?

The answer has to do with absorption and dosage.

As I’ve mentioned several times above simply taking vitamin B12 by mouth isn’t enough to get it into your body or into your cells.

In order for B12 to be properly absorbed you need all of the following to be working perfectly:

1. Adequate amounts of stomach acid and hydrochloric acid

2. Adequate amounts of intrinsic factor

3. Functioning pancreas with adequate amounts of proteases and enzymes

4. Functioning small intestines and villi (without inflammation)

5. Proper metabolism of B12 in the body and cells

You can see that the first 4 steps all require proper function in the GI tract.

But the problem with that is how many of you suffer from SOME kind of gastrointestinal disorder?

I’m talking about any of the following:

  • Chronic constipation
  • Acid reflux
  • Irritable bowel syndrome
  • Diarrhea or loose stools
  • Acid reflux
  • Small intestinal bacterial overgrowth
  • Small intestinal fungal overgrowth
  • Inflammatory bowel disease
  • History of using acid blockers like proton pump inhibitors or H2 blockers

Just one of these conditions is enough to interfere with the absorption and the first three steps of vitamin B12 absorption (and this doesn’t include vitamin b12 metabolism).

With as many as 20% of the population with IBS alone(17), it’s not hard to see how so many patients may be taking oral forms of vitamin B12 without any benefit.

That may explain oral and liquid forms of B12, but what about sublingual forms of B12?

In my experience (having the advantage of treating hundreds of patients with both sublingual and shots/injection forms of B12) I can say that sublingual forms are not always rapidly absorbed and utilized by the body.

Although it seems that physiologically it would be absorbed and utilized it seems not to be the case in the majority of patients I treat.

Something similar happens with sublingual HCG vs HCG injection.

Theoretically, there should be complete absorption but it appears not to be the case.

It probably has more to do with the utilization of the B12 vs the actual absorption.

Intramuscular and subcutaneous injections have the advantage of being slowly absorbed over a period of time without undergoing thefirst-pass metabolism in the liver as supplements that are absorbed via the GI tract do.


Instead, subcutaneous and intramuscular injections are readily available at the cellular level for the tissues in which they are injected causing symptomatic relief very quickly.

What many patients underestimate is their body’s ability to both absorb and utilize nutrients and vitamins.

So consider this:

The sicker you are, the more nutrients and vitamins you need and the more energy it will take to both absorb and utilize these nutrients.

It’s a vicious cycle.

In addition, if you’ve ever been to the hospital you know how effective intramuscular and intravenous administration of medications and nutrients can be.

When you are septic with a systemic infection Doctors will always give you IV forms of antibiotics instead of oral pills, that’s because more is bioavailability and action.

The same is true for strep throat infections.

Have you ever had a penicillin or another antibiotic injection? It works much more rapidly than taking oral pills.

This same principle is applied to nutrient and vitamin deficiencies like vitamin B12 deficiency.

Vitamin B12 Injections and Dosage: How much do you need?

So how much vitamin B12 do you need if you use shots or injections?

Well, you actually need much less than oral forms of B12 including sublingual preparations.

This is another testament to the fact that subcutaneous and intramuscular injections are more rapidly absorbed and utilized!

Generally, the dosage for B12 in oral forms ranges from 1,000-5,000mcg taken each day.

Compare that to the dose of methylcobalamin used in the shot and injection form which is 5,000mcg taken every 7 days.

So oral forms you need to take 7 times the dose (and it needs to be taken daily) and even at these doses, the oral forms don’t necessarily impact symptoms.

Another advantage of IM and subcutaneous injections is that they provide a more stable release of nutrients into the body(18).

That means you get a constant release of vitamin B12 into your body which is sustained throughout the week.

This sustained release of vitamins helps prevent crashes that can occur by taking oral medications or especially if an oral dose is skipped or missed.

So where do you inject vitamin B12?

I have successfully used both intramuscular and subcutaneous routes of administration for methylcobalamin.

More recently I prefer the subcutaneous route because you can use insulin needles + syringes and it’s less painful for the injection plus the absorption and results are similar to the intramuscular route.

Where do you inject into your body?

  • Intramuscular route: Mid-thigh, deltoid area, or glut region (thigh is the easiest if doing it on yourself)
  • Subcutaneous route: Same locations but you can also include areas like the abdomen

How frequently do you inject into your body?

