Sublingual Vitamin B12

Sublingual vitamin B12: B12 can be absorbed via the oral mucosa, which is referred to as a sublingual intake. What are the advantages and disadvantages?

Taking Sublingual Vitamin B12

In addition to the traditional route of absorption through the intestinal mucosa, vitamin B12 can also be absorbed through the oral mucosa. In theory, this can be advantageous if absorption via digestion is impaired, as it allows the B12 to bypass the intestine. 

Just how much vitamin B12 can be absorbed through the oral mucosa and how much is simply swallowed down into the intestine has not yet been researched. However, it is certain that sublingual absorption is at least as effective as a normal oral intake (1). 

Lozenges, Drops and Sprays

There are a number of vitamin B12 supplements which utilise sublingual absorption:

  • Vitamin B12 lozenges
  • Vitamin B12 drops and sprays
  • Vitamin B12 strips
  • Vitamin B12 toothpaste 

Drops and sprays are administered directly under the tongue, whereas strips and lozenges dissolve slowly under the tongue. These forms of supplements are particularly convenient for children and adults who have problems swallowing tablets and capsules.

Advantages of Sublingual Vitamin B12 Supplements

The various supplements with which vitamin B12 can be administered sublingually thus share the following advantages:

  • Absorption already takes place in the mouth
  • Intestinal absorption can be somewhat avoided
  • Easy to use and dose

Active Ingredients in Sublingual Vitamin B12 Supplements

There is a range of B12 active ingredients used in sublingual supplements to choose from. Here is a short overview:


No, artificial form

No, 4 conversion steps

Produces a small amount of cyanide, therefore not suitable for smokers or for detoxification. General effectiveness is proven, but worst absorption rate and long-term effectivity 




Very good absorption and effective for all purposes



No, 3 conversion steps

Common form of B12 in foods, good sustained release




Can be difficult to find supplements containing this form 


The exact vitamin B12 intake capacity via the oral mucosa is unknown, but is expected to be roughly equal to passive diffusion in the intestine. This equates to 1-2% of the full dose. In addition, a further maximum of 1.5 µg of the vitamin supplied is eventually absorbed with the help of the intrinsic factor on digestion. 

In order to be certain of covering the daily requirement, sublingual supplements should thus contain around 300-500 µg of B12.

For more information of vitamin B12 dosages, click here.

Disadvantages of Sublingual Vitamin B12 Supplements

Many sublingual products contain additives, such as flavourings and colourings, which are obviously not always desirable. An overview of the current additives used in various B12 supplement forms can be found in the following articles:

As a general rule, strips and lozenges contain the most additives, whilst drops and sprays tend to have less. Readers who want to use the more comfortable methods of absorption, but would prefer to avoid additives, are therefore best advised to use drops or sprays. 

Vitamin B12 Toothpaste

A very new form of sublingual supplement is vitamin B12 toothpaste. The best-known product by the company Sante provides around 3 µg of cyanocobalamin when used twice daily, and is therefore suitable as a B12 supplement. A study conducted by the German Institute for Alternative and Sustainable Diets (IFANE) found that a significant improvement in B12 levels was evident after just five weeks of use (2). At the expressed interest of customers, a fluoride-free product is also now available.


  1. Sharabi, A., Cohen, E., Sulkes, J. and Garty, M. (2003), Replacement therapy for vitamin B12 deficiency: comparison between the sublingual and oral route. British Journal of Clinical Pharmacology, 56: 635–638. doi: 10.1046/j.1365-2125.2003.01907.x