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Dietary supplement

B12 Methylcobalamin 3000 mcg Ingredients & Drug Interactions

by NutriCology

B12 Methylcobalamin 3000 mcg label
See full label image
Lozenge Category: Vitamin
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking B12 Methylcobalamin 3000 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: Moderate

B12 Methylcobalamin 3000 mcg is a dietary supplement by NutriCology with 3 active ingredients. Its ingredients are commonly taken for common cold and immune support, antioxidant support, skin health and collagen formation.Based on those ingredients, 266 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Vitamin C, Folic Acid, 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 B12 Methylcobalamin 3000 mcg by NutriCology

Ask about any prescription or over-the-counter medication and we check it for interactions with B12 Methylcobalamin 3000 mcg by NutriCology — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of B12 Methylcobalamin 3000 mcg by NutriCology

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 12, 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 3 of its 3 active ingredients.
  • “Folate” is listed as a grouped ingredient — the label gives one combined amount (666 mcg DFE) without saying how much of each component you get.

This lozenge contains 3 active ingredients. Methylcobalamin is the active form of vitamin B12, which your body needs for nerve function, red blood cell formation, and DNA synthesis.

Folic acid (a B vitamin) and vitamin C are included as supporting nutrients. The product also contains several inactive ingredients—fructose, mannitol, cellulose, and others—that serve as sweeteners, fillers, and binders to hold the lozenge together.

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: B12 and folic acid nutrient support.
  • We looked for evidence on: Anemia, Chronic fatigue syndrome (CFS), B12 deficiency, Folate deficiency, Pernicious anemia.
  • The strongest evidence on file: Vitamin B12 is rated "Effective" for Vitamin B12 deficiency (Natural Medicines).
  • Also on file: Folic Acid is rated "Effective" for Folate deficiency.
  • Also on file: Vitamin C is rated "Possibly Effective" for Anemia of chronic disease.

Vitamin B12 is effective for treating B12 deficiency and imerslund-grasbeck disease, a rare absorption disorder. It's also likely effective for cyanide poisoning and possibly effective for canker sores and postherpetic neuralgia (nerve pain after shingles).

Folic acid is effective for folate deficiency and likely effective for preventing neural tube birth defects and reducing methotrexate toxicity; it's possibly effective for depression and cognitive impairment. Vitamin C is effective for vitamin C deficiency and possibly effective for anemia of chronic disease, cataracts, and exercise-induced respiratory infections.

The combination is designed to provide B vitamin support, though the specific clinical benefit of taking all three together isn't established in our data.

The evidence, ingredient by ingredient Vitamin C Folic Acid 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 3 of the 3 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 3 of 3.
  • General safety write-ups exist for 3 of 3.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

All three ingredients are generally well tolerated at the doses typically found in supplements. Folic acid and vitamin C are considered safe at normal prenatal doses to support a healthy pregnancy, though high-dose vitamin C supplements should be avoided in late pregnancy or without medical guidance.

Vitamin B12 is safe during pregnancy and breastfeeding at recommended amounts. At higher doses, folic acid can occasionally cause abdominal cramps, diarrhea, rash, sleep disturbances, and nausea.

Vitamin C above 2 grams daily may cause heartburn, diarrhea, and kidney stones in susceptible people. Vitamin B12 is very safe with no upper limit, since excess is excreted in urine.

One important caution: folic acid can mask symptoms of B12 deficiency (pernicious anemia), delaying diagnosis and risking nerve damage—do not self-treat suspected anemia without medical evaluation.

Side effects, ingredient by ingredient Vitamin C Folic Acid Vitamin B12

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 3 of the 3 matched ingredients can interact with medications — Vitamin B12, Vitamin C, Folic Acid.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; cancer treatments.
  • For scale: 266 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.

Before you take this, check with your pharmacist if you're on seizure medications (phenobarbital, phenytoin, primidone), blood thinners like warfarin, methotrexate or other cancer drugs (capecitabine, 5-fluorouracil, antitumor antibiotics, or alkylating agents), oral contraceptives or hormone replacement therapy, thyroid hormone (levothyroxine), HIV medications (indinavir), or diabetes medications like metformin. Also check if you take aluminum-containing compounds or the antimalarial/antiparasitic pyrimethamine.