Generally, every 7 days is recommended to start, but occasionally I will increase or decrease the frequency depending on how the vitamin is tolerated.

Methylcobalamin vs Cyanocobalamin

Not all forms of vitamin B12 are created equal.

Like many other nutrients – I’m looking specifically at you magnesium – some forms are cheaper and far less effective than others.

This is especially important when it comes to vitamin B12.


Because as many as 40% of the population has issues with B12 metabolism due to genetic mutations at the MTHFR locus.

What this means is that certain forms of B12 can get “caught” up during the metabolic process which means they aren’t available to be used by the body and in some cases can make patients feel worse.

In patients who have this abnormality providing the body with excess methylation groups (which comes in methylcobalamin) helps to keep the B12 in the body longer and helps the tissues utilize the B12.

So there is a big difference in terms of the effectiveness of B12 that depends on what is bound to the cobalamin infrastructure.

Whenever possible avoid the cyanocobalamin forms of B12 (you can easily check which form your B12 comes in by looking at the active ingredients section on the back of your vitamins) and take preference for methylcobalamin.

What’s interesting is that many “weight loss clinics” and even physicians use cyanocobalamin when giving patients injections or shots.

Even though giving shots and IM B12 is superior to oral forms, if you are using cyanocobalamin you still aren’t getting the best results.

In this case, it’s very important to use methylcobalamin for injections and shots.

This will allow even better results in terms of symptomatic relief.

This also may explain why some people who have had B12 shots elsewhere seem to improve more when I give them methylcobalamin instead of cyanocobalamin.

Frequently Asked Questions about Vitamin B12 Shots

After reading this you may have more questions about using vitamin B12 shots and injections.

I’ve provided these frequently asked questions sections to answer those questions.

This information is based on my experience in treating hundreds of patients with high-quality, pharmaceutical grade B12, and my results.

Where can I get the right form of B12 shots?

Finding high-quality methylcobalamin B12 shots can be difficult unless you are looking in the right place.

You can usually find them locally if you look for an integrative physician’s office but make sure they are the following:

  • Methylcobalamin 5,000mcg dosage (don’t get 1,000mcg dosage forms or you’re only getting 1/5th the dose)

Frequently offices may try to give out 1,000mcg dosages of cyanocobalamin because it’s cheaper – you will want to avoid this type of dosage and form of B12.

They also need to be shipped on ice and should preferably include needles + syringes.

Remember not all forms of B12 are created equal.

Will B12 shots work for me?

It’s hard to say for sure.

In my experience, about 60-70% of patients benefit from taking B12 shots in some way.

The most common benefit is more sustained energy levels without crashes throughout the day.

If you’ve been on high-quality B12 shots previously and didn’t notice a benefit then they aren’t likely to produce significant results in your body.

I generally recommend B12 shots as part of an entire and comprehensive treatment plan instead of being used in isolation, but many patients swear by using them alone.

At the end of the day remember this:

There is very little risk to using B12 shots and the benefits may be tremendous. When in doubt it is worth a trial especially if you’ve tried oral forms of vitamins and B12 that haven’t worked.

Where do I inject the B12 shots?

It depends on the length of the needle and whether or not the injection is subcutaneous or intramuscular.

I prefer to use the subcutaneous route which means the needle is much smaller and can be used in more places on the body: abdomen, thigh, gluteal region, and shoulder/deltoid region.

If you use intramuscular you are limited to using a place in the body like the thigh or deltoid (shoulder area).

Does it matter if the shots are subcutaneous or intramuscular?

Subcutaneous injections tend to be better tolerated (have less pain) and don’t go as deep into the tissues so trauma and bleeding are less.

Subcutaneous injections increase compliance and have similar efficacy to intramuscular injections.

(Video) How to Use B12 Shots for Weight Loss (BENEFITS + HOW MUCH You Need)

In the end, it doesn’t necessarily matter but comes down to a matter of preference.

How often can I use B12 shots?

I generally recommend 5,000mcg once per week, but sometimes patients can decrease the total dosage and increase the frequency of shots.

So, for instance, using 3,000mcg every 3 days may be better tolerated and provide a more sustained energy level in some patients.

