Sublingual Vitamin B12: Is Taking Supplements under Your Tongue More Effective? | Ro (2024)

table of contents

  1. Can all supplements be taken sublingually?
  2. Is sublingual vitamin B12 more effective than other forms of the vitamin?
  3. Why do you need B12 supplements?
  4. How to use sublingual B12 supplements
  5. Do vitamin B12 supplements have side effects?
  6. Symptoms of a vitamin B12 deficiency
  7. Who is most at risk of a B12 deficiency?
  8. Other sources of vitamin B12


If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.

When scientists develop medications and supplements, they have to take into account that any pill you swallow has a long and treacherous route to travel before reaching your bloodstream.

Active ingredients have to be packaged so they’re protected from the extreme acid of your stomach, as well as all of the digestive enzymes they meet along the way. Once a medication is absorbed from the digestive tract into your bloodstream it has to pass through the liver, which can break down or significantly alter active ingredients. Every obstacle along the way alters the amount of each active ingredient.

That’s where sublingual treatments come in. It turns out that the spot under your tongue is sort of like a trap door. When you put a medication under your tongue, it goes straight into the bloodstream, bypassing digestive juices and the liver’s filtration system. It’s a fast and effective method, but you shouldn’t be taking all your pills sublingually—here’s why.

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Can all supplements be taken sublingually?

Drugs are designed a specific way for a reason. So placing a pill that’s designed to be swallowed under your tongue instead can be dangerous and even deadly. Also, sometimes drug researchers take advantage of these obstacles and create inactive ingredients that need to go through your liver in order to be activated. That’s why you should always take medications as directed.

When it comes to vitamin B12, your body needs this essential vitamin to build red blood cells, get energy out of the food you eat, support your nervous system, and more. Since our bodies can’t produce B12 on their own, we have to get it from our food (like meat and dairy products), but not everyone gets enough. Manufacturers have created products like breakfast cereals and non-dairy milk fortified with B12 to tackle this problem, but many people still have a B12 deficiency.

If your healthcare provider diagnoses you with a B12 deficiency, they may recommend that you start taking a supplement, which is available in pill form that needs to be swallowed as well as in a sublingual form you just pop under your tongue. If you have a severe deficiency, they may offer you a vitamin B12 injection.

For people with low levels of this important vitamin, supplements are often a first choice. Vitamin B12 comes in many forms, however, sublingual B12 (taken under the tongue) is one option (NIH, 2020).

If you’re looking to take vitamin B12 supplements and are considering the sublingual route, here’s what you need to know.

Is sublingual vitamin B12 more effective than other forms of the vitamin?

Well, while the sublingual route would seem to be more effective in theory, research doesn’t actually back it up. Compared to other types of vitamin B12 supplements, the sublingual method doesn’t seem to be any more or less effective.

A study from 2006 didn’t find any difference in effectiveness between sublingual and oral vitamin B12 supplements (Yazaki, 2006). Another study concluded that the sublingual and oral method were equally effective in resolving B12 deficiency in participants (Sharabi, 2003).

Comparing the sublingual method to vitamin B12 injections, research found that taking B12 under the tongue had a higher absorption rate, making it a better option (Bensky, 2019).

Taking vitamin B12 sublingually may also be a good option for people with a condition called pernicious anemia. This condition is characterized by a lack of intrinsic factor, a protein that plays a crucial role in helping the body absorb vitamin B12 (Ankar, 2020).

Intrinsic factor is produced by the cells that line your stomach, and is one of the main components that drives your B12 intake capacity. People with pernicious anemia, may benefit from sublingual B12 as they lack intrinsic factor and have a lot of trouble absorbing B12 through their digestive system (Ankar, 2020).

Why do you need B12 supplements?

Vitamin B12, also known as cobalamin, is a molecule that isn’t easily absorbed into our systems.

Research has shown that even in people without any underlying health conditions, when taking a 500 microgram oral supplement, only 10 micrograms (or 2%) is absorbed (Carmel, 2008). Improving absorption rates is a good way to make sure you get what you need.