The folic acid and vitamin C in this product may interact with all of these.

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. Moderate medication interactions have been identified, and safety information is well characterized.

This is a reasonable choice if you're deficient in B12, folate, or vitamin C, or if you're looking for B vitamin support during pregnancy. However, if you take any seizure medications, chemotherapy drugs, blood thinners, thyroid hormone, diabetes medication, or oral contraceptives, check your specific drugs with the tool below before starting.

Talk to your pharmacist or doctor about whether this product makes sense for you and your medications.

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

Assessment coverage: 3 of 3 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Jan 22, 2022.

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 B12 Methylcobalamin 3000 mcg, straight from the product label.

Brand NutriCology
Barcode (UPC) 713947565609
Net contents 50 Vegetarian Lozenge(s)
Market status On market
Date entered into DSLD Jan 22, 2022
DSLD ID 258504
Product type Vitamin
Supplement form Lozenge
Dietary claims / uses Nutrient, All Other
Intended target group(s) Vegetarian, 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 B12 Methylcobalamin 3000 mcg by NutriCology, 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)
Servings per container
50
UPC/BARCODE
713947565609
IngredientAmount% DV
Folic Acid400 mcg--
Vitamin C50 mg56%
Folate666 mcg DFE166%
Vitamin B123000 mcg125000%

Other ingredients: Fructose, Mannitol, Cellulose, Stearic Acid, Croscarmellose Sodium, Magnesium Stearate, Silica, natural Cherry flavor, Raspberry flavor

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.
Formula

Conenzyme vitamin B12 in the form of methylcobalamin, with folic acid.

B12 Methylcobalamin 3000 mcg with Folic Acid

Suggested/Recommended/Usage/Directions

Suggested Use As a dietary supplement, adults place 1 lozenge daily under tongue 30 seconds before swallowing, or as directed by a healthcare professional. Do not exceed recommended dose.

Precautions

Do not exceed recommended dose.

Storage

Keep in a cool, dry place, tightly capped.

FDA Statement of Identity

Dietary Supplement

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

See for yourself

B12 Methylcobalamin 3000 mcg by NutriCology label

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

B12 Methylcobalamin 3000 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 B12 Methylcobalamin 3000 mcg by NutriCology

These are the 3 active ingredients this product is made of. Select any to open its full monograph.

Serving size1 Lozenge(s) Dosage formLozenge Servings per container50 Amounts shown are per serving.

Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.

Vitamin C

Interacts with
207 drugs
50 mg per serving Form: Ascorbic Acid

Vitamin C (ascorbic acid) is an essential nutrient your body needs but cannot make, so you must get it from food or supplements. It's important for im...

Vitamin C monograph & interactions

Folate

666 mcg DFE per serving

Vitamin B12

Interacts with
20 drugs
3000 mcg 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: Fructose, Mannitol, Cellulose, Stearic Acid, Croscarmellose Sodium, Magnesium Stearate, Silica, Natural Cherry flavor, Raspberry flavor. These complete the product’s ingredient list but are not active constituents.

Interaction report

B12 Methylcobalamin 3000 mcg by NutriCology Drug Interactions

Want to check YOUR meds against B12 Methylcobalamin 3000 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
266Drugs
141 Moderate 125 Minor

Ingredients driving the most interactions

Vitamin C 207
Folic Acid 40
Vitamin B12 20

Individual Drug Interactions

The ingredients in B12 Methylcobalamin 3000 mcg interact with 266 drugs. Click any drug to see the details.

3 of the 3 ingredients in B12 Methylcobalamin 3000 mcg interact with drugs. Each result below shows which ingredient is responsible. Vitamin C Folic Acid Vitamin B12

Each ingredient & the kinds of drugs it affects

For each ingredient in B12 Methylcobalamin 3000 mcg with known interactions, here are the types of medications they can affect. Open any type for the detail — or search your exact drug in the checker above.

