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Dietary supplement

Riboflavin 5 Phosphate Vitamin B2 Ingredients & Drug Interactions

by PureBulk.com

Riboflavin 5 Phosphate Vitamin B2 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 5 Phosphate Vitamin B2 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 5 Phosphate Vitamin B2 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 5 Phosphate Vitamin B2 by PureBulk.com

Ask about any prescription or over-the-counter medication and we check it for interactions with Riboflavin 5 Phosphate Vitamin B2 by PureBulk.com — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Riboflavin 5 Phosphate Vitamin B2 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 is a single-ingredient supplement: vitamin B2 (riboflavin), in the phosphate form. Riboflavin is a B vitamin your body uses for energy production, cell growth, and protecting cells from damage.

The product contains no inactive ingredients listed.

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 on this form of riboflavin for any specific health purpose in the facts provided. If you're considering it for a particular condition, talk it over with your doctor or pharmacist about 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 generally well tolerated. Your body flushes out what it doesn't need in the urine, which can turn bright yellow—that's harmless.

At higher doses, some people report nausea, and rarely, diarrhea or increased urination. Riboflavin is considered safe during pregnancy and breastfeeding at recommended amounts because your body needs it for both.

If you're thinking about taking a high-dose supplement while pregnant or nursing, check with your doctor or pharmacist first to make sure the dose is 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.

Tetracycline antibiotics (Moderate severity): riboflavin may reduce their effectiveness. Check with your doctor or pharmacist before combining this supplement with any tetracycline antibiotic.

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, single-ingredient B vitamin supplement that's generally well tolerated and safe at normal doses. The main concern is if you take tetracycline antibiotics—riboflavin may weaken them.

Before starting, check your medications with your own doctor or pharmacist, especially any antibiotics.

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 Oct 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 5 Phosphate Vitamin B2, straight from the product label.

Brand PureBulk.com
Net contents 10 Gram(s); 0.35 oz.
Market status On market
Date entered into DSLD Oct 25, 2013
DSLD ID 23255
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 5 Phosphate Vitamin B2 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:
75 mg
Maximum serving Sizes:
75 mg
Servings per container
133
IngredientAmount% DV
Vitamin B256 mg3294%

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.
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 75 mg (1/64 tsp) once or twice daily, or as directed by physician. Individual needs vary greatly.

General Statements

US Standard Measuring Spoons Spoon Size (level) milligrams 1/64 teaspoon 76 1/32 teaspoon 152 1/16 teaspoon 304

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.

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

Riboflavin 5 Phosphate Vitamin B2 by PureBulk.com label

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

Riboflavin 5 Phosphate Vitamin B2 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 5 Phosphate Vitamin B2 by PureBulk.com

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

Serving size75 mg Dosage formPowder Servings per container133 Amounts shown are per serving.

Vitamin B2

Interacts with
20 drugs
56 mg per serving Form: Riboflavin 5-Phosphate

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 5 Phosphate Vitamin B2 by PureBulk.com Drug Interactions

Want to check YOUR meds against Riboflavin 5 Phosphate Vitamin B2?

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 5 Phosphate Vitamin B2 interact with 20 drugs. Click any drug to see the details.

1 of the 1 ingredient in Riboflavin 5 Phosphate Vitamin B2 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 5 Phosphate Vitamin B2 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 5 Phosphate Vitamin B2, 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 5 Phosphate Vitamin B2 by PureBulk.com: Common Questions

Does Riboflavin 5 Phosphate Vitamin B2 by PureBulk.com interact with any medications?
Yes. Based on its ingredients, Riboflavin 5 Phosphate Vitamin B2 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 5 Phosphate Vitamin B2 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.
What is vitamin B2 (riboflavin) used for in the body?
Riboflavin helps your body produce energy, supports cell growth, and protects cells from damage. It's an essential nutrient you get from food or supplements.
Can I take this if I'm pregnant or breastfeeding?
Riboflavin is needed during pregnancy and breastfeeding and is considered safe at recommended amounts. If you're thinking about a high-dose supplement, talk with your doctor or pharmacist first to confirm the dose is right for you.
What are the most common side effects?
Riboflavin is generally well tolerated. At higher doses, some people experience nausea or bright yellow urine (harmless). Rarely, diarrhea or increased urination occurs.
Does excess riboflavin stay in my body?
No. Your body removes what it doesn't use through the urine, which is why high doses can turn your urine bright yellow.

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

Not sure if Riboflavin 5 Phosphate Vitamin B2 is safe with your meds?

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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.

Riboflavin 5 Phosphate Vitamin B2 label
Go deeper

The Full Monographs Behind Riboflavin 5 Phosphate Vitamin B2’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 5 Phosphate Vitamin B2'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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