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Dietary supplement

Riboflavin Vitamin B2 400 mg Ingredients & Drug Interactions

by Nature's Way

Riboflavin Vitamin B2 400 mg label
See full label image
Tablet Or Pill 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 Riboflavin 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

Riboflavin Vitamin B2 400 mg is a dietary supplement by Nature's Way 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 Riboflavin Vitamin B2 400 mg by Nature's Way

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

Pharmacist-reviewed data Checks every ingredient Answer in seconds
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HelloPharmacist Scorecard of Riboflavin Vitamin B2 400 mg by Nature's Way

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, a B vitamin, at 400 mg per dose. The rest is inactive ingredients — cellulose, croscarmellose sodium, magnesium stearate, hypromellose, stearic acid, silica, glycerin, and carnauba wax — which are fillers and capsule materials.

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 metabolism support.
  • Our graded evidence for these ingredients doesn't cover that particular purpose.

We don't have effectiveness ratings for riboflavin in our data, so we can't speak to what research shows this dose might do for any particular health goal. If you're taking it for a specific reason, that's worth discussing with your pharmacist.

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 very well tolerated and generally safe; your body gets rid of the excess in urine. The most common side effect is dose-related nausea.

Some people also report bright yellow urine (which is harmless) and, rarely, diarrhea — in one small trial, one person out of 28 experienced diarrhea and one experienced increased urination after starting 400 mg daily. Riboflavin is needed during pregnancy and breastfeeding and is generally safe at standard doses, but check with your provider before taking a high-dose supplement like this one.

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.

Tetracycline antibiotics (like doxycycline) are the main ones to double-check. Riboflavin may theoretically reduce their effectiveness, though this hasn't been confirmed in humans.

Run your antibiotic through the search tool to be sure.

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 is a straightforward B-vitamin supplement that's well tolerated by most people. If you're on a tetracycline antibiotic, talk to your pharmacist before you start.

Pregnant or breastfeeding? Ask your provider about whether this high dose is right for you.

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 25, 2025.

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 Riboflavin Vitamin B2 400 mg, straight from the product label.

Brand Nature's Way
Barcode (UPC) 763948168439
Net contents 30 Tablet(s)
Market status On market
Date entered into DSLD Jun 25, 2025
DSLD ID 328041
Product type Vitamin
Supplement form Tablet Or Pill
Dietary claims / uses Nutrient, All Other, Structure/Function
Intended target group(s) Vegan, Vegetarian, Adult (18 - 50 Years), Gluten Free, Dairy Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Riboflavin Vitamin B2 400 mg by Nature's Way, 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 Tablet(s)
Maximum serving Sizes:
1 Tablet(s)
Servings per container
30
UPC/BARCODE
763948168439
IngredientAmount% DV
Riboflavin400 mg30769%

Other ingredients: Cellulose, Croscarmellose Sodium, Magnesium Stearate, Hypromellose, Stearic Acid, Silica, Glycerin, Carnauba Wax

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.
Formulation

Energy metabolism support Helps convert food to fuel

Gluten free. No wheat, soy, dairy, gelatin, or artificial colors. Vegan Gelatin free

Vegan Gelatin free

Bottled and tested in the USA

Formula

Also known as vitamin B2, an essential nutrient for general health

Riboflavin Vitamin B2 400 mg per serving

General Statements

Explore more products at naturesway.com

Questions? 1-800-962-8873/naturesway.com 50% Bottle made from 50% post consumer recycled plastic

Seals/Symbols

Vegan Gelatin free

Brand IP Statement(s)

Copyright 2023 Nature's Way Brands, LLC

FDA Disclaimer Statement

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

FDA Statement of Identity

Dietary Supplement

Suggested/Recommended/Usage/Directions

Recommendation: Adult take 1 tablet daily or as recommended by a healthcare professional.

Precautions

Warning: Do not use if you are taking any prescription drugs without seeking advice from your healthcare professional. If you are pregnant or nursing, consult a healthcare professional prior to use.

Avoid excessive exposure to UV radiation (e.g., sunlight, tanning) while using this product.

Keep out of reach of children.

Safety sealed with inner seal. Do not use if seal is broken or missing.

Storage

Keep tightly closed. Store at room temperature. Avoid excessive heat and direct sunlight.

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

See for yourself

Riboflavin Vitamin B2 400 mg by Nature's Way label

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

Riboflavin 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 Riboflavin Vitamin B2 400 mg by Nature's Way

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

Serving size1 Tablet(s) Dosage formTablet Or Pill Servings per container30 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: Cellulose, Croscarmellose Sodium, Magnesium Stearate, Hypromellose, Stearic Acid, Silica, Glycerin, Carnauba Wax. These complete the product’s ingredient list but are not active constituents.

Interaction report

Riboflavin Vitamin B2 400 mg by Nature's Way Drug Interactions

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

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

Nature's Way

See all Nature's Way products
Name
Nature's Way Brands, LLC
City
Green Bay
State
WI
ZipCode
54311
Phone Number
1-800-962-8873
Web Address
www.naturesway.com
Pharmacist Counseling Corner

Riboflavin Vitamin B2 400 mg by Nature's Way: Common Questions

Does Riboflavin Vitamin B2 400 mg by Nature's Way interact with any medications?
Yes. Based on its ingredients, Riboflavin 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?
Riboflavin 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 turn my urine yellow?
Yes, it can — bright yellow urine is a common effect of high-dose riboflavin and is completely harmless. It's just your body getting rid of extra B2.
Can I take this while pregnant or breastfeeding?
Riboflavin is actually needed during pregnancy and breastfeeding and is generally safe at standard doses. But since this is a 400 mg supplement (a high dose), talk with your doctor or midwife first to make sure it's right for you.
What's the most common side effect?
Nausea is the most common, and it's dose-related — meaning higher doses are more likely to cause it. It's usually mild.
Is this safe to take every day?
Riboflavin is very safe; excess amounts just leave your body through urine. Take it as directed on the label, and you should be fine.
What is riboflavin used for in the body?
Riboflavin is a B vitamin (also called B2) that your body needs for energy production and cell health. This product provides the vitamin in supplement form.

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

Not sure if Riboflavin Vitamin B2 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.

Riboflavin Vitamin B2 400 mg label
Go deeper

The Full Monographs Behind Riboflavin 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

Riboflavin 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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