I generally base my frequency on a combination of labs, patient symptoms, and how much the patient is improving.

Can you get too much B12 in the shots?

Vitamin B12 is a water-soluble vitamin.

That means it can safely be eliminated in your bloodstream and filtered through your kidneys (as long as your kidneys are functioning normally).

High toxicity and hypervitaminosis come from high doses of fat-soluble vitamins because these vitamins can be deposited into fat cells and stay in the body longer.

Any excess vitamin B12 is simply urinated out of your body.

It’s common for patients to have high serum levels of vitamin B12 after vitamin B12 shots and injections which, to an untrained eye, can make it seem like you are getting too much vitamin B12.

This isn’t a concern because the serum level of B12 doesn’t necessarily correlate with cellular levels of B12 due to metabolic issues, etc.

So in these cases, uninformed Doctors may express concern over serum levels when it isn’t appropriate.

In fact, during treatment and in severely deficient patients, I like to see serum vitamin B12 levels > 1,000 (which is technically “high” by lab reference ranges).

Bottom line:

It’s almost impossible to become toxic on vitamin B12 unless you have kidney issues.

Are B12 shots safe?

Yes, vitamin B12 shots are safe to use.

The biggest risk comes from the injection.

Whenever anything is entering into your body there is a small risk of bleeding or infection.

In over 1,000 vitamin B12 shots, I’ve never seen anyone have any issues with either, but there is a theoretical risk factor for both.

The most common side effect that I see are positive side effects.

Negative side effects may include a paradoxical decrease in energy levels (most likely due to detoxification from methylation) or slight pain at the injection site which diminishes over 5-10 days.

All in all, B12 shots are both safe and efficacious.

How big are the needles?

When using the subcutaneous route the needles really aren’t that large.

You can see an example below:

B12 Shots Benefits & How to Use Them For Weight Loss (3)

Subcutaneous needles are insulin syringes and the length of the need varies from 6mm to 12mm which is less than 1 cm. Remember that 2.5 cm = 1 inch, so we are talking significantly smaller than 1 inch.

In very lean individuals you can actually use insulin syringes to reach the depth of the muscles if you push hard enough on the skin.

Can I use sublingual B12 or oral forms of B12 instead of shots?

You are certainly welcome to use whatever form of B12 works well for you.

If you are currently using sublingual or oral forms of B12 and you are getting symptomatic relief then I wouldn’t recommend changing up your method of administration.

But if you are still experiencing symptoms or you have any of the medical conditions listed above, then a trial of B12 shots is certainly worthwhile.

In these situations, I recommend B12 shots as first-line therapy over oral forms.

If you would prefer to start out with sublingual forms and oral B12 then I recommend this supplement.

Are there any disadvantages to using B12 shots? What are the risks?

B12 shots are generally safe as long as proper precautions are taken for the injections.

Any negative side effects come from the very small risk of bleeding or infection after the shot.

In general, risks are very low but do occur occasionally.

Disadvantages of using shots include some pain at the injection site.

Disadvantages of using oral forms: inferior absorption, inferior cellular activity, require high compliance with daily dosing.

The right choice over oral or shot form depends on you and your situation.

Can I use both B12 shots and oral forms of B12?

I have many patients who use both oral forms with B12 shots and injections.

Some patients feel that B12 shots provide a very sustained and consistent energy level throughout the week but like to supplement and augment this effect with oral forms on particularly stressful days.

It is safe to use both forms simultaneously (provided you have functioning kidneys).

How long do I need to be on B12 shots?

This depends on your personal situation, how low your vitamin B12 levels are intracellularly, what kind of medical conditions you have, and how much improvement you get from the B12 shots.

I always recommend a series of 10 shots taken every 7 days over 10 weeks.

This allows for a sufficient trial length and will allow for enough B12 to make a difference over a sustained period of time.

Most patients who experience significant relief will notice it almost immediately.

Many patients experience significant improvement in symptoms within days of the first shot.

Others don’t notice a difference unless they forget to take their shot after 7 days, or they feel the effects wear off after 3-5 days.

How you react largely depends on your specific situation.

After 10 weeks or injections you have several options:

1. Recheck blood work including MCV, hgb (if anemic), serum B12, and homocysteine.

You should be able to see your MCV increasing, your homocysteine dropping, and your serum B12 level increasing.

