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Dietary supplement

B-12 2,000 mcg Ingredients & Drug Interactions

by NOW

B-12 2,000 mcg label
See full label image
Lozenge Category: Vitamin
Most serious interaction: Minor
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking B-12 2,000 mcg against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Minor

B-12 2,000 mcg is a dietary supplement by NOW with 1 active ingredient. Its ingredients are commonly taken for treating or preventing b12 deficiency, pernicious anemia, low energy and fatigue.Based on those ingredients, 20 medications have a known interaction with it, the most serious rated minor. The ingredients most likely to interact are Vitamin B-12. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against B-12 2,000 mcg by NOW

Ask about any prescription or over-the-counter medication and we check it for interactions with B-12 2,000 mcg by NOW — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of B-12 2,000 mcg by NOW

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

This product contains one active ingredient: vitamin B-12 at 2,000 micrograms per lozenge. The lozenge also contains inactive ingredients including fructose, microcrystalline cellulose, sorbitol, natural flavors, citric acid, magnesium stearate, and soy lecithin.

Does it work?

Strong evidence
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Strong

Clinical evidence supports at least one of this product's ingredients for its stated purpose.

Why this rating?
  • The label markets this product for: nervous system health and energy production.
  • We looked for evidence on: Vitamin B12 deficiency, Peripheral neuropathy, Chemotherapy-induced peripheral neuropathy, Diabetic neuropathy, Fatigue, Cognitive function — and 4 related terms.
  • The strongest evidence on file: Vitamin B12 is rated "Effective" for Vitamin B12 deficiency (Natural Medicines).
  • Also on file: Vitamin B12 is rated "Possibly Effective" for Hyperhomocysteinemia.
  • Also on file: Vitamin B12 is rated "Possibly Ineffective" for Age-related cognitive decline, Alzheimer disease.

Vitamin B-12 is effective for treating B12 deficiency and Imerslund-Grasbeck disease (a rare genetic disorder affecting B12 absorption). It's also likely effective for cyanide poisoning.

The evidence suggests it may help with canker sores and postherpetic neuralgia (nerve pain after shingles), though the data for these uses is less established.

The evidence, ingredient by ingredient Vitamin B12

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

B-12 is generally very well tolerated. Your body removes excess B12 in the urine, so there's no established upper limit for daily intake.

When taken by mouth as a supplement, it rarely causes side effects — though allergic reactions like rash or itching are possible, especially in people with a cobalt allergy. B12 is considered safe during pregnancy and breastfeeding at recommended amounts; follow your healthcare provider's guidance on dosing.

Side effects, ingredient by ingredient Vitamin B12

Meds to double-check

Minor interactions only
Known Interaction Concern · database check
Minor only

Only Minor-severity interactions are documented for these ingredients.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Vitamin B12.
  • The most serious interaction on file is rated Minor.
  • For scale: 20 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

If you take metformin (Glucophage) for diabetes, let your pharmacist know — B-12 can help offset the B12-lowering effect of that medication. No other medication interactions are documented for the ingredients we could check.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with clinical evidence supporting its stated purpose. Only minor medication interactions are documented, and safety information is well characterized.

B-12 supplementation works well for correcting deficiency and is very safe for most people. If you take metformin for diabetes, this supplement may help prevent the B12 deficiency that metformin can cause.

Check your other medications with the tool on this page before starting. If you have questions about the right dose for you, ask your pharmacist or doctor.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Jul 24, 2019.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about B-12 2,000 mcg, straight from the product label.

Brand NOW
Barcode (UPC) 733739004598
Net contents 100 Lozenge(s)
Market status On market
Date entered into DSLD Jul 24, 2019
DSLD ID 204870
Product type Vitamin
Supplement form Lozenge
Dietary claims / uses Nutrient, All Other, Structure/Function
Intended target group(s) Vegan, Vegetarian, Adult (18 - 50 Years), Kosher, Gluten Free, Dairy Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for B-12 2,000 mcg by NOW, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
1 Lozenge(s)
Maximum serving Sizes:
1 Lozenge(s)
UPC/BARCODE
733739004598
IngredientAmount% DV
Vitamin B-122 mg83333%

Other ingredients: Fructose, Microcrystalline Cellulose, Sorbitol, Natural Flavors, Citric Acid, Magnesium Stearate, Soy Lecithin

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Suggested/Recommended/Usage/Directions

Suggested Usage: Take 1 lozenge daily. Chew lozenge or hold in mouth until dissolved and swallow.