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Sublingual supplements come tablets or liquid drops. If you’re trying the liquid method, you put drops under your tongue instead of ingesting them like you would an oral supplement. The thought behind administering it under the tongue is that it can be absorbed directly into the bloodstream through what’s called the mucous membrane in your mouth (UMichigan Health Library, 2018). This method is thought to enhance absorption, but research doesn’t fully confirm this.

Nonetheless, sublingual B12 is a viable way to supplement B12 levels for people deficient in the vitamin. This method may also be useful for children or individuals who have trouble swallowing pills.

How to use sublingual B12 supplements

If you’re a first time sublingual B12 user (that’s a mouthful), here’s what you should know.

Sublingual B12 supplements come in two forms: tablets and liquid drops. Whichever you decide on, the idea is to place the correct amount under your tongue and let it dissolve completely—without swallowing (UMichigan Health Library, 2018).

Sublingual tablets come in 500 or 1000 mcg dosages. The recommended daily intake of B12 is between 2.4 and 2.8 mcg, but its low absorption rate is the reason for such high dosages in supplements (NIH, 2020).

Do vitamin B12 supplements have side effects?

Vitamin B12 supplements are generally considered safe. Those with severe deficiencies may require higher doses of vitamin B12, which can cause side effects including dizziness, headache, anxiety, nausea, and vomiting (Al Amin, 2021). If you’re unsure what dosage you need, a healthcare professional can help determine the appropriate amount.

Symptoms of a vitamin B12 deficiency

Not getting enough vitamin B12 can cause some unpleasant symptoms. Common signs of B12 deficiency include fatigue, weakness, constipation, loss of appetite, and weight loss (NIH, 2020).

A B12 deficiency is more common in older adults, with past surveys showing that roughly 6% of people 60 years and older aren’t getting enough vitamin B12. The prevalence of this deficiency also increases with age (Allen, 2009).

Because B12 is critical for proper nervous system function, a deficiency can lead to neurological symptoms, such as confusion, poor memory, depression, and difficulty maintaining balance (Serin, 2019). These symptoms can also be caused by other health conditions or vitamin deficiencies, therefore it’s important to see a healthcare professional and get properly diagnosed.

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Who is most at risk of a B12 deficiency?

Some individuals are more prone to a B12 deficiency than others. People at risk of a vitamin B12 deficiency usually have conditions that hinder the absorption of B12 from their gastrointestinal system.

Here are some of the groups who may be more at risk for a B12 deficiency (NIH, 2020):

  • Those with atrophic gastritis: Between 10 and 30% of older adults are afflicted with atrophic gastritis, which results in decreased absorption of foods containing B12.
  • People with pernicious anemia: Individuals with pernicious anemia may also be at risk for B12 deficiency. Individuals with this condition lack the intrinsic factor we mentioned earlier, which is one of the key proteins responsible for B12 absorption (O’Leary, 2010).
  • Individuals with gastrointestinal issues: People living with disorders of the stomach or small intestine may have a more difficult time absorbing vitamin B12 from their food. In addition, patients who’ve undergone gastrointestinal-related surgeries may be at risk of B12 deficiency due to malabsorption.
  • Vegetarians and vegans: Since most foods that contain B12 naturally are animal products like meat, eggs and dairy, vegetarians and vegans are at greater risk of developing a B12 deficiency.

Other sources of vitamin B12

Sublingual vitamin B12 is not the only solution if you’re lacking in the B12 department. Below are some of the main ways you can get more vitamin B12 in your system:

  • Diet: Animal products like poultry, meat, fish, eggs, and milk contain vitamin B12. Foods, such as cooked clams and beef, provide well over the recommended daily intake of B12. Trout, salmon, tuna, and fortified yeast also give you just the right amount. Vitamin B12 is not typically found in plants, so vegans and vegetarians may need to look for fortified breakfast cereals that include B12 or opt for a regular supplement (NIH, 2020).
  • Oral supplements: Cyanocobalamin and methylcobalamin are popular types of B12 supplements. Cyanocobalamin is the synthetic version of B12, and methylcobalamin is the natural form (Al Almin, 2021). Both come in the form of oral tablets, capsules, and gummies, which are available at most drugstores.
  • B12 injections: Intramuscular injections of vitamin B12 is one of the most common forms of administration, but it must be done by a medical professional (Shipton, 2015). Intranasal treatment (via a nasal spray) of B12 is also available through a prescription (Andrès, 2018).