Vitamin C13 drug types · 207 drugs

Alkylating Agents

Theoretically, antioxidant effects of vitamin C might reduce the effectiveness of alkylating agents.
The use of antioxidants like vitamin C during chemotherapy is controversial. There is concern that antioxidants could reduce the activity of chemotherapy drugs that generate free radicals, such as cyclophosphamide, chlorambucil, carmustine, busulfan, and thiotepa. In contrast, some researchers theorize that antioxidants might make chemotherapy more effective by reducing oxidative stress that could interfere with apoptosis (cell death) of cancer cells. More evidence is needed to determine what effect, if any, antioxidants such as vitamin C have on chemotherapy.

Likelihood Possible Evidence D
Aluminum

Vitamin C can increase the amount of aluminum absorbed from aluminum compounds.
Research in animals and humans shows that vitamin C increases aluminum absorption, theoretically by chelating aluminum and keeping it in solution where it is available for absorption. In people with normal renal function, urinary excretion of aluminum will likely increase, making aluminum retention and toxicity unlikely. Patients with renal failure who take aluminum-containing compounds such as phosphate binders should avoid vitamin C supplements in doses above the recommended dietary allowances.

Likelihood Probable Evidence B
Antitumor Antibiotics

Theoretically, the antioxidant effects of vitamin C might reduce the effectiveness of antitumor antibiotics.
The use of antioxidants like vitamin C during chemotherapy is controversial. There is concern that antioxidants could reduce the activity of chemotherapy drugs which generate free radicals, such as doxorubicin. In contrast, some researchers theorize that antioxidants might make chemotherapy more effective by reducing oxidative stress that could interfere with apoptosis (cell death) of cancer cells. More evidence is needed to determine what effects, if any, antioxidants such as vitamin C have on chemotherapy.

Likelihood Possible Evidence D
Estrogens

Vitamin C might increase blood levels of estrogens.
Increases in plasma estrogen levels of up to 55% occur under some circumstances when vitamin C is taken concurrently with oral contraceptives or hormone replacement therapy, including topical products. It is suggested that vitamin C prevents oxidation of estrogen in the tissues, regenerates oxidized estrogen, and reduces sulfate conjugation of estrogen in the gut wall. When tissue levels of vitamin C are high, these processes are already maximized and supplemental vitamin C does not have any effect on estrogen levels. Increases in plasma estrogen levels may occur when patients who are deficient in vitamin C take supplements. Monitor these patients for estrogen-related side effects.

Likelihood Probable Evidence B
Fluphenazine (Prolixin)

Theoretically, vitamin C might decrease levels of fluphenazine.
In one patient there was a clinically significant decrease in fluphenazine levels when vitamin C (500 mg twice daily) was started. The mechanism is not known, and there is no further data to confirm this interaction.

Likelihood Possible Evidence D
Indinavir (Crixivan)

Vitamin C can modestly reduce indinavir levels.
One pharmacokinetic study shows that taking vitamin C 1 gram orally once daily along with indinavir 800 mg orally three times daily reduces the area under the concentration-time curve of indinavir by 14%. The mechanism of this interaction is unknown, but it is unlikely to be clinically significant in most patients. The effect of higher doses of vitamin C on indinavir levels is unknown.

Likelihood Probable Evidence B
Levothyroxine (Synthroid, Others)

Vitamin C can increase levothyroxine absorption.
Two clinical studies in adults with poorly controlled hypothyroidism show that swallowing levothyroxine with a glass of water containing vitamin C 500-1000 mg in solution reduces thyroid stimulating hormone (TSH) levels and increases thyroxine (T4) levels when compared with taking levothyroxine alone. This suggests that vitamin C increases the oral absorption of levothyroxine, possibly due to a reduction in pH.

