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Dietary supplement

Riboflavin-5-Phosphate Ingredients & Drug Interactions

by Douglas Laboratories

Riboflavin-5-Phosphate 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 Riboflavin-5-Phosphate 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 is a dietary supplement by Douglas Laboratories 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 5-Phosphate. 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 by Douglas Laboratories

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

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HelloPharmacist Scorecard of Riboflavin-5-Phosphate by Douglas Laboratories

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 supplement contains one active ingredient: riboflavin 5-phosphate, a highly absorbable form of riboflavin (vitamin B2). Your body uses riboflavin to convert food into energy and to support your nervous system and skin health.

The capsule also contains microcrystalline cellulose, gelatin, and vegetable stearate — the inactive ingredients that hold it 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 effectiveness data we hold doesn't include ratings for riboflavin 5-phosphate, so we can't tell you from our information what condition or outcome it's been studied for. If you're considering this supplement for a specific health goal, your doctor or pharmacist can help you weigh the evidence.

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 — your body simply removes excess through your urine. The most common side effects are dose-related nausea and bright yellow urine; in trials, a small number of people reported diarrhea or increased urination at high doses.

Riboflavin is considered likely safe in pregnancy and while breastfeeding at recommended amounts, since your body needs it during these times. If you're pregnant, nursing, or considering a high-dose supplement, check with your doctor or pharmacist about what'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.

Tetracycline antibiotics are the main ones to flag. Lab work suggests riboflavin may reduce their potency, though this hasn't been confirmed in people yet.

Check with your doctor or pharmacist if you're on doxycycline, minocycline, or other tetracyclines before you take this supplement.

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.

If you're on a tetracycline antibiotic, talk to your doctor or pharmacist before taking this supplement — they may suggest spacing doses or a different approach. For anyone else, riboflavin is generally very well tolerated, though you might notice yellow urine or mild nausea at higher doses.

Run your medications through the checker on this page, and confirm with your own healthcare provider before starting.

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 Aug 23, 2020.

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, straight from the product label.

Brand Douglas Laboratories
Barcode (UPC) 310539005156
Net contents 100 Capsule(s)
Market status On market
Date entered into DSLD Aug 23, 2020
DSLD ID 232533
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 Riboflavin-5-Phosphate by Douglas Laboratories, 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
100
UPC/BARCODE
310539005156
IngredientAmount% DV
Riboflavin 5-Phosphate10 mg--

Other ingredients: Microcrystalline Cellulose, Gelatin, Vegetable Stearate

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 Usage: As a dietary supplement, adults take 1 capsule daily or as directed by your health professional.

Precautions

Warning: If you are pregnant, nursing, have any health condition or taking any medication, consult your health professional before using this product.

Keep out of the reach of children.

Use only if safety seal is intact.

Storage

Store in a cool, dry place.

Formulation

Gluten-free, Non-GMO

FDA Disclaimer Statement

This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

General Statements

Scan to learn about our manufacturing excellence Contents may not fill package in order to accommodate required labeling. Please rely on stated quantity.

FDA Statement of Identity

Dietary Supplement

Formula

Vitamin B2

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

See for yourself

Riboflavin-5-Phosphate by Douglas Laboratories label

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

Riboflavin-5-Phosphate 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 by Douglas Laboratories

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 container100 Amounts shown are per serving.

Riboflavin 5-Phosphate

Interacts with
20 drugs
10 mg per serving

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 5-Phosphate monograph & interactions

Other (inactive) ingredients: Microcrystalline Cellulose, Gelatin, Vegetable Stearate. These complete the product’s ingredient list but are not active constituents.

Interaction report

Riboflavin-5-Phosphate by Douglas Laboratories Drug Interactions

Want to check YOUR meds against Riboflavin-5-Phosphate?

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 5-Phosphate 20

Individual Drug Interactions

The ingredients in Riboflavin-5-Phosphate interact with 20 drugs. Click any drug to see the details.

1 of the 1 ingredient in Riboflavin-5-Phosphate interact with drugs. Each result below shows which ingredient is responsible. Riboflavin 5-Phosphate

Each ingredient & the kinds of drugs it affects

For each ingredient in Riboflavin-5-Phosphate 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.

Riboflavin 5-Phosphate1 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 5-Phosphate full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Riboflavin-5-Phosphate, from the product label.

Douglas Laboratories

See all Douglas Laboratories products
Name
Douglas Laboratories
Street Address
600 Boyce Road
City
Pittsburgh
State
PA
ZipCode
15205
Phone Number
1.800.245.4440
Web Address
www.douglaslabs.com
Pharmacist Counseling Corner

Riboflavin-5-Phosphate by Douglas Laboratories: Common Questions

Does Riboflavin-5-Phosphate by Douglas Laboratories interact with any medications?
Yes. Based on its ingredients, Riboflavin-5-Phosphate 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 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 this safe if I'm pregnant or breastfeeding?
Yes — riboflavin is actually needed during pregnancy and breastfeeding, and it's considered likely safe at normal doses. If you're considering a high-dose supplement, though, check with your doctor or pharmacist first to make sure it's right for you.
Why does my urine turn bright yellow?
That's riboflavin — it's normal and harmless. Your body uses what it needs and gets rid of the rest through urine. The brighter the urine, the more you're excreting.
Are there any common side effects I should know about?
Most people tolerate it very well. At higher doses, some folks report mild nausea or see brighter-than-usual urine. Diarrhea and increased urination have been reported rarely in clinical studies.
What's the difference between riboflavin and riboflavin 5-phosphate?
Riboflavin 5-phosphate is a form of riboflavin (vitamin B2) that your body can absorb more readily. Both are the same essential B vitamin, just in different forms.
Can I take this with antibiotics?
It depends on which antibiotic. Tetracycline antibiotics (like doxycycline) are a concern — lab studies suggest riboflavin may interfere with how they work. Check with your doctor or pharmacist before combining them.

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

Not sure if Riboflavin-5-Phosphate 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 label
Go deeper

The Full Monographs Behind Riboflavin-5-Phosphate’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'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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