Formula

Vitamin B-12 (Cobalamin) is a water soluble vitamin necessary for the maintenance of a healthy nervous system and for the production of energy from fats and proteins. Vitamin B-12 is also essential for the synthesis of DNA during cell division and therefore is especially important for rapidly multiplying cells, such as blood cells. While B-12 is stored in the liver, dietary sources are of animal origin only (meat and dairy). Therefore, supplementation with B-12 may be especially important for strict vegetarians. This product provides Vitamin B-12 in three forms, including the two readily available and activated co-enzyme forms, Methylcobalamin and Dibencozide.

3 Forms of B-12, including Co-Enzyme Forms

Triangle K

FDA Disclaimer Statement

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.

Precautions

Caution: For adults only.

Consult physician if pregnant/nursing, taking medication, or have a medical condition.

Keep out of reach of children.

Not manufactured with wheat, gluten, milk, egg, fish, shellfish or tree nut ingredients. Produced in a GMP facility that processes other ingredients containing these allergens.

General Statements

Nervous System Health Essential for Energy Production

Vitamins

Family owned since 1968.

Natural color variation may occur in this product.

FDA Statement of Identity

A Dietary Supplement

Formulation

Vegetarian/Vegan

Not manufactured with wheat, gluten, milk, egg, fish, shellfish or tree nut ingredients.

Seals/Symbols

Triangle K

GMP Quality Assured

Storage

Store in a cool, dry place after opening.

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

B-12 2,000 mcg by NOW label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

B-12 2,000 mcg label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in B-12 2,000 mcg by NOW

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size1 Lozenge(s) Dosage formLozenge Amounts shown are per serving.

Vitamin B-12

Interacts with
20 drugs
2 mg per serving Form: Cyanocobalamin, Dibencozide, Methylcobalamin

Vitamin B12 (cobalamin) is an essential nutrient your body needs to make red blood cells, keep nerves healthy, and support DNA. Supplements are very h...

Vitamin B-12 monograph & interactions

Other (inactive) ingredients: Fructose, Microcrystalline Cellulose, Sorbitol, Natural Flavors, Citric Acid, Magnesium Stearate, Soy Lecithin. These complete the product’s ingredient list but are not active constituents.

Interaction report

B-12 2,000 mcg by NOW Drug Interactions

Want to check YOUR meds against B-12 2,000 mcg?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
20Drugs
20 Minor

Ingredients driving the most interactions

Vitamin B-12 20

Individual Drug Interactions

The ingredients in B-12 2,000 mcg interact with 20 drugs. Click any drug to see the details.

1 of the 1 ingredient in B-12 2,000 mcg interact with drugs. Each result below shows which ingredient is responsible. Vitamin B-12

Each ingredient & the kinds of drugs it affects

For each ingredient in B-12 2,000 mcg with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

Vitamin B-121 drug type · 20 drugs

Metformin (Glucophage)

Metformin, a common medication used to manage type 2 diabetes, has been associated with lower vitamin B12 levels in some individuals. Prolonged use of metformin can interfere with the absorption of B12 in the digestive system, potentially leading to a deficiency in this essential vitamin.

Likelihood Possible Evidence A
Vitamin B-12 full monograph & interactions
The maker

Brand information

Manufacturer and brand details for B-12 2,000 mcg, from the product label.

NOW

See all NOW products
Name
NOW Foods
Street Address
395 S. Glen Ellyn Rd.
City
Bloomingdale
State
IL
ZipCode
60108
Web Address
nowfoods.com
Pharmacist Counseling Corner