Likelihood Probable Evidence B
Warfarin (Coumadin)

High-dose vitamin C might reduce the levels and effectiveness of warfarin.
Vitamin C in high doses may cause diarrhea and possibly reduce warfarin absorption. There are reports of two people who took up to 16 grams daily of vitamin C and had a reduction in prothrombin time. Lower doses of 5-10 grams daily can also reduce warfarin absorption. In many cases, this does not seem to be clinically significant. However, a case of warfarin resistance has been reported for a patient who took vitamin C 500 mg twice daily. Cessation of vitamin C supplementation resulted in a rapid increase in international normalized ratio (INR). Tell patients taking warfarin to avoid taking vitamin C in excessively high doses (greater than 10 grams daily). Lower doses may be safe, but the anticoagulation activity of warfarin should be monitored. Patients who are stabilized on warfarin while taking vitamin C should avoid adjusting vitamin C dosage to prevent the possibility of warfarin resistance.

Likelihood Possible Evidence D
Acetaminophen (Tylenol, Others)

High-dose vitamin C might slightly prolong the clearance of acetaminophen.
A small pharmacokinetic study in healthy volunteers shows that taking high-dose vitamin C (3 grams) 1.5 hours after taking acetaminophen 1 gram slightly increases the apparent half-life of acetaminophen from around 2.3 hours to 3.1 hours. Ascorbic acid competitively inhibits sulfate conjugation of acetaminophen. However, to compensate, elimination of acetaminophen glucuronide and unconjugated acetaminophen increases. This effect is not likely to be clinically significant.

Likelihood Probable Evidence B
Aspirin

Acidification of the urine by vitamin C might increase aspirin levels.
It has been suggested that acidification of the urine by vitamin C could increase reabsorption of salicylates by the renal tubules, and increase plasma salicylate levels. However, short-term use of up to 6 grams daily of vitamin C does not seem to affect urinary pH or salicylate excretion, suggesting this interaction is not clinically significant.

Likelihood Possible Evidence B
Choline Magnesium Trisalicylate (Trilisate)

Acidification of the urine by vitamin C might increase choline magnesium trisalicylate levels.
It has been suggested that acidification of the urine by vitamin C could increase reabsorption of salicylates by the renal tubules, and increase plasma salicylate levels. However, short-term use of up to 6 grams daily of vitamin C does not seem to affect urinary pH or salicylate excretion, suggesting this interaction probably is not clinically significant.

Likelihood Possible Evidence B
Niacin

Vitamin C might decrease the beneficial effects of niacin on high-density lipoprotein (HDL) cholesterol levels.
A combination of niacin and simvastatin (Zocor) effectively raises HDL cholesterol levels in patients with coronary disease and low HDL levels. Clinical research shows that taking a combination of antioxidants (vitamin C, vitamin E, beta-carotene, and selenium) along with niacin and simvastatin (Zocor) attenuates this rise in HDL, specifically the HDL-2 and apolipoprotein A1 fractions, by more than 50% in patients with coronary disease. It is not known whether this adverse effect is due to a single antioxidant such as vitamin C, or to the combination. It also is not known whether it will occur in other patient populations.

Likelihood Possible Evidence A
Salsalate (Disalcid)

Acidification of the urine by vitamin C might increase salsalate levels.
It has been suggested that acidification of the urine by vitamin C could increase reabsorption of salicylates by the renal tubules, and increase plasma salicylate levels. However, short-term use of up to 6 grams/day vitamin C does not seem to affect urinary pH or salicylate excretion, suggesting this interaction probably is not clinically significant.

Likelihood Possible Evidence B
Vitamin C full monograph & interactions

Folic Acid7 drug types · 40 drugs

5-Fluorouracil

Theoretically, high doses of folic acid might increase the toxicity of 5-fluorouracil.
Increases in gastrointestinal side effects of 5-fluorouracil, such as stomatitis and diarrhea, have been described in two clinical studies when leucovorin, a form of folic acid, was administered with 5-fluorouracil.

Likelihood Possible Evidence D
Capecitabine (Xeloda)

Use of high-dose folic acid might contribute to capecitabine toxicity.
Clinical research suggests that higher serum folate levels are associated with an increased risk for moderate or severe toxicity during capecitabine-based treatment for colorectal cancer. Additionally, in one case report, taking folic acid 15 mg daily might have contributed to increased toxicity, including severe diarrhea, vomiting, edema, hand-foot syndrome, and eventually death, in a patient prescribed capecitabine.

