What to Look For in a Sublingual B123

Dr Jill Barat

Dr Jill Barat

PharmD, Compounding pharmacist
According to an estimate from the USDA, up to 2/5ths of the U.S. population may have low or marginal B12 levels. And, since this is a non-negotiable nutrient that helps build DNA, prevents certain forms of anemia, and keeps your nerves and blood cells healthy, it is necessary to get those levels up - ASAP. So, if your doctor has told you that you are part of this large group of low-B12-ers, you may be looking into what the best B12 supplement are. In this article we will cover what to look for in a sublingual B12 supplement, including a link to one of our favorite B12s that ticks all the boxes.

Sublingual lozenge vs. Capsule B12

To properly absorb B12 from a swallowed capsule, you need to have normal digestion, adequate stomach acid, and a protein necessary for B12 absorption in the intestines called “Intrinsic Factor” or “IF.”

In those that have perfectly functioning digestion, stomach acid levels, and Intrinsic Factor – you should be able to get about the same amount of B12 into your body by using a B12 capsule that you swallow or a B12 sublingual lozenge that dissolves under your tongue.

However, in those that have digestion issues, low stomach acid, or an Intrinsic Factor deficiency, you may be able to obtain better B12 levels by using a sublingual lozenge that dissolves under your tongue to bypass the stomach and intestines all together.

Since not everyone may know if they have optimal stomach acid levels or adequate Intrinsic Factor, we prefer to recommend a sublingual B12 supplement to all patients to err on the side of caution.

Methylcobalamin vs. Cyanocobalamin

Both Methylcobalamin and Cyanocobalamin are B12, but they differ mainly by having a different “side group.” Methylcobalamin has a methyl group, and Cyanocobalamin has a cyano group attached.

In your body, Methylcobalamin is the active form that performs all the needed B12 functions.

So, when you take Methylcobalamin, it is already in the active form and no extra steps need to be taken.

When you take Cyanocobalamin, the body converts it into Methylcobalamin to be active, but Cyanocobalamin itself is an inactive form.

This conversion step is called Methylation, and some people have genes that cause them to perform this Methylation step slower than usual.

For this reason, we prefer to stick to the already active Methylcobalamin formulation for supplementation purposes, and skip the extra conversion step necessary for Cyanocobalamin.

How much B12 should I take?

The National Institutes of Health recommend that adults get 2.4mcg of B12 daily.

If you find that you are not getting this amount from foods like meat and dairy, or you are a vegetarian or vegan, you are better off supplementing.

When supplementing B12, only a small portion of the vitamin (as low a 2%) is adequately absorbed, so the amounts you will take are much higher than what you will actually “get”.

For daily supplementation to help increase moderately low levels or for good B12 level maintenance, the American Pharmacists Association recommends 500mcg – 2,000mcg daily.

However, if you have a significant B12 deficiency, you may want to go with a larger dose of 5,000mcg daily for 4 weeks, before reducing your dose to 1,000-2,000mcg for maintenance.

Should you be taking sublingual lozenge

Look out for added ingredients

When choosing a good sublingual supplement, you want to look at the items listed underneath the nutrition label.

This is where you will find the inactive ingredients, like fillers, flavors, and colors.

We prefer sublingual supplements that don’t contain added sugar, artificial colors, or synthetic flavors.


A large portion of the U.S. may be deficient or have low-normal B12 levels.

B12 is a necessary nutrient for blood cells and nerve health that can cause long term damage if deficient.

Sublingual lozenges may have better absorption in those that have poor digestion or low intrinsic factor proteins.

Methylcobalamin is the active form of B12 and is preferred over Cyanocobalamin for supplementation.

For B12 supplementation, aim for 1,000-2,000mcg B12 daily to maintain good levels, and up to 5,000mcg daily short term to boost levels during deficiency.

Look for products that are allergen free and have natural colors and flavors.


Has your Provider already recommended that you use Sublingual lozenge or Capsule B12? Use the invite code THRACURMIN2019 to gain free access to Nutrivivo. Go to nutrivivo.com/create to sign-up with your free Patient account.

This article was written or reviewed by

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.

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