B-12 2,000 mcg by NOW: Common Questions

Does B-12 2,000 mcg by NOW interact with any medications?
Yes. Based on its ingredients, B-12 2,000 mcg has a known interaction with 20 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
B-12 2,000 mcg contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
I take metformin for diabetes. Is B-12 safe for me?
Yes — metformin can lower B12 levels, and this supplement may help prevent that deficiency. It's a minor interaction, meaning the supplement and drug don't stop each other from working. Just mention both to your pharmacist so they can make sure you're taking the right amount.
Can I take too much B-12?
No. Your body removes extra B-12 in the urine, so there's no upper limit set for daily intake. You can't overdose on it.
Is B-12 safe if I'm pregnant or breastfeeding?
Yes, at recommended amounts. B-12 is actually needed during pregnancy and breastfeeding. Follow your provider's advice on dosing for your situation.
What is B-12 used for?
It treats and prevents B-12 deficiency, which can cause fatigue, weakness, and nerve problems. It's also effective for a rare inherited disorder called Imerslund-Grasbeck disease and likely effective for cyanide poisoning. Some evidence suggests it may help with canker sores and nerve pain after shingles.
What are the side effects of B-12 lozenges?
Serious side effects are very rare. Most people tolerate it well. Allergic reactions — like rash or itching — can happen, especially if you have a sensitivity to cobalt. If you notice a rash or itching after starting, stop and call your pharmacist.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Not sure if B-12 2,000 mcg is safe with your meds?

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Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

B-12 2,000 mcg label
Go deeper

The Full Monographs Behind B-12 2,000 mcg’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Vitamin B12

Interacts with 20 drugs

Vitamin B12 (cobalamin) is an essential nutrient your body needs to make red blood cells, keep nerves healthy, and support DNA. Supplements are very helpful for people who are deficient — su...