Likelihood Possible Evidence D
Methotrexate (Trexall, Others)

Folic acid might reduce the efficacy of methotrexate as a cancer treatment when given concurrently.
Methotrexate exerts its cytotoxic effects by preventing conversion of folic acid to the active form needed by cells. There is some evidence that folic acid supplements reduce the efficacy of methotrexate in the treatment of acute lymphoblastic leukemia, and theoretically they could reduce its efficacy in the treatment of other cancers. Advise cancer patients to consult their oncologist before using folic acid supplements. In patients treated with long-term, low-dose methotrexate for rheumatoid arthritis (RA) or psoriasis, folic acid supplements can reduce the incidence of side effects, without reducing efficacy.

Likelihood Probable Evidence B
Phenobarbital (Luminal)

Folic acid might have antagonistic effects on phenobarbital and increase the risk for seizures.
Folic acid can have direct convulsant activity in some people, reversing the effects of phenobarbital and worsening seizure control. Monitor closely for increased seizure activity.

Likelihood Probable Evidence B
Phenytoin (Dilantin)

Folic acid might reduce serum levels of phenytoin in some patients.
Folic acid may be a cofactor in phenytoin metabolism. Folic acid, in doses of 1 mg daily or more, can reduce serum levels of phenytoin in some patients. Increases in seizure frequency have been reported. If folic acid supplements are added to established phenytoin therapy, monitor serum phenytoin levels closely. If phenytoin and folic acid are started at the same time and continued together, adverse changes in phenytoin pharmacokinetics are avoided. Note that phenytoin also reduces serum folate levels.

Likelihood Probable Evidence B
Primidone (Mysoline)

Folic acid might have antagonistic effects on primidone and increase the risk for seizures.
Folic acid can have direct convulsant activity in some people, reversing the effects of primidone and worsening seizure control. Monitor closely for increased seizure activity. Note that primidone also reduces serum folate levels.

Likelihood Probable Evidence B
Pyrimethamine (Daraprim)

Folic acid might antagonize the effects of pyrimethamine.
Folic acid can antagonize the antiparasitic effects of pyrimethamine against toxoplasmosis and Pneumocystis carinii pneumonia. Folic acid doesn't antagonize the effects of pyrimethamine in the treatment of malaria, because malarial parasites cannot use exogenous folic acid. Use folinic acid as an alternative to folic acid when indicated.

Likelihood Probable Evidence D
Folic Acid full monograph & interactions

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 B12 Methylcobalamin 3000 mcg, from the product label.

NutriCology

See all NutriCology products
Name
NutriCology
City
South Salt Lake
State
UT
ZipCode
84115
Phone Number
800.545.9960
Web Address
www.nutricology.com
Pharmacist Counseling Corner

B12 Methylcobalamin 3000 mcg by NutriCology: Common Questions

Does B12 Methylcobalamin 3000 mcg by NutriCology interact with any medications?
Yes. Based on its ingredients, B12 Methylcobalamin 3000 mcg has a known interaction with 266 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
B12 Methylcobalamin 3000 mcg contains 3 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is 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.
What is methylcobalamin, and is it better than other forms of B12?
Methylcobalamin is the active form of vitamin B12 your body uses directly. The facts we hold don't compare it to other B12 forms, so I can't say whether it's better—but it's an effective choice for treating B12 deficiency and supporting nerve function.
Can I take this while I'm pregnant?
Vitamin B12 and folic acid are both considered safe at recommended doses during pregnancy and actually help prevent birth defects. Vitamin C at normal amounts is also safe, but avoid high-dose vitamin C supplements in late pregnancy without your doctor's guidance. Always talk with your obstetrician or pharmacist about what's right for you.
Will this cause side effects?
At normal doses, all three ingredients are well tolerated. Folic acid at higher doses can cause abdominal cramps, diarrhea, rash, or sleep disturbances. Vitamin C above 2 grams daily may cause heartburn or diarrhea. Vitamin B12 is very safe with no known upper limit.
Does this help with energy or fatigue?
Vitamin B12 is essential for energy metabolism and nerve function, so correcting a deficiency can help with fatigue. The facts we hold don't establish whether this product boosts energy in people without a deficiency.
Can I take this if I'm on metformin for diabetes?
Metformin can lower B12 levels with long-term use, so this product may actually help. However, check with your pharmacist or doctor—they can monitor your B12 and folic acid levels if you're on metformin, especially because folic acid can mask B12 deficiency.
Is it safe to take this with my vitamin supplements?
The interactions listed on this page cover medications, not other supplements. Talk to your pharmacist about any other vitamins or supplements you're taking—they can check for overlaps or conflicts.

