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Dietary supplement

Vitamin B12 (Methylcobalamin) Ingredients & Drug Interactions

by BulkSupplements.com

Vitamin B12 (Methylcobalamin) label
See full label image
Powder 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 Vitamin B12 (Methylcobalamin) 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

Vitamin B12 (Methylcobalamin) is a dietary supplement by BulkSupplements.com 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 B12. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Vitamin B12 (Methylcobalamin) by BulkSupplements.com

Ask about any prescription or over-the-counter medication and we check it for interactions with Vitamin B12 (Methylcobalamin) by BulkSupplements.com — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Vitamin B12 (Methylcobalamin) by BulkSupplements.com

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

Low disclosure
Ingredient Transparency · database check
Low

Most active ingredients don't disclose an individual amount — you can't tell how much of each you're getting.

Why this rating?
  • The label discloses an exact amount for 0 of its 1 active ingredient.

This product contains one active ingredient: vitamin B12 in the form of methylcobalamin, a form your body can use directly. There are no other inactive ingredients listed.

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

This product doesn't appear to be marketed for a specific use, so we graded Vitamin B12's overall clinical evidence instead.

Strong

Strong clinical evidence supports Vitamin B12 for:

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.
  • Since the label doesn't commit to one use, we graded the ingredient's overall clinical evidence instead.
  • On file: Imerslund-Grasbeck disease — rated "Effective" (Natural Medicines).
  • On file: Vitamin B12 deficiency — rated "Effective" (Natural Medicines).
  • On file: Cyanide poisoning — rated "Likely Effective" (Natural Medicines).
  • On file: Hyperhomocysteinemia — rated "Possibly Effective" (Natural Medicines).
  • On file: Postherpetic neuralgia — rated "Possibly Effective" (Natural Medicines).

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

For canker sores and postherpetic neuralgia (nerve pain after shingles), the evidence is weaker — the data rates it possibly effective, meaning some benefit is suggested but not firmly 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.

B12 is generally very well tolerated when taken by mouth. Your body excretes excess B12 in urine, so there's no established upper limit for how much is too much.

Allergic reactions are uncommon but possible — a small number of people have reported rashes or itching, and in rare cases someone with a cobalt allergy developed a skin reaction to oral methylcobalamin. If you develop a rash after starting B12, stop and talk to your pharmacist or doctor.

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.

The main medication to flag is metformin (Glucophage) — it can lower your B12 levels, which is why taking B12 alongside it may help. Check your exact medications with the tool below, though no other drug interactions are documented in our data for this ingredient.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFormula with limited ingredient disclosure with strong clinical evidence behind its ingredients' uses. Only minor medication interactions are documented, and safety information is well characterized.

B12 supplementation is a good fit if you have a documented deficiency, take metformin long-term, or have absorption issues. If you're pregnant or breastfeeding, B12 is important and considered safe at normal doses — follow your provider's guidance on how much you need.

If you take metformin, let your pharmacist know you're adding B12 so they can monitor your levels.

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 Oct 22, 2021.

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 Vitamin B12 (Methylcobalamin), straight from the product label.

Brand BulkSupplements.com
Barcode (UPC) X0001FYWVWV
Net contents 50 Gram(s); 1.76 Oz(s)
Market status On market
Date entered into DSLD Oct 22, 2021
DSLD ID 254413
Product type Vitamin
Supplement form Powder
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years)
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 Vitamin B12 (Methylcobalamin) by BulkSupplements.com, 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 Not Present
Maximum serving Sizes:
1 Not Present
UPC/BARCODE
X0001FYWVWV
IngredientAmount% DV
Vitamin B120 NP--

Other ingredients: None

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.
General Statements

Clean & pure bulk supplements

New - Bulksupplements Methyl B12 (Methylcobalamin) Pure Powder (50 grams)

Precautions

Warning: This product is not intended to diagnose, treat, cure, or prevent any disease.

Always consult a physician before taking any dietary supplement.

Keep out of reach of children.

This product is completely pure and should be used with extreme caution. Not intended for individual use and should be used by qualified professionals only.

Storage

Store in a dry, cool, dark place.

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

See for yourself

Vitamin B12 (Methylcobalamin) by BulkSupplements.com label

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

Vitamin B12 (Methylcobalamin) 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 Vitamin B12 (Methylcobalamin) by BulkSupplements.com

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

Serving size1 Not Present Dosage formPowder Amounts shown are per serving.

Vitamin B12

Interacts with
20 drugs
0 NP per serving Form: 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 B12 monograph & interactions

Other (inactive) ingredients: None. These complete the product’s ingredient list but are not active constituents.

Interaction report

Vitamin B12 (Methylcobalamin) by BulkSupplements.com Drug Interactions

Want to check YOUR meds against Vitamin B12 (Methylcobalamin)?

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 B12 20

Individual Drug Interactions

The ingredients in Vitamin B12 (Methylcobalamin) interact with 20 drugs. Click any drug to see the details.

1 of the 1 ingredient in Vitamin B12 (Methylcobalamin) interact with drugs. Each result below shows which ingredient is responsible. Vitamin B12

Each ingredient & the kinds of drugs it affects

For each ingredient in Vitamin B12 (Methylcobalamin) 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 B121 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 B12 full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Vitamin B12 (Methylcobalamin), from the product label.

BulkSupplements.com

See all BulkSupplements.com products
Name
BulkSupplements.com
Street Address
7511 Eastgate Rd
City
Henderson
State
NV
ZipCode
89011
Web Address
bulksupplements.com
Pharmacist Counseling Corner

Vitamin B12 (Methylcobalamin) by BulkSupplements.com: Common Questions

Does Vitamin B12 (Methylcobalamin) by BulkSupplements.com interact with any medications?
Yes. Based on its ingredients, Vitamin B12 (Methylcobalamin) 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?
Vitamin B12 (Methylcobalamin) 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.
Will this B12 supplement interfere with my metformin?
No — in fact, metformin can lower your B12 levels, so taking them together may actually help. Metformin interferes with B12 absorption in your digestive system over time, and B12 supplementation can help prevent a deficiency. Your pharmacist can monitor your levels if you're on metformin long-term.
Is B12 safe during pregnancy and breastfeeding?
Yes. B12 is needed during pregnancy and breastfeeding and is considered safe at normal recommended amounts. Follow your provider's advice on dosing for your situation.
What are the side effects of B12?
B12 taken by mouth is generally very well tolerated, and most people have no side effects. Allergic reactions like rash or itching are uncommon. In one rare case, someone with a cobalt allergy developed a skin reaction to oral methylcobalamin. Stop and contact your pharmacist or doctor if you develop a rash.
Can I take too much B12?
No — your body excretes excess B12 in urine, so there's no established upper limit. You can't overdose on it.
Does this product have fillers or other inactive ingredients?
No. This is pure vitamin B12 powder with no other inactive ingredients listed.

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

Not sure if Vitamin B12 (Methylcobalamin) 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.

Vitamin B12 (Methylcobalamin) label
Go deeper

The Full Monographs Behind Vitamin B12 (Methylcobalamin)’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

Vitamin B12 (Methylcobalamin)'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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