If you think you might be suffering from B12 deficiency, consult with your doctor to discuss what avenues of treatment are available for you to pursue. Rest assured that there are plenty of solutions out there to resolve B12 deficiency, whether it’s through sublingual/oral tablets, diet, or injections.


  1. Al Amin, ASM, Gupta, V. (2021). Vitamin B12 (Cobalamin). StatPearls. StatPearls Publishing. Retrieved from
  2. Allen, L. H. (2009). How common is vitamin B-12 deficiency?. The American Journal of Clinical Nutrition, 89(2), 693S–6S. doi: 10.3945/ajcn.2008.26947A. Retrieved from
  3. Andrès, E., Zulfiqar, A. A., Serraj, K., Vogel, T., & Kaltenbach, G. (2018). Systematic Review and Pragmatic Clinical Approach to Oral and Nasal Vitamin B12 (Cobalamin) Treatment in Patients with Vitamin B12 Deficiency Related to Gastrointestinal Disorders. Journal of Clinical Medicine, 7(10), 304. doi: 10.3390/jcm7100304. Retrieved from
  4. Ankar, A., Kumar A. (2020). Vitamin B12 Deficiency. StatPearls. StatPearls Publishing. Retrieved from
  5. Bensky, M. J., Ayalon-Dangur, I., Ayalon-Dangur, R., Naamany, E., Gafter-Gvili, A., Koren, G., & Shiber, S. (2019). Comparison of sublingual vs. intramuscular administration of vitamin B12 for the treatment of patients with vitamin B12 deficiency. Drug Delivery and Translational Research, 9(3), 625–630. doi: 10.1007/s13346-018-00613-y. Retrieved from
  6. Carmel, R. (2008). How I treat cobalamin (vitamin B12) deficiency. Blood, 112(6), 2214–2221. doi: 10.1182/blood-2008-03-040253. Retrieved from
  7. Cyanocobalamin (oral). (2018, July 16). University of Michigan Health Library. Retrieved February 10, 2021, from
  8. National Institutes of Health, Office of Dietary Supplements. (2020). Vitamin B12. Retrieved February 10, 2021, from
  9. O’Leary, F., & Samman, S. (2010). Vitamin B12 in health and disease. Nutrients, 2(3), 299–316. doi: 10.3390/nu2030299. Retrieved from
  10. Serin, H. M., & Arslan, E. A. (2019). Neurological symptoms of vitamin B12 deficiency: analysis of pediatric patients. Acta Clinica Croatica, 58(2), 295–302. doi: 10.20471/acc.2019.58.02.13. Retrieved from
  11. Sharabi, A., Cohen, E., Sulkes, J., & Garty, M. (2003). Replacement therapy for vitamin B12 deficiency: comparison between the sublingual and oral route. British Journal of Clinical Pharmacology, 56(6), 635–638. doi: 10.1046/j.1365-2125.2003.01907.x. Retrieved from
  12. Shipton, M. J., & Thachil, J. (2015). Vitamin B12 deficiency – A 21st century perspective. Clinical Medicine, 15(2), 145–150. doi: 10.7861/clinmedicine.15-2-145. Retrieved from
  13. Yazaki, Y., Chow, G., & Mattie, M. (2006). A single-center, double-blinded, randomized controlled study to evaluate the relative efficacy of sublingual and oral vitamin B-complex administration in reducing total serum homocysteine levels. Journal of Alternative and Complementary Medicine, 12(9), 881–885. doi: 10.1089/acm.2006.12.881. Retrieved from

Sublingual Vitamin B12: Is Taking Supplements under Your Tongue More Effective? | Ro (6)

Yael Cooperman, MD

Yael Cooperman is a physician and works as a Senior Manager, Medical Content & Education at Ro.

