Interactions on record — worth a quick check against your medications. Check your meds →
Dietary supplement

Riboflavin 5'-Phosphate Ingredients & Drug Interactions

by Thorne

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 Thorne 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.

Jump to a section

Check Your Meds Against Riboflavin 5'-Phosphate by Thorne

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

Pharmacist-reviewed data Checks every ingredient Answer in seconds
Prefer a human? Send your question to our licensed pharmacists — free, answered by email within 24 hours.

HelloPharmacist Scorecard of Riboflavin 5'-Phosphate by Thorne

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 contains one active ingredient: riboflavin (also called vitamin B2), in the form of riboflavin 5'-phosphate. Riboflavin is a B vitamin your body needs to convert food into energy and support cellular function.

The inactive ingredients—hypromellose, microcrystalline cellulose, silicon dioxide, and calcium laurate—are capsule and tablet binders with no active role.

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 ratings for this product in our data, so we can't comment on how well it works for any particular purpose. If you're considering it for a specific health goal, talk with your doctor or pharmacist about whether the evidence supports it 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 considered very safe; your body removes excess amounts through urine. The most common side effects are dose-related nausea and bright yellow urine discoloration—both harmless.

A small number of people have reported diarrhea or increased urination at high doses, but these are rare. During pregnancy and breastfeeding, riboflavin is needed and generally safe at recommended doses.

If you're pregnant or nursing and considering a higher-dose supplement, check with your provider first.

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.

If you take tetracycline antibiotics (such as doxycycline), check with your doctor or pharmacist before starting this product. Riboflavin may theoretically reduce how well these antibiotics work, though this hasn't been confirmed in patients.

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 single-ingredient riboflavin supplement is well tolerated by most people and generally safe at standard doses. The main thing to watch is if you take a tetracycline antibiotic—check with your doctor or pharmacist before adding this in.

If you're pregnant, nursing, or on any regular medications, a quick conversation with your own healthcare provider will help you decide if it's 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 Aug 23, 2023.

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 Thorne
Barcode (UPC) 693749115021
Net contents 60 Capsule(s)
Market status On market
Date entered into DSLD Aug 23, 2023
DSLD ID 288632
Product type Vitamin
Supplement form Capsule
Dietary claims / uses All Other
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 Thorne, 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
60
UPC/BARCODE
693749115021
IngredientAmount% DV
Riboflavin36.5 mg2808%

Other ingredients: Hypromellose, Microcrystalline Cellulose, Silicon Dioxide, Calcium Laurate

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.
General Statements

Foundational

Suggested/Recommended/Usage/Directions

Suggested use: Take 1 capsule one to three times daily or as recommended by your health-care practitioner.

Precautions

Tamper evident: Use only if bottle is sealed.

If pregnant, consult your health-care practitioner before using this product.

Storage

Store tightly sealed in a cool, dry place.

Seals/Symbols

Manufactured in the USA using US & imported ingredients

Formulation

Gluten free

FDA Statement of Identity

Dietary Supplement

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

See for yourself

Riboflavin 5'-Phosphate by Thorne 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 Thorne

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 container60 Amounts shown are per serving.

Riboflavin

Interacts with
20 drugs
36.5 mg per serving Form: Riboflavin 5'-Phosphate Sodium

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: Hypromellose, Microcrystalline Cellulose, Silicon Dioxide, Calcium Laurate. These complete the product’s ingredient list but are not active constituents.

Interaction report

Riboflavin 5'-Phosphate by Thorne 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 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

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.

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 5'-Phosphate, from the product label.

Thorne

See all Thorne products
Name
Thorne Research, Inc.
Phone Number
1-800-228-1966
Pharmacist Counseling Corner

Riboflavin 5'-Phosphate by Thorne: Common Questions

Does Riboflavin 5'-Phosphate by Thorne 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.
Will this turn my urine bright yellow?
Possibly. High doses of riboflavin can cause bright yellow urine, which is harmless—it's just excess riboflavin your body is eliminating. This is dose-related, so lower doses are less likely to cause it.
Can I take this if I'm pregnant or breastfeeding?
Riboflavin is needed during pregnancy and breastfeeding and is generally safe at recommended amounts. If you're considering a higher-dose supplement, check with your doctor or pharmacist first for personalized advice.
What are the most common side effects?
Riboflavin is generally well tolerated. The most common side effects are dose-related nausea and bright yellow urine. Diarrhea and increased urination have been reported rarely at high doses.
What exactly is riboflavin 5'-phosphate?
It's riboflavin (vitamin B2) in a specific chemical form called the 5'-phosphate. It's the active form your body can use right away. It works the same way as regular riboflavin for supporting energy and cell function.

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

Not sure if Riboflavin 5'-Phosphate 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.

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

Keep exploring
Supplement interaction checker › Check any supplement or product against your medications Drug–drug interactions › Check two or more of your medications against each other Browse medications A–Z › Every drug we've checked against herbs & supplements NDC & pricing lookup › Find a drug’s NDCs, packaging and costs Ask a pharmacist › Free, personal answer from our licensed team