These are indications that your B12 is working.

You can simply base your length of treatment on these values until you get to the optimal range if you’d like.

Alternatively (and this is the approach I take for many patients), if you are experiencing significant symptomatic improvement then you can just continue to take the B12 shots indefinitely.

I have many patients who feel so great with B12 shots they simply continue taking them each week regardless of what their labs show.

Take whatever approach works best for your situation.

If you are unsure how to proceed you can always take a series of 10 shots and then monitor your symptoms after you are done to see if they get worse on weeks 11-13.

If your symptoms worsen then you can simply go back on the B12 shots.

Are there side effects to B12 shots?

Side effects should primarily be positive:

Meaning an increase in energy levels, decrease in crashes, improvement in hair growth (or decrease in hair loss), improved concentration, decreased depression, etc.

Negative side effects occur rarely and include a decrease in energy levels (which happens in about 2-3% of my patients).

(Video) B12 Shots: Immunity Boost & Other Benefits - IBI Healthcare Institute

For patients who experience a paradoxical decrease in energy levels, it doesn’t mean you should stop taking the B12 but instead decrease your dose by half (so take 2,500mcg every 7 days) or simply take 5,000mcg every 14 days instead.

This is usually an indication that you have a methylation defect and need to slow down on the amount of B12 you are taking.

Should I get labs before I use B12 shots?

You don’t necessarily have to get labs as a baseline if you are symptomatic (symptoms listed above).

If you prefer to get labs as a reference range you can use the list of labs above.

Will B12 shots interfere with my prescription medications?

Actually, it’s generally the other way around.

Many medications actually DECREASE your vitamin B12 levels and are more likely to make you deficient.

Medications in this category include: Metformin, H2 blockers and PPI (proton pump inhibitors) used to block acid production in the GI tract. Nitrous oxide can also deplete B12 levels.

As long as you take the B12 via shot form or injection form it should not have an effect on any other medications you may be taking.

Can I get B12 shots from my regular Doctor or Primary care physician?

Generally, primary care physicians are not used to using the proper form or dose of B12 levels.

We still have physicians using vitamin D2 instead of D3 when we have studies showing (19) D3 to be far more efficacious than D2.

Vitamin B12 is no different.

You can try to use your primary care physician as long as you use the recommended settings above but beware:

Most physicians are not used to dosing vitamins and are very unfamiliar with them in general.

This leads to underdiagnosis and mismanagement.

Whenever possible avoid getting B12 shots from your PCP unless they also have some background in integrative medicine.

When should I take the B12 shots?

Because some patients do experience a significant increase in energy levels after taking even their first shot it is best to use it first thing in the morning.

That way the sustained energy levels will not interfere with your bedtime routine or keep you up.

Even using this strategy some patients (minority) do have issues with sleep for the first 1-2 days after each injection.

This can be combated by simply reducing the dosage by half and increasing the frequency of the injections

B12 shots should be taken on the same day of each week and every 7 days.

So something like every Sunday morning should work well for most patients.

Remember consistency is important.

Does B12 need to be refrigerated?

Yes and B12 should be shipped with an ice pack to maintain temperature levels.

All B12 shots shipped from my office come with ice packs and instructions for refrigeration upon arrival.

Will insurance cover B12 shots?

Unfortunately no, insurance will not cover B12 shots.

When it comes to vitamins and nutrients you are usually on your own even though there is significant evidence that they provide relief and can help many patients.

Recap & What to do Next

If you have any other questions please post them below and I will provide a detailed answer to this frequently asked question portion.

I strongly believe in the use of B12 shots because I’ve found them to be so helpful in many situations.

No, they aren’t miracle supplements by themselves, but if used appropriately and as part of a comprehensive treatment plan they can be very powerful.

If you have persistent, chronic fatigue, decreased hair loss, depression (or anxiety) or suffer from any of the other symptoms listed above you may benefit from B12 shots.

Now it’s your turn:

Have you used B12 shots successfully in the past?

Did they work for you? why or why not?

Do you have thyroid problems, if so have you tried B12 shots?

Leave your questions and comments below!