Sublingual Vitamin B12: Is Taking Supplements under Your Tongue More Effective? | Ro (2024)


Sublingual Vitamin B12: Is Taking Supplements under Your Tongue More Effective? | Ro? ›

Compared to other types of vitamin B12 supplements, the sublingual method doesn't seem to be any more or less effective. A study from 2006 didn't find any difference in effectiveness between sublingual and oral vitamin B12 supplements (Yazaki, 2006).

Does B12 absorb better under the tongue? ›

Although there are claims that certain forms—like sublingual tablets or liquids placed under the tongue to be absorbed through the tissues of the mouth—have better absorption than traditional tablets, studies have not shown an important difference.

What is the best way to take sublingual B12? ›

It is best if this medicine (cyanocobalamin sublingual tablets) is taken with a meal. Place under tongue and let dissolve all the way. Do not chew, suck or swallow tablet.

What is the best way to take vitamin B12 for absorption? ›

To absorb more B12, divide the dose over the course of the day and take separately from a B12-containing meal. If you take a higher dose, such as 100 mcg, you will absorb only about 1% of the amount above 2.4 mcg -- although this may be appropriate in some situations.

Why do you have to dissolve vitamin B12 under your tongue? ›

Rather than waiting for your gut to dissolve a B12 capsule that slowly makes its way into your system, sublingual B12 goes straight into your bloodstream, bypassing the digestive enzymes that can affect its potency.

How long do you have to keep sublingual B12 under your tongue? ›

Shake well before use. Place under the tongue. Hold there for 30 seconds before you swallow.

Does putting a pill under your tongue make it work faster? ›

As discussed, sublingual medications get absorbed by the tissue under your tongue and pass directly into the bloodstream. This may be an advantage if you have any health conditions that affect your GI tract or liver. They generallystart working faster than traditional oral medications.

Is 1000 mcg of sublingual B12 too much? ›

There is no upper limit for vitamin B12, and most supplements provide between 500 mcg to 5,000 mcg of B12 daily to meet various nutritional needs [2].

Which form of B12 is best absorbed? ›

Methylcobalamin. Methylcobalamin is the most bio-available type of Vitamin B12 which means the body absorbs it more easily.

What is the best time of day to take sublingual B12? ›

Vitamin B12

According to health experts at Click Pharmacy, as a general rule of thumb, take your B vitamins in the morning or with a meal. 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.

How can I make my B12 work better? ›

Usually, vitamin B12 deficiency anemia is easy to treat with diet and vitamin supplements. To increase the amount of vitamin B12 in your diet, eat more of foods that contain it, such as: Beef, liver, and chicken. Fish and shellfish such as trout, salmon, tuna fish, and clams.

Can I drink water after taking sublingual B12? ›

Vitamin C and vitamin B12 are water-soluble vitamins, which means you need water to absorb them. “Take water-soluble vitamins on an empty stomach with a glass of water,” recommends Dr. Perez-Gallardo.

How long does it take for sublingual B12 to work? ›

It may take a few weeks before your vitamin B12 levels and symptoms (such as extreme tiredness or lack of energy) start to improve.

What are the side effects of sublingual B12? ›

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

Can I just swallow sublingual B12? ›

Place the sublingual tablet under your tongue and let it melt. Some brands can also be swallowed. You might need to hold the medicine in your mouth for at least 30 seconds before you swallow.

Is it OK to take 1000 mcg B12 daily? ›

Even the lowest doses in B12 supplements are many times the recommended dietary allowance. Doses up to 1,000 mcg, though unnecessary, aren't harmful.

How much sublingual B12 is too much? ›

Since B12 is a water-soluble vitamin, it's generally considered safe, even at high doses. No Tolerable Upper Intake Level (UL) has been established for B12, due to its low level of toxicity.