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

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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.

B12 Methylcobalamin 3000 mcg label
Go deeper

The Full Monographs Behind B12 Methylcobalamin 3000 mcg’s Ingredients

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

Herb & supplement monograph

Vitamin C

Interacts with 207 drugs

Vitamin C (ascorbic acid) is an essential nutrient your body needs but cannot make, so you must get it from food or supplements. It's important for immune function, collagen, and acts as an...

Read the full Vitamin C monograph → Herb & supplement monograph

Folic Acid

Interacts with 40 drugs

Folic acid is the man-made form of vitamin B9 and is one of the most well-studied supplements, especially for preventing serious birth defects when taken before and during early pregnancy. I...

Read the full Folic Acid monograph → 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

B12 Methylcobalamin 3000 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 137 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.

Folic Acid 56 references
  1. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
  2. Duhra P. Treatment of gastrointestinal symptoms associated with methotrexate therapy for psoriasis. J Am Acad Dermatol 1993;28:466-9. PubMed
  3. Morgan SL, Baggott JE, Vaughn WH, et al. Supplementation with folic acid during methotrexate therapy for rheumatoid arthritis. A double-blind, placebo-controlled trial. Ann Intern Med 1994;121:833-41. PubMed
  4. Froscher W, Maier V, Laage M, et al. Folate deficiency, anticonvulsant drugs, and psychiatric morbidity. Clin Neuropharmacol 1995;18:165-82. PubMed
  5. Lewis DP, Van Dyke DC, Willhite LA, et al. Phenytoin-folic acid interaction. Ann Pharmacother 1995;29:726-35. PubMed
  6. Berg MJ, Stumbo PJ, Chenard CA, et al. Folic acid improves phenytoin pharmacokinetics. J Am Diet Assoc 1995;95:352-6. PubMed
  7. Berg MJ, Fincham RW, Ebert BE, et al. Phenytoin pharmacokinetics: Before and after folic acid administration. Epilepsia 1992;33:712-20. PubMed
  8. Shafer RB, Nuttall FQ. Calcium and folic acid absorption in patients taking anticonvulsant drugs. J Clin Endocrinol Metab 1975;41:1125-9. PubMed
  9. Leeb BF, Witzmann G, Ogris E, et al. Folic acid and cyanocobalamin levels in serum and erythrocytes during low-dose methotrexate therapy of rheumatoid arthritis and psoriatic arthritis patients. Clin Exp Rheumatol 1995;13:459-63.
  10. Morgan SL, Baggott JE, Lee JY, Alarcón GS. Folic acid supplementation prevents deficient blood folate levels and hyperhomocysteinemia during longterm, low dose methotrexate therapy for rheumatoid arthritis: implications for cardiovascular disease preventi
  11. Dijkmans BA. Folate supplementation and methotrexate. Br J Rheumatol 1995;34:1172-4. PubMed
  12. Segal S, Kaminski S. Drug-nutrient interactions. American Druggist 1996 Jul;42-8.
  13. Lambie DG, Johnson RH. Drugs and folate metabolism. Drugs 1985;30:145-55. PubMed
  14. Amer College of Rheumatology ad hoc committee on clinical guidelines. Guidelines for monitoring drug therapy in rheumatoid arthritis. Arthritis Rheum 1996;39:723-31. DOI
  15. Suitor CW, Bailey LB. Dietary folate equivalents: interpretation and application. J Am Diet Assoc 2000;100:88-94. PubMed
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Vitamin B12 30 references
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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.

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