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Dietary supplement

Vitamin B-2 400 mg Ingredients & Drug Interactions

by Best Naturals

Vitamin B-2 400 mg label
See full label image
Capsule 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 Vitamin B-2 400 mg 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

Vitamin B-2 400 mg is a dietary supplement by Best Naturals with 1 active ingredient. Its ingredients are commonly taken for riboflavin deficiency, migraine prevention, general energy and metabolism support.Based on those ingredients, 20 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Riboflavin. 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 B-2 400 mg by Best Naturals

Ask about any prescription or over-the-counter medication and we check it for interactions with Vitamin B-2 400 mg by Best Naturals — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Vitamin B-2 400 mg by Best Naturals

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: riboflavin (also called vitamin B-2) at 400 mg per capsule. Riboflavin is a B vitamin that your body uses to convert food into energy and support cell growth.

The remaining ingredients—capsule material, magnesium stearate, and silicon dioxide—are inactive components that help form and preserve the supplement.

Does it work?

Couldn't assess
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
Not assessable

We hold no graded evidence for this product's ingredients for its stated purpose.

Why this rating?
  • The label markets this product for: energy production and metabolism.
  • Our graded evidence for these ingredients doesn't cover that particular purpose.

The product facts we have don't include effectiveness ratings for riboflavin at this dose or for any specific health condition. If you're considering this supplement for a particular reason, ask us what the evidence shows for your situation.

The evidence, ingredient by ingredient Riboflavin

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.

Riboflavin is considered very safe — your body removes excess amounts through your urine. At this 400 mg dose, the most common side effects are dose-related nausea and bright yellow urine discoloration, which is harmless.

A small number of people have reported diarrhea or increased urination, but these are rare. Riboflavin is needed during pregnancy and breastfeeding and is generally safe at recommended amounts.

If you're pregnant or nursing and want to take a higher-dose supplement like this one, check with your provider first to make sure it's right for you.

Side effects, ingredient by ingredient Riboflavin

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?
  • 1 of the 1 matched ingredient can interact with medications — Riboflavin.
  • The most serious interaction on file is rated Moderate.
  • 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 tetracycline antibiotics (such as doxycycline, minocycline, or tetracycline), check with your pharmacist before starting this supplement — riboflavin may reduce their potency. Use the medication checker on this page to verify your other medications.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with no assessable stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

This B-2 supplement is generally well tolerated and safe for most people. If you take tetracycline antibiotics, let us know before you start it — we'll help you work around the potential interaction.

Bright yellow urine is normal and harmless at this dose. Ask your pharmacist if this supplement fits your health goals.

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 Jun 16, 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 Vitamin B-2 400 mg, straight from the product label.

Brand Best Naturals
Barcode (UPC) 817716014975
Net contents 120 Vegetarian Capsule(s)
Market status On market
Date entered into DSLD Jun 16, 2022
DSLD ID 270864
Product type Vitamin
Supplement form Capsule
Dietary claims / uses Nutrient, All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free, Dairy Free, Sugar 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 Vitamin B-2 400 mg by Best Naturals, 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 Vegetarian Capsule(s)
Maximum serving Sizes:
1 Vegetarian Capsule(s)
Servings per container
120
UPC/BARCODE
817716014975
IngredientAmount% DV
Riboflavin400 mg30769%

Other ingredients: Capsule, Magnesium Stearate, Silicon Dioxide

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

Vitamin B-2, also known as Riboflavin, is a member of the B-vitamin family. It occurs naturally in green vegetables, liver, kidneys, wheat germ, milk, eggs, cheese and fish. It is essential nutrient for energy production and the metabolism of carbohydrates, fats, and proteins. Certain research publications indicate that Vitamin B-2 may help support the following: Supports healthy nervous system. Supports healthy vision, skin and hair. Supports fat & energy metabolism.

(Riboflavin)

Precautions

Caution: For adults only, if you are pregnant, nursing, taking any medications or have any medical condition, consult your doctor before use.

Caution: For adults only, if you are pregnant, nursing, taking any medications or have any medical condition, consult your doctor before use. Discontinue use and consult your doctor if any adverse reactions occur.

Keep out of the reach of children.

Do not use if safety seal is broken or missing.

Storage

Keep in cool, dry place.

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.

Seals/Symbols

Made in USA

GMP Good Manufacturing Practice Product

Formulation

Premium formula

3rd party lab tested

No artificial color, flavor or sweetener, no preservatives, no sugar, no starch, no milk, no corn, no soy, no egg, no lactose, no gluten, no wheat, no yeast, no fish.

FDA Statement of Identity

Dietary Supplement

Suggested/Recommended/Usage/Directions

Suggested Use: As a dietary supplement, take 1 capsule daily with a meal or as directed by your qualified health care professional.

General Statements

For additional information call 1-877-659-6004

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

See for yourself

Vitamin B-2 400 mg by Best Naturals label

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

Vitamin B-2 400 mg 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 B-2 400 mg by Best Naturals

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

Serving size1 Vegetarian Capsule(s) Dosage formCapsule Servings per container120 Amounts shown are per serving.