How do you increase sublingual absorption? ›

drink plenty of water, 10-15 minutes ahead of taking your allergy tablets or drops. avoid eating 5 minutes ahead of taking your tablets or drops. use a mirror to make sure tablets or drops are properly placed under your tongue. if you can, avoid swallowing for 2-3 minutes, allowing absorption to take place.

What percent of sublingual B12 is absorbed? ›

Typically, about 56 percent of a 1-microgram dose of B-12 is absorbed, and that rate of absorption decreases drastically if you take more than 2 micrograms at a time, the Office of Dietary Supplements explains. For example, if you take a 500-microgram pill, your body absorbs only about 10 micrograms.

Can you drink water after sublingual? ›

Limit the amount of fluids you drink from 1 hour before using this medicine and until 8 hours after. Also avoid drinks containing caffeine or alcohol before bedtime. Keep the tablet under your tongue until it has fully dissolved.

How much faster is sublingual? ›

The onset of drug effect may also be quicker than with oral ingestion. In dentistry, triazolam generally reaches peak effect in 20 to 30 minutes sublingually, as compared to 30 to 45 minutes orally. Rectal administration may be used when other enteral routes are precluded, as in an unconscious or nauseated patient.

Why is sublingual more effective? ›

Drug absorption is relatively faster across the sublingual mucosa compared to the buccal mucosa due to the thinner epithelium. In addition to rapid absorption, the portion of drug that is absorbed through the blood vessels directly enters the systemic circulation and bypasses hepatic first-pass metabolic processes.

How much B12 should a senior take daily? ›

When you're in your 60s you should officially start getting blood tests to test for vitamin B12 deficiency. Around this age, you should be getting around 2.4 micrograms of B12 a day.

Is it OK to take 5000 mcg B12 daily? ›

A dosage of 5000 mcg of Vitamin B12 has been deemed a safe dosing amount. In fact, it is often recommended for those who have a health condition that affects their B12 absorption. Consultation with a qualified health professional is always recommended.

What is the safe amount of B12 to take daily? ›

Recommended Intakes
4–8 years1.2 mcg1.2 mcg
9–13 years1.8 mcg1.8 mcg
14–18 years2.4 mcg2.4 mcg
19+ years2.4 mcg2.4 mcg
3 more rows
Dec 22, 2022

Which vitamin B12 is best for seniors? ›

Best Overall: Methyl-Life® Active B12 Complete

Methyl-Life's® Active B12 Complete contains all three naturally occurring forms of B12: methylcobalamin, hydroxocobalamin, and adenosylcobalamin. These forms are recommended by doctors as superior to cyanocobalamin, especially for treating vitamin B12 deficiency.

What is the most effective B12? ›

Healthline's picks of the best vitamin B12 supplements
  • Best chewable: NOW Foods Methyl B-12.
  • Best spray: Garden of Life mykind Organic Whole Food B-12 Spray.
  • Best budget-friendly: Nature Made B12 Softgels.
  • Best allergen-free: Pure Encapsulations Methylcobalamin.
  • Best high dose: Amazon Elements Vitamin B12.
Oct 26, 2022

What is the fastest way to increase B12? ›

How to raise your B12 levels fast. The most common way to treat B12 deficiencies is by adjusting your diet. If this is unsuccessful, vitamin supplements may be recommended. If you're looking to boost the amount of vitamin B12 in your diet, you should eat more animal products, like meat, seafood, dairy and eggs.

What vitamins should not be taken with B12? ›

Vitamin C and B12

It's not advised to take vitamin C and vitamin B-12 at the same time, says Litt. That's because high doses of vitamin C can reduce the amount of vitamin B-12 that's absorbed and metabolized by the body, she says. Be sure to take vitamin C at least two hours after vitamin B-12.

Should you take B12 on a full or empty stomach? ›

For example, it's recommended that people with a B12 deficiency take B12 supplements on an empty stomach with water to promote maximal absorption.

Can I take vitamin D and B12 together? ›

Interactions between your drugs. No interactions were found between Vitamin B12 and Vitamin D3. However, this does not necessarily mean no interactions exist. Always consult your healthcare provider.