Read the full Vitamin B12 monograph →
Sources

Sources & How We Checked

B-12 2,000 mcg's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 30 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Vitamin B12 30 references
  1. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline (2000). Washington, DC: National Academy Press, 2000. Available at: http://b
  2. Hartman TJ, Woodson K, Stolzenberg-Solomon R, et al. Association of the B-vitamins pyridoxal 5'-phosphate (B6), B12, and folate with lung cancer risk in older men. Am J Epidemiol 2001;153:688-94.. DOI
  3. Jansen T, Romiti R, Kreuter A, Altmeyer P. Rosacea fulminans triggered by high-dose vitamins B6 and B12. J Eur Acad Dermatol Venereol 2001;15:484-5..
  4. Lange H, Suryapranata H, De Luca G, et al. Folate therapy and in-stent restenosis after coronary stenting. N Engl J Med 2004;350:2673-81. PubMed
  5. Collin, S. M., Metcalfe, C., Refsum, H., Lewis, S. J., Zuccolo, L., Smith, G. D., Chen, L., Harris, R., Davis, M., Marsden, G., Johnston, C., Lane, J. A., Ebbing, M., Bonaa, K. H., Nygard, O., Ueland, P. M., Grau, M. V., Baron, J. A., Donovan, J. L., Nea
  6. Geissbuhler, P., Mermillod, B., and Rapin, C. H. Elevated serum vitamin B12 levels associated with CRP as a predictive factor of mortality in palliative care cancer patients: a prospective study over five years. J.Pain Symptom.Manage. 2000;20(2):93-103. PubMed
  7. Salles, N., Herrmann, F., Sakbani, K., Rapin, C. H., and Sieber, C. High vitamin B12 level: a strong predictor of mortality in elderly inpatients. J Am Geriatr.Soc 2005;53(5):917-918.
  8. Looker, H. C., Fagot-Campagna, A., Gunter, E. W., Pfeiffer, C. M., Sievers, M. L., Bennett, P. H., Nelson, R. G., Hanson, R. L., and Knowler, W. C. Homocysteine and vitamin B(12) concentrations and mortality rates in type 2 diabetes. Diabetes Metab Res R
  9. Uhl, W., Nolting, A., Golor, G., Rost, K. L., and Kovar, A. Safety of hydroxocobalamin in healthy volunteers in a randomized, placebo-controlled study. Clin Toxicol (Phila) 2006;44 Suppl 1:17-28. PubMed
  10. Borron, S. W., Baud, F. J., Barriot, P., Imbert, M., and Bismuth, C. Prospective study of hydroxocobalamin for acute cyanide poisoning in smoke inhalation. Ann Emerg.Med 2007;49(6):794-801, 801. PubMed
  11. Borron, S. W., Baud, F. J., Megarbane, B., and Bismuth, C. Hydroxocobalamin for severe acute cyanide poisoning by ingestion or inhalation. Am J Emerg.Med 2007;25(5):551-558. PubMed
  12. Lewis, J. G. Gout, Steatorrhoea, and Megaloblastic Anaemia. Ann Rheum.Dis 1962;21(3):284-286. PubMed
  13. Tal, S., Shavit, Y., Stern, F., and Malnick, S. Association between vitamin B12 levels and mortality in hospitalized older adults. J Am Geriatr.Soc 2010;58(3):523-526. PubMed
  14. Baztan, J. J., Gavidia, J. J., Gomez-Pavon, J., Esteve, A., and Ruiperez, I. High vitamin B12 levels and in-hospital mortality. J Am Geriatr.Soc 2010;58(11):2237-2238. PubMed
  15. Omboni, E., Checchini, M., and Longoni, F. [Hypopotassemia and megaloblastic anemia. Presentation of a case]. Minerva Med 8-31-1987;78(16):1255-1257.
  16. Aalfs As, Scholvinck LH, Horvath B. Acneiform eruption in a 5-year old due to vitamin B12 supplementation. Eur J Dermatol 2013;23(5):726-7. PubMed
  17. Balta I, Ozuguz P. Vitamin B12-induced acneiform eruption. Cutan Ocul Toxicol 2014;33(2):94-5. PubMed
  18. Carman KB, Belgemen T, Yis U. Involuntary movements misdiagnosed as seizure during vitamin B12 treatment. Pediatr Emerg Care 2013;29(11):1223-4. PubMed
  19. Djuric V, Bogic M, Popadic AP, et al. Anaphylactic reaction to hydroxycobalamin with tolerance to cyanocobalamin. Ann Allergy Asthma Immunol 2012;108(3):207-8. PubMed
  20. Kartel O, Gulec M, Demirel F, et al. Vitamin B12 allergy and successful desensitization with cyanocobalamin: A case report. Allergol Immunopath (Madr) 2012;40(5):324-5.
  21. Patiroglu T, Unal E, Yildirim S. Infantile tremor syndrome associated with cobalamin therapy: A case report. Clin Neurol Neurosurg 2013;115(9):1903-5. PubMed
  22. Schulte S, Barkema LW, Kardaun SH. Long-lasting atypical acneiform eruption with prominent comedones induced by hydroxocobalamin (vitamin B12). J Dtsch Dermatol Ges 2014;12(6):502-3.
  23. Zanus C, Alberini E, Costa P, et al. Involuntary movements after correction of vitamin B12 deficiency: A video-case report. Epileptic Disord 2012;14(2):174-80. PubMed
  24. Fanidi A, Carreras-Torres R, Larose TL, et al. Is high vitamin B12 status a cause of lung cancer? Int J Cancer. 2019 Sep 15;145(6):1499-1503. PubMed
  25. Fujita Y, Mizukami T, Maya Y, et al. Vitamin B12 allergy manifesting as lymphomatoid contact dermatitis. Eur J Dermatol. 2020;30(3):304-305. PubMed
  26. Dépret F, Hoffmann C, Daoud L, et al. Association between hydroxocobalamin administration and acute kidney injury after smoke inhalation: a multicenter retrospective study. Crit Care. 2019;23(1):421. PubMed
  27. Khairan P, Sobue T, Eshak ES, et al. Association of dietary intakes of vitamin B12, vitamin B6, folate, and methionine with the risk of esophageal cancer: the Japan Public Health Center-based (JPHC) prospective study. BMC Cancer 2021;21(1):982. PubMed
  28. Evans J, Pandya A, Ding Y, Qunibi WY. Hydroxocobalamin-Induced Oxalate Nephropathy in a Patient With Smoke Inhalation. Kidney Int Rep 2021;6(8):2228-2231. PubMed
  29. Lacombe V, Chabrun F, Lacout C, et al. Persistent elevation of plasma vitamin B12 is strongly associated with solid cancer. Sci Rep 2021;11(1):13361. PubMed
  30. Pegalajar-García MD, Cebolla-Verdugo M, Prados-Carmona Á, Llamas-Segura C, Navarro-Triviño FJ. Systemic allergic dermatitis to cobalt present in cyanocobalamin supplementation. Contact Dermatitis 2023;89(3):203-205. PubMed

See these in context on the Vitamin B12 monograph →

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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