Riboflavin

Interacts with
20 drugs
400 mg per serving Form: Vitamin B2

Riboflavin (vitamin B2) is an essential nutrient your body needs to turn food into energy and to keep skin, eyes, and nerves healthy. It is generally...

Riboflavin monograph & interactions

Other (inactive) ingredients: Capsule, Magnesium Stearate, Silicon Dioxide. These complete the product’s ingredient list but are not active constituents.

Interaction report

Vitamin B-2 400 mg by Best Naturals Drug Interactions

Want to check YOUR meds against Vitamin B-2 400 mg?

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 Moderate

Ingredients driving the most interactions

Riboflavin 20

Individual Drug Interactions

The ingredients in Vitamin B-2 400 mg interact with 20 drugs. Click any drug to see the details.

1 of the 1 ingredient in Vitamin B-2 400 mg interact with drugs. Each result below shows which ingredient is responsible. Riboflavin

Each ingredient & the kinds of drugs it affects

For each ingredient in Vitamin B-2 400 mg 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.

Riboflavin1 drug type · 20 drugs

Tetracycline Antibiotics

Theoretically, taking riboflavin with tetracycline antibiotics may decrease the potency of these antibiotics.
In vitro research suggests that riboflavin may inhibit the potency of tetracycline antibiotics. It is not clear if this effect is clinically significant, as this interaction has not been reported in humans.

Likelihood Possible Evidence D
Riboflavin full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Vitamin B-2 400 mg, from the product label.

Best Naturals

See all Best Naturals products
Name
Best Naturals
Street Address
PO Box 394
City
Kenilworth
State
NJ
ZipCode
07033
Phone Number
1-877-659-6004
Web Address
www.shopbestnaturals.com
Pharmacist Counseling Corner

Vitamin B-2 400 mg by Best Naturals: Common Questions

Does Vitamin B-2 400 mg by Best Naturals interact with any medications?
Yes. Based on its ingredients, Vitamin B-2 400 mg 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 B-2 400 mg 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 turn my urine yellow?
Yes, bright yellow urine is a known and harmless side effect of riboflavin at this dose. It's just your body excreting excess B-2. It should go back to normal once you stop taking it.
Can I take this if I'm pregnant or breastfeeding?
Riboflavin is needed during pregnancy and breastfeeding. This 400 mg dose is considered generally safe at recommended amounts, but since it's a higher-dose supplement, talk with your provider first to confirm it's appropriate for you.
What side effects should I watch for?
Most people tolerate it well. Dose-related nausea and urine discoloration are the most common. Diarrhea and increased urination are rare. Stop taking it and call us if you have any unusual symptoms.
Is there anything I should avoid taking with this?
If you're on tetracycline antibiotics, let your pharmacist know before starting this — we may need to time your doses differently. Use our interaction checker for your other medications.
What is riboflavin used for?
Riboflavin (vitamin B-2) is a nutrient your body uses to convert food into energy and support healthy cell growth. It's one of the B vitamins. Ask us what the research shows if you're taking it for a specific health reason.

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

Not sure if Vitamin B-2 400 mg is safe with your meds?

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Ask a pharmacist

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 B-2 400 mg label
Go deeper

The Full Monographs Behind Vitamin B-2 400 mg’s Ingredients

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

Herb & supplement monograph

Riboflavin

Interacts with 20 drugs

Riboflavin (vitamin B2) is an essential nutrient your body needs to turn food into energy and to keep skin, eyes, and nerves healthy. It is generally very safe at typical doses, and the stro...

Read the full Riboflavin monograph →
Sources

Sources & How We Checked

Vitamin B-2 400 mg'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 5 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.

Riboflavin 5 references
  1. Schoenen J, Jacquy J, Lenaerts M. Effectiveness of high-dose riboflavin in migraine prophylaxis. A randomized controlled trial. Neurology 1998;50:466-70. PubMed
  2. Yates AA, Schlicker SA, Suitor CW. Dietary reference intakes: The new basis for recommendations for calcium and related nutrients, B vitamins, and choline. J Am Diet Assoc 1998;98:699-706. PubMed
  3. Leeson LJ, Weidenheimer JF. Stability of tetracycline and riboflavin. J Pharm Sci. 1969;58(3):355-7. PubMed
  4. MacLennan, S. C., Wade, F. M., Forrest, K. M., Ratanayake, P. D., Fagan, E., and Antony, J. High-dose riboflavin for migraine prophylaxis in children: a double-blind, randomized, placebo-controlled trial. J Child Neurol. 2008;23(11):1300-1304.
  5. Dietary reference intakes (DRIs): estimated average requirements. Food and Nutrition Board, Institute of Medicine, National Academics. https://www.nal.usda.gov/sites/default/files/fnic_uploads//recommended_intakes_individuals.pdf Accessed July 24, 2017.

See these in context on the Riboflavin 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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