#1. https://www.ncbi.nlm.nih.gov/books/NBK6561/

#2. https://www.ncbi.nlm.nih.gov/pubmed/18655403

#3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3263877/

#4. https://www.ncbi.nlm.nih.gov/pubmed/25902009

#5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1570488/

#6. https://www.ncbi.nlm.nih.gov/pubmed/15681626

#7. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3856388/

#8. https://www.ncbi.nlm.nih.gov/pubmed/15029091

#9. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2294086/

#10. https://www.ncbi.nlm.nih.gov/pubmed/8435917

#11. https://ods.od.nih.gov/factsheets/VitaminB12-HealthProfessional/

#12. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1570488/

#13. https://www.ncbi.nlm.nih.gov/pubmed/11553056

#14. https://www.ncbi.nlm.nih.gov/pubmed/15831132

#15. https://www.ncbi.nlm.nih.gov/pubmed/11553056

#16. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1905232/

#17. http://emedicine.medscape.com/article/180389-overview

#18. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4494621/

(Video) Do B12 Injections Help with Weight Loss? | The SASS with Susan and Sharzad

#19. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3349454/

B12 Shots Benefits & How to Use Them For Weight Loss (4)


How many B12 injections do I need to lose weight? ›

Most weight loss patients only need about one weekly injection. However, you may need them more or less often. It depends on your progress and how you respond to the injections. Because vitamin B-12 is water soluble and lipotropic components are safe, you don't have to worry about getting too much.

When should I take B12 for weight loss? ›

“Take water-soluble vitamins on an empty stomach with a glass of water,” recommends Dr. Perez-Gallardo. And since it can be energizing, Dr. Perez-Gallardo says that the best time to take vitamin B12 is in the morning, so it won't affect your sleep.

How many B12 shots should I take a day? ›

B12 may be injected into a muscle or under the skin at 100 mcg daily for a week, every other day for another week, and then every three or four days for a month. Thereafter, 100 mcg should be injected once a month for life.

How long does it take for a B12 shot to start working? ›

Since B12 shots are injected intramuscularly bypassing the digestive process, they start to work immediately. Typically, our patients experience positive effects between 24-72 hours after the treatment.

Does B12 help lose belly fat? ›

The body relies on a variety of vitamins to maintain optimal health, and B12 is among the most important for weight management. If you want to lose excess weight, vitamin B12 is not only energy-enhancing, it has also been linked to weight loss.

Does B12 speed up your metabolism? ›

B12 works by converting the food we eat into sugar and other types of fuel that keep the body running smoothly. B12 is often associated with weight loss because of its ability to boost metabolism and provide lasting energy.

Do shots of B12 help weight loss? ›

There's no solid proof that vitamin B-12 shots, also called injections, help you lose weight. Vitamin B-12 is a water-soluble B complex vitamin. It's found naturally in many foods, such as meat, fish and dairy products. Vitamin B-12 is added to some foods and is available as a dietary supplement.

What is the injection for weight loss? ›

Injecting botulinum toxin into the stomach wall temporarily relaxes the muscles and slows stomach emptying. The procedure can help you feel full longer after eating, making it easier to eat less and lose weight.

How long does a B12 shot last? ›

Simply put, how long the B12 shot will last is different for everyone. Though it differs a bit from one person to another, the effects of B12 vitamins usually last around 48 hours to 72 hours after the initial injection.

Can you take B12 shots long term? ›

If your vitamin B12 deficiency is not caused by a lack of vitamin B12 in your diet, you'll usually need to have an injection of hydroxocobalamin every 2 to 3 months for the rest of your life.

Can I take a B12 shot everyday? ›

How Often Do You Need a Vitamin B12 Injection? The usual frequency for intramuscular doses of B12 shots is every 10 days, followed by maintenance doses at varying intervals. After this period, injections can be administered once per month, which this frequency is enough to reverse the signs of vitamin B12 deficiency.

Do I have to take B12 shots forever? ›

Your doctor will probably check your blood every now and then to make sure your B12 levels are normal. If you have pernicious anemia or another condition that doesn't go away, you may need shots or supplements forever.

What happens after your first B12 shot? ›

Pain/redness at the injection site, mild diarrhea, itching, or a feeling of swelling all over the body may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

How do you feel after first B12 injection? ›

Upon receiving the B12 injection, you may experience a skin reaction in or around the area in which the injection was placed. Pain, redness, and swelling may occur shortly after the procedure is complete. There may also be some irritation in the area, as well as a risk of infection.

