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Dietary supplement

Vitamin B2 400 mg Ingredients & Drug Interactions

by Nutricost

Vitamin B2 400 mg label
See full label image
Capsule Category: Vitamin
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 9, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Vitamin B2 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 B2 400 mg is a dietary supplement by Nutricost 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 B2 400 mg by Nutricost

Ask about any prescription or over-the-counter medication and we check it for interactions with Vitamin B2 400 mg by Nutricost — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Vitamin B2 400 mg by Nutricost

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 B2) at 400 mg per capsule. Riboflavin is a B vitamin that plays a role in energy production and cell function.

The capsule also contains inactive ingredients — rice flour, gelatin, magnesium stearate, silica, and stearic acid — which are fillers and binders that hold the supplement together.

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

This is a single-ingredient Riboflavin product and its label doesn't state a use — see Riboflavin's own graded uses on its monograph.

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.

The product facts don't include effectiveness ratings for riboflavin. We hold no data on how well this dose works for any specific purpose, so we can't tell you what the evidence shows.

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 clears excess through your urine. It's needed during both pregnancy and breastfeeding and is generally safe at recommended amounts; if you're pregnant, nursing, or considering higher-dose supplements, check with your provider first.

When taken by mouth, riboflavin is generally well tolerated. The most common side effects are dose-related nausea and bright yellow urine discoloration — harmless, but noticeable.

Diarrhea and increased urination have been reported rarely, including in one person out of a clinical trial of 28 participants taking 400 mg daily.

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.

Check your medications if you take tetracycline antibiotics such as doxycycline or minocycline — riboflavin may theoretically reduce their potency, though this hasn't been confirmed in patients. 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 glanceFully disclosed formula with no assessable stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

This product is well tolerated for most people and the dose is generally safe. If you take tetracycline antibiotics (like doxycycline), check with your pharmacist first — there's a theoretical concern they might be less effective, though it hasn't been proven in patients.

For pregnancy, breastfeeding, or any other medications, run this through your pharmacist to be sure.

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 Feb 22, 2024.

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 B2 400 mg, straight from the product label.

Brand Nutricost
Barcode (UPC) 702669933155
Net contents 120 Capsule(s)
Market status On market
Date entered into DSLD Feb 22, 2024
DSLD ID 306404
Product type Vitamin
Supplement form Capsule
Dietary claims / uses Nutrient, All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten 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 B2 400 mg by Nutricost, 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 Capsule(s)
Maximum serving Sizes:
1 Capsule(s)
Servings per container
120
UPC/BARCODE
702669933155
IngredientAmount% DV
Riboflavin400 mg30770%

Other ingredients: Rice Flour, Gelatin, Magnesium Stearate, Silica, Stearic Acid

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 use: as a dietary supplement, take 1 capsule daily with 8-12oz of water or as directed by your healthcare professional.

Formulation

Third party tested

Non-GMO Gluten-free

Made and quality tested in the USA with globally sourced ingredients.

Non-GMO product

Precautions

Warning: for healthy individuals 18 years and older. Keep out of reach of children.

Consult a healthcare professional prior to use if you are pregnant or nursing, taking medication, or have a medical condition.

Do not use if safety seal is broken or missing.

Storage

Notice: store in a cool, dry place.

Formula

Riboflavin Vitamin B2 400mg per serving

FDA Statement of Identity

Dietary Supplement

Seals/Symbols

Quality Nutricost Guaranteed GMP Compliant Facility Third Party Tested

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.

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

See for yourself

Vitamin B2 400 mg by Nutricost label

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

Vitamin B2 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 B2 400 mg by Nutricost

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

Serving size1 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: Rice Flour, Gelatin, Magnesium Stearate, Silica, Stearic Acid. These complete the product’s ingredient list but are not active constituents.

Interaction report

Vitamin B2 400 mg by Nutricost Drug Interactions

Want to check YOUR meds against Vitamin B2 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 B2 400 mg interact with 20 drugs. Click any drug to see the details.

1 of the 1 ingredient in Vitamin B2 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 B2 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 B2 400 mg, from the product label.

Nutricost

See all Nutricost products
Name
Nutricost
Street Address
351 E 1750 N
City
Vineyard
State
UT
ZipCode
84059
Phone Number
(866) 438-3694
Web Address
www.nutricost.com
Pharmacist Counseling Corner

Vitamin B2 400 mg by Nutricost: Common Questions

Does Vitamin B2 400 mg by Nutricost interact with any medications?
Yes. Based on its ingredients, Vitamin B2 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 B2 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 make my urine yellow?
Yes, it can — bright yellow urine is a known side effect of riboflavin, especially at higher doses like 400 mg. It's harmless and just means your body is clearing excess vitamin. The color should go away once you stop taking it.
Is this safe to take while pregnant or breastfeeding?
Riboflavin is actually needed during pregnancy and breastfeeding and is generally safe at recommended amounts. That said, this is a high-dose supplement, so check with your doctor or midwife before you start it.
Can I take this with my antibiotics?
Most antibiotics are fine, but if you're on a tetracycline antibiotic like doxycycline, talk to your pharmacist first. There's a theoretical concern that riboflavin might make these antibiotics less effective, though it hasn't been proven in real patients.
What side effects should I expect?
Most people tolerate it well. Nausea and yellow urine are the most common, especially at this 400 mg dose. Diarrhea and increased urination are rare — they happened in only one person in a clinical trial of 28 participants.
Is riboflavin the same as vitamin B2?
Yes — riboflavin is the scientific name for vitamin B2. This product gives you 400 mg of it per capsule.

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

Not sure if Vitamin B2 400 mg is safe with your meds?

Our pharmacists answer your medication & supplement questions — free.

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 B2 400 mg label
Go deeper

The Full Monographs Behind Vitamin B2 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 B2 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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