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Dietary supplement

Riboflavin Vitamin B2 USP Ingredients & Drug Interactions

by PureBulk.com

Riboflavin Vitamin B2 USP label
See full label image
Powder 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 USP 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 USP is a dietary supplement by PureBulk.com 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 Vitamin B2. 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 USP by PureBulk.com

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

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HelloPharmacist Scorecard of Riboflavin Vitamin B2 USP by PureBulk.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 Sep 10, 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 is pure riboflavin — that's vitamin B2, also called riboflavin USP. It's a water-soluble vitamin that your body uses to turn food into energy and to maintain healthy skin, eyes, and nerves.

Because it's water-soluble, your body doesn't store excess amounts; what you don't use is cleared through your urine. The product contains no inactive ingredients or fillers.

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.

We don't hold effectiveness data for riboflavin in our records, so we can't speak to what this supplement is intended to help with based on the information available to us.

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 generally well tolerated when taken by mouth. The most common side effects are dose-related nausea and bright yellow urine discoloration at higher doses.

Rarely, some people may experience diarrhea. One clinical trial participant reported increased urination at higher doses.

Riboflavin is needed during pregnancy and breastfeeding and is considered likely safe at recommended amounts. If you're thinking about using a high-dose supplement while pregnant or breastfeeding, talk with your doctor or pharmacist first — excess amounts are cleared in your urine, so your body handles it well, but personalized advice matters here.

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.

Before you start, double-check if you're taking any tetracycline antibiotics (Moderate severity) — riboflavin may theoretically reduce their effectiveness, though this hasn't been confirmed in patients. Use the search tool on this page to look up your exact antibiotic and confirm with your doctor or pharmacist.

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.

Riboflavin is a straightforward B vitamin supplement that's generally well tolerated. If you take tetracycline antibiotics, check with your doctor or pharmacist before adding this to make sure it won't affect how well your antibiotic works.

Otherwise, it's a good option for anyone looking to supplement this essential vitamin.

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, 2013.

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 USP, straight from the product label.

Brand PureBulk.com
Net contents 50 Gram(s); 1.76 oz.
Market status On market
Date entered into DSLD Jun 25, 2013
DSLD ID 23252
Product type Vitamin
Supplement form Powder
Dietary claims / uses 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 Riboflavin Vitamin B2 USP by PureBulk.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:
50 mg
Maximum serving Sizes:
50 mg
Servings per container
1000
IngredientAmount% DV
Vitamin B250 mg2941%

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.
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.

Storage

Storage: Keep dry, cool & dark

Formulation

Free of: Sugar, soy, dairy, yeast, gluten, corn and additives.

Suggested/Recommended/Usage/Directions

Directions: As a dietary supplement take 50 mg (1/32 tsp) once or twice daily, or as directed by physician. Individual needs vary greatly.

General Statements

US Standard Measuring Spoons Spoon Size (level) milligrams 1/32 teaspoon 48 1/16 teaspoon 97 1/8 teaspoon 194

Precautions

Warning: This product is not intended for use by those with a serious medical condition or pregnant or lactating women.

Consult your physician before use.

Keep out of reach of children.

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

See for yourself

Riboflavin Vitamin B2 USP by PureBulk.com label

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

Riboflavin Vitamin B2 USP 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 USP by PureBulk.com

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

Serving size50 mg Dosage formPowder Servings per container1000 Amounts shown are per serving.

Vitamin B2

Interacts with
20 drugs
50 mg per serving Form: Riboflavin

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...

Vitamin B2 monograph & interactions

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

Interaction report

Riboflavin Vitamin B2 USP by PureBulk.com Drug Interactions

Want to check YOUR meds against Riboflavin Vitamin B2 USP?

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

Vitamin B2 20

Individual Drug Interactions

The ingredients in Riboflavin Vitamin B2 USP interact with 20 drugs. Click any drug to see the details.

1 of the 1 ingredient in Riboflavin Vitamin B2 USP interact with drugs. Each result below shows which ingredient is responsible. Vitamin B2

Each ingredient & the kinds of drugs it affects

For each ingredient in Riboflavin Vitamin B2 USP 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 B21 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
Vitamin B2 full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Riboflavin Vitamin B2 USP, from the product label.

PureBulk.com

See all PureBulk.com products
Name
PureBulk.com
City
Roseburg
State
OR
ZipCode
97471
Phone Number
(541) 679-1500
Web Address
PureBulk.com
Pharmacist Counseling Corner

Riboflavin Vitamin B2 USP by PureBulk.com: Common Questions

Does Riboflavin Vitamin B2 USP by PureBulk.com interact with any medications?
Yes. Based on its ingredients, Riboflavin Vitamin B2 USP 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 USP 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.
Is riboflavin safe during pregnancy?
Yes — riboflavin is needed during pregnancy and is considered likely safe at recommended doses. If you're considering a high-dose supplement, check with your doctor or pharmacist for personalized guidance.
Is riboflavin safe while breastfeeding?
Yes — riboflavin is needed while breastfeeding and is considered likely safe at recommended amounts. Talk with your provider if you're thinking about taking higher doses.
Why does riboflavin turn my urine bright yellow?
That's normal and harmless. Riboflavin is water-soluble, so excess amounts that your body doesn't use are cleared through your urine — and riboflavin has a naturally bright yellow color.
What are the side effects of riboflavin?
It's generally well tolerated. At higher doses, some people may notice dose-related nausea or bright yellow urine. Rarely, diarrhea or increased urination has been reported.
Does my body store riboflavin?
No — riboflavin is water-soluble, so your body doesn't store extra amounts. What you don't use is removed through your urine, which is why excess is cleared safely.

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

Not sure if Riboflavin Vitamin B2 USP 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 USP label
Go deeper

The Full Monographs Behind Riboflavin Vitamin B2 USP’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 USP'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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