How do you feel after vitamin B12 shot? ›

Nervous System Reactions

After getting a vitamin B12 injection some people may experience a disturbance to the nervous system. These symptoms may include dizziness, difficulty walking normally, nervousness, anxiety, weakness and uncoordinated movements.

What is the best vitamin for belly fat? ›

A 2011 study found that overweight and obese adults taking calcium and vitamin D supplements lost significantly more stomach fat than people not taking any supplements. Food sources: While the sun is the best source of vitamin D, you can also get this vitamin from food, especially fortified foods.

Does B12 help your hair grow? ›

One of those vital nutrients is B12, also known as cobalamin. B12 promotes healthy hair growth by assisting in the production of oxygen-rich red blood cells, which feed hair follicles.

What vitamin helps with weight loss? ›

Vitamins B, D, iron, and magnesium are four well-known weight reduction vitamins. Vitamin B helps the body to convert food into energy. It also plays a role in metabolism and cell function. A lack of vitamin B can lead to fatigue and weight gain.

What is the difference between a B12 shot and B12 vitamins? ›

B12 injections can be more effective than the pills in certain patients who have trouble absorbing vitamin B12. In the majority of patients the pills are just as good as the injections.

Does B12 effect appetite? ›

Decreased appetite and weight loss. As a result of digestive problems, such as nausea, people with vitamin B-12 deficiency may lose their appetite. A decreased appetite can lead to weight loss in the long term.

What does B12 do to fat? ›

If you want to lose excess weight, vitamin B12 has been linked to weight loss and energy enhancing. Vitamin B12 plays a major role in the body's essential functions, including DNA synthesis. Vitamin B12 also helps the body convert fats and proteins into energy.

How much weight can you lose with B12 lipotropic injections? ›

How much can you lose? Although the results vary for every person depending on many factors unique to the individual (such as do they exercise regularly, their caloric intake, etc.), lipotropic injections reviews have reported losing between two to four pounds a week.

What is the weekly shot for weight loss? ›

In June 2021, the FDA approved semaglutide (Wegovy), a once-weekly injection, for chronic weight management when used in combination with a healthy diet and exercise. The medication had made headlines before its approval when the manufacturer reported 15% to 18% weight loss findings during clinical trials.

What is the safest weight loss injection? ›

What is the best weight loss injection? Based on the evidence above, when comparing one to another, Saxenda comes out on top for us. It's the safest, most effective and produces the best results in our experience.

Where do you inject weight loss shots? ›

The best sites for injecting are the front of your waist (abdomen), the front of your thigh or the upper arm. You must take extra care not to inject into a vein or muscle.

What happens when you stop taking B12 shots? ›

Do not stop using the medicine unless your doctor tells you to. Untreated vitamin B12 deficiency can lead to anemia or irreversible nerve damage.

How much does a B12 shot cost? ›

The cost for Vitamin B12 injectable solution (1000 mcg/mL) is around $90 for a supply of 25 milliliters, depending on the pharmacy you visit.
Injectable Solution.
QuantityPer unitPrice
25 (25 x 1 milliliters)$3.61$90.35

Where do I inject B12 shots? ›

The easiest site when self-administering an IM injection is the middle third of the vastus lateralis muscle of the thigh. Other options include the deltoid muscle of the upper arm and the dorsogluteal site on the bottom. This maybe useful if you have a carer or a family member willing to administer your injection.

What are B12 shots good for? ›

What's all the Buzz About Vitamin B12 Shots?
  • Increase energy levels and combat fatigue.
  • Speed up metabolism.
  • Help improve sleep patterns.
  • Increase concentration.
  • Improve mood.
  • Boost the immune system.
  • Help with weight loss.
  • Possibly help with hair growth or stop hair loss.

When is the best time to take B12 shot? ›

Vitamin B12, for example, should definitely be taken in the morning. This is because it is important for energy metabolism, which may interrupt your sleep if taken at night.

Does B12 need to be refrigerated? ›

Vitamin B-12 is stable at room temperature. It doesn't need to be refrigerated.

How does B12 affect the liver? ›

The researchers also found that supplementing with vitamin B12 and folic acid increased levels of syntaxin 17 in the liver, restoring its role of digesting fat and protecting against inflammation. Vitamin B12 supplementation also slowed NASH progression and reversed liver inflammation and fibrosis.