Why do I feel good after taking B12? ›

Vitamin B12 is needed for the production of serotonin, a chemical responsible for regulating mood. Vitamin B12 supplements may help improve mood in people with an existing deficiency.

Why won't my body absorb B12? ›

Pernicious anaemia causes your immune system to attack the cells in your stomach that produce the intrinsic factor, which means your body is unable to absorb vitamin B12.

How soon do you feel less tired after a B12 tablets? ›

Typically, our patients experience positive effects between 24-72 hours after the treatment.

Can I take sublingual B12 at night? ›

You can definitely opt for taking vitamin B12 supplements at night if that's what works best for you, although the natural energy-boosting abilities of vitamin B12 might be put to better use as you're starting the day.

Who should take sublingual B12? ›

It is used in people who do not get enough vitamin B12 from their diet or when their digestive tract does not absorb enough. Vitamin B12 plays an important role in maintaining the health of your nervous system and red blood cells.

What foods should be avoided if you have B12 deficiency? ›

“Some foods and drinks can interfere with vitamin B complex intake like alcohol, caffeine and processed foods, etc should be avoided completely,” Shah added.

Is 2000 mg of B12 too much to take daily? ›

The dose of 2000 micrograms of B12 is more than 800 times the recommended daily amount so, on the face of it, this dose seems too high, but as you increase the amount of B12 in your diet, less of a percentage will be absorbed. Before continuing the B12, I would recommend getting your B12 level tested with your doctor.

Can too much B12 cause neuropathy? ›

To much b-12 can aggravate the nerves. For me b-12 made things worse. Make sure you have your levels checked. To much b-12 can aggravate the nerves.

Is oral B12 as effective as injections? ›

Because oral supplements are absorbed less effectively, you need to take them far more frequently than you would need an injection. While it varies from case to case, it's usually recommended that you take oral supplements every day.

Does sublingual B12 give you energy? ›

So does vitamin B12 give you energy? While B12 doesn't directly provide energy, it does give the body the tools it needs to convert food molecules into energy. Getting the recommended daily amount of B12 can therefore help ensure that the body is able to make the energy it needs to do everything you need it to do.

Which form of vitamin B12 is best absorbed? ›

Methylcobalamin is the most bio-available type of Vitamin B12 which means the body absorbs it more easily. Naturally occurring, it is found in animal-based foods such as meat, fish, milk and eggs so Methylcobalamin B12 is readily available in many people's daily diets.

How long does it take sublingual B12 to work? ›

It may take a few weeks before your vitamin B12 levels and symptoms (such as extreme tiredness or lack of energy) start to improve.

What is the best oral form of B12? ›

The Best Type of Vitamin B12: Cyanocobalamin or Methylcobalamin? For prevention and treatment of vitamin B12 deficiency, cyanocobalamin in chewable, sublingual, or liquid forms (rather than in a multivitamin) is best under most circumstances.

Is it OK to take 1000 mcg of B12 a day? ›

Even the lowest doses in B12 supplements are many times the recommended dietary allowance. Doses up to 1,000 mcg, though unnecessary, aren't harmful.

Should B12 be taken with food or empty stomach? ›

Can You Take Vitamin B12 on an Empty Stomach? Vitamin B12 is water-soluble, which means you can take it with or without food. (Water-soluble vitamins don't require fat content to aid absorption.) If you have a sensitive stomach, however, we do recommend taking supplements with food.

Should I take B12 if I'm always tired? ›

Vitamin B12 is essential for the production of red blood cells and DNA. It is also essential for the functioning of the nervous system. When your body does not receive enough vitamin B12 you may feel fatigued and tired all the time. It can also lead to weakness.

Why do I get sleepy after taking B12? ›

While this may be true to an extent, it's essential to note that taking too much of specific vitamins can cause fatigue. For example, vitamins B6 and B12 play a key role in energy metabolism. However, taking large doses of these vitamins can also cause fatigue and other symptoms such as headaches, diarrhea, and nausea.


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