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Dietary supplement

R-5-P 50 mg Ingredients & Drug Interactions

by Swanson

R-5-P 50 mg label
See full label image
Capsule Category: Vitamin
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 9, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking R-5-P 50 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

R-5-P 50 mg is a dietary supplement by Swanson 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 R-5-P 50 mg by Swanson

Ask about any prescription or over-the-counter medication and we check it for interactions with R-5-P 50 mg by Swanson — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
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HelloPharmacist Scorecard of R-5-P 50 mg by Swanson

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, a form of vitamin B2, at 50 mg per capsule. Riboflavin is a water-soluble vitamin that plays a role in energy production and other metabolic processes in your body.

The capsule also includes inactive ingredients — brown rice flour, hypromellose (a capsule binder), and L-leucine.

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

We don't hold effectiveness ratings for riboflavin in our data, so we can't tell you what clinical evidence shows about this dose for any particular use.

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 at recommended doses. The most common side effects are dose-related nausea and bright yellow urine discoloration — both harmless and temporary.

A small number of trial participants on much higher doses (400 mg daily) reported diarrhea or increased urination, but these are rare. Since riboflavin is water-soluble, excess amounts are removed through your urine.

Riboflavin is needed during pregnancy and breastfeeding and is considered likely safe at recommended amounts. If you're pregnant, nursing, or considering high-dose supplementation, check with your doctor or pharmacist for personalized guidance.

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 or tetracycline), confirm with your doctor or pharmacist before adding this supplement — riboflavin may theoretically reduce their effectiveness, though this hasn't been confirmed in humans.

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.

R-5-P is a straightforward riboflavin supplement that's very well tolerated at this dose. The main caution is if you take tetracycline antibiotics — check that combination with your doctor or pharmacist first.

Otherwise, it's a low-risk product for most people.

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 Apr 23, 2024.

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 R-5-P 50 mg, straight from the product label.

Brand Swanson
Barcode (UPC) 087614029009
Net contents 60 Veggie Cap(s)
Market status On market
Date entered into DSLD Apr 23, 2024
DSLD ID 308727
Product type Vitamin
Supplement form Capsule
Dietary claims / uses Nutrient, All Other, Structure/Function
Intended target group(s) Vegetarian, Adult (18 - 50 Years)
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 R-5-P 50 mg by Swanson, 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 Veggie Capsule(s)
Maximum serving Sizes:
1 Veggie Capsule(s)
Servings per container
60
UPC/BARCODE
087614029009
IngredientAmount% DV
Riboflavin50 mg3846%

Other ingredients: Brown Rice Flour, Hypromellose, L-Leucine

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.
Formula

Delivers B2 directly in its active form so its ready to perform

R-5-P 50mg per capsule Riboflavin-5-Phosphate Coenzymated vitamin B2

Formulation

Essential for cellular energy metabolism

Vegetarian

Energy and metabolism

Brand IP Statement(s)

Swanson Science-Backed Quality Since 1969

Suggested/Recommended/Usage/Directions

Suggested use: As a dietary supplement, take one veggie capsule one to two times per day with water.

Precautions

Warning: For adults only. Keep out of reach of children.

Consult your healthcare provider before using this or any product if you are pregnant or nursing, taking medication, or have a medical condition.

Do not use if seal is broken.

Storage

Store in a cool, dry place.

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.

FDA Statement of Identity

Vitamin Supplement

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

See for yourself

R-5-P 50 mg by Swanson label

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

R-5-P 50 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 R-5-P 50 mg by Swanson

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

Serving size1 Veggie Capsule(s) Dosage formCapsule Servings per container60 Amounts shown are per serving.

Riboflavin

Interacts with
20 drugs
50 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...

Riboflavin monograph & interactions

Other (inactive) ingredients: Brown Rice Flour, Hypromellose, L-Leucine. These complete the product’s ingredient list but are not active constituents.

Interaction report

R-5-P 50 mg by Swanson Drug Interactions

Want to check YOUR meds against R-5-P 50 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 R-5-P 50 mg interact with 20 drugs. Click any drug to see the details.

1 of the 1 ingredient in R-5-P 50 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 R-5-P 50 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 R-5-P 50 mg, from the product label.

Swanson

See all Swanson products
Name
Swanson Health Products
City
Fargo
State
ND
ZipCode
58104
Phone Number
1-800-437-4148
Web Address
swanson.com
Pharmacist Counseling Corner

R-5-P 50 mg by Swanson: Common Questions

Does R-5-P 50 mg by Swanson interact with any medications?
Yes. Based on its ingredients, R-5-P 50 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?
R-5-P 50 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 bright yellow?
Yes, you may notice bright yellow urine, especially at higher doses. That's normal and harmless — it's excess riboflavin being cleared through your kidneys. It will go back to normal once you stop taking it.
Is riboflavin safe during pregnancy or breastfeeding?
Riboflavin is needed during both pregnancy and breastfeeding and is considered likely safe at recommended amounts. If you're thinking about taking a high-dose supplement, talk with your doctor or pharmacist first to make sure it's right for you.
Can this cause nausea?
Dose-related nausea is the most common side effect, and it's more likely at higher doses. At 50 mg, the risk is low. If you do feel queasy, you can try taking it with food.
Is there anything else in this capsule besides riboflavin?
The capsule also contains brown rice flour, hypromellose (a binder), and L-leucine. These are all inactive ingredients and don't provide any therapeutic effect — they're just there to hold the capsule together.

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

Not sure if R-5-P 50 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.

R-5-P 50 mg label
Go deeper

The Full Monographs Behind R-5-P 50 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

R-5-P 50 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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