How do I know if B12 injections are working? ›

B12 injections work quickly; they are the most effective way for your body to absorb Vitamin B12. Within 48 to 72 hours, your body will begin to make new red blood cells. For mild deficiencies, you may need two to three injections over several weeks to notice peak impact.

What medications should not be taken with B12? ›

Taking omeprazole (Prilosec), lansoprazole (Prevacid) or other stomach acid-reducing drugs might decrease your body's ability to absorb vitamin B-12. Vitamin C (ascorbic acid) supplements. Taking vitamin B-12 with vitamin C might reduce the available amount of vitamin B-12 in your body.

Who should not take B12 injections? ›

Vitamin B12 shots may not be suitable for people with a history of:
  • sensitivity to vitamin B12.
  • Leber's disease, which affects the optic nerve.
  • kidney problems.
  • hypokalemia, or low potassium levels.
  • deficiencies in other nutrients, particularly folic acid and iron.

How long does it take for B12 injections to make a difference? ›

B12 injections work quickly; they are the most effective way for your body to absorb Vitamin B12. Within 48 to 72 hours, your body will begin to make new red blood cells. For mild deficiencies, you may need two to three injections over several weeks to notice peak impact.

Can you overdo B12 injections? ›

A number of studies show that megadoses – especially from vitamin B12 injections – can cause outbreaks of acne and rosacea. Rosacea is a skin condition that forms red patches on your face. Some evidence implies that very high doses of vitamin B12 can cause complications if you have diabetes or kidney disease.

How long does it take to see results from B12 lipotropic injections? ›

Once you begin treatment, you may notice some initial improvements within the first few weeks of treatment. Typically, the most noticeable improvements occur within 30 days of beginning the treatment process.

How much weight can I lose in a week with lipotropic injections? ›

You can expect a gradual transformation of your body when you combine lipotropic injections with a regimented diet and exercise plan. Because body types vary, some people will lose weight faster than others, but in general, most people report losing about 2 to 4 pounds per week.

What injections help with weight loss? ›

Wegovy (semaglutide) and Saxenda (liraglutide) are both injectable medications FDA-approved for weight loss. Wegovy is injected once weekly. Saxenda is injected once daily.

What to expect after getting a B12 shot? ›

Pain/redness at the injection site, mild diarrhea, itching, or a feeling of swelling all over the body may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

Does B12 give you energy right away? ›

While B vitamins DO help give you energy, it's not instantaneous. (That surge in energy you feel is from the caffeine also loaded into the bottle.)

What should you not do after a B12 shot? ›

Avoid strenuous exercise for 48 hours after your treatment. Avoid touching the injection site for 6 hours after your treatment. You may experience a dull ache at the injections site for around 1 hour after your treatment. Avoid any blood thinning medication.

Can I have a B12 injection every week? ›

Yes you can, a client can come to you for an injection every week, until they start to feel the benefits. Although after 4 to 6 injections if they do not feel any benefits then there is a possibility that the B12 is more than likely not going to be effective.

Can I take B12 shots twice a week? ›

For the majority of people, I recommend once weekly for 4 weeks. Then B12 shots can be helpful monthly as maintenance. If we are treating autoimmunity or pernicious anemia, you will receive B12 weekly or twice weekly for 6-12 weeks.

What is the difference between B12 injection and B12 lipotropic injections? ›

The primary difference between B12 injections and lipotropic injections is that lipotropic injections contain several ingredients that work together to enhance energy metabolism processes, facilitate fat burning, and promote weight loss.

What is the difference between B12 shots and lipotropic shots? ›

What is the difference between B12/Lipo Shots and B12 Shots? While both contain Vitamin B12, Lipotropic injections offer additional nutrients that further enhance weight loss. Common lipotropic nutrients include Methionine, Choline, Inositol, and Betaine. Each is responsible for maintaining a healthy liver.

Where do u inject B12? ›

The easiest site when self-administering an IM injection is the middle third of the vastus lateralis muscle of the thigh. Other options include the deltoid muscle of the upper arm and the dorsogluteal site on the bottom. This maybe useful if you have a carer or a family member willing to administer your injection.


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