Drug & supplement interaction

Riboflavin + Amoxicillin

Amoxicillin brand names: Amoxil Capsules, Trimox, Wymox, Amix, Amoram, and others.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 13, 2026
The bottom line No known interaction

We found no known interaction between Riboflavin and Amoxicillin in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first.

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Interaction report

Riboflavin and Amoxicillin

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Amoxicillin and Riboflavin in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

Riboflavin safety at a glance

Riboflavin overall Generally safe Riboflavin is considered very safe; excess is removed in the urine.
Pregnancy Likely Safe When used orally and appropriately in dietary amounts. A tolerable upper intake level (UL) has not been established. Read the full pregnancy detail
Breastfeeding Likely Safe When used orally and appropriately in dietary amounts. A tolerable upper intake level (UL) has not been established. Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center) — the full detail is in the Special populations card below. Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Amoxicillin and Riboflavin? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Amoxicillin

Interactions in our licensed database are recorded against drug classes, not just single drug names. Amoxicillin is filed under 7 classifications — including penicillin, antibiotic drugs, nephrotoxic drugs. Riboflavin has documented interactions with 1 drug class — the most serious being tetracycline antibiotics (moderate) — and none of Amoxicillin’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

Riboflavin Does Interact With Other Medications

Riboflavin has 20 moderate known drug interactions in our database — Amoxicillin isn’t one of them. If you take anything else, check it against the full list below.

Moderate 20 No known interaction 2,810 (incl. Amoxicillin)
Taking anything else?

Check Another of Your Medications Against Riboflavin

Covers the 2,830 medications we’ve checked against Riboflavin. Pick one to open its full report.

What to actually watch for

What Riboflavin Itself Has Been Linked To

This is not an interaction — nothing below involves Amoxicillin. It is the side-effect record for Riboflavin on its own, from the licensed Natural Medicines monograph. If something new turns up after you add Riboflavin, this list is the first place to look.

  • Passing urine more often Additional detail

    “Orally, high doses of riboflavin can cause bright yellow urine. Furthermore, in one clinical study, one subject out of 28 reported polyuria two weeks after starting riboflavin 400 mg daily.”

    Riboflavin · Natural Medicines adverse-effect record, reported in myasthenia gravis.

    2 sources cited
    1. 1398. 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. 3094. 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
  • Diarrhea Additional detail

    “Orally, riboflavin has been associated with rare diarrhea and dose-related nausea. In one clinical study, one subject out of 28 reported having diarrhea two weeks after starting riboflavin 400 mg daily.”

    Riboflavin · Natural Medicines adverse-effect record, reported in diarrhea.

    2 sources cited
    1. 1398. 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. 71483. 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.
  • Nausea Additional detail

    “Orally, riboflavin is generally well tolerated.

    Most Common Adverse Effects:

    Orally: Dose-related nausea and urine discoloration.”

    Riboflavin · Natural Medicines adverse-effect record, reported in nausea and vomiting.

Everything above comes from the Natural Medicines adverse-effect record for Riboflavin — expand a row for the licensed statement it rests on. We haven’t matched Amoxicillin to its FDA label in our system yet, so we can’t compare its own side-effect list here — the leaflet that comes with your prescription is the authoritative list for Amoxicillin.

Special populations

Riboflavin in Pregnancy & Breastfeeding

Pregnancy And Lactation Likely Safe

When used orally and appropriately in dietary amounts. A tolerable upper intake level (UL) has not been established.

DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.© 2026 Therapeutic Research Center

Worth knowing

No Interaction — But Amoxicillin May Lower Your Riboflavin Levels

These two do not interact. The relationship runs the other way: the licensed record lists Amoxicillin as associated with lower Riboflavin levels — rated “Insignificant Depletion”.

Antibiotic drugs might reduce riboflavin levels; however, this is not likely to be clinically significant. Interference with the normal gastrointestinal flora by antibiotics may reduce bacterial synthesis of riboflavin. However, this synthesis doesn't seem to significantly contribute to the body's supply of riboflavin, which is primarily obtained from dietary sources. Riboflavin supplements aren't necessary during antibiotic therapy.

RIBOFLAVIN — Insignificant Depletion

See every medication linked to lower Riboflavin levels · See the full Amoxicillin nutrient report

Disclaimer: This checker finds which nutrients might be depleted by prescription or over-the-counter medications. Each nutrient depletion issue is rated based on clinical significance. Use your own professional judgment prior to making clinical decisions.© 2026 Therapeutic Research Center

From our Q&A

Questions About Riboflavin or Amoxicillin

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Riboflavin or Amoxicillin, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Amoxicillin

This page covers Riboflavin only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Amoxicillin page lists 96 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Asarabacca (major), Beer (major), Khat (major) and Siberian Cocklebur (major).

By severity: 6 major · 76 moderate · 14 minor.

From our pharmacist’s overview on the Amoxicillin page

“Amoxicillin, one of the most commonly prescribed antibiotics, has 96 supplement and herbal ingredients flagged against it, and six carry a major rating, which puts this list in the read-carefully category. The serious entries mostly add strain to organs the drug already touches.”

Reviewed by 2 · Jul 18, 2026

Open the Amoxicillin interaction page

One more smart check

Taking Riboflavin as Part of a Dietary Supplement Product? Check It for Interactions

We hold 18,014 real supplement products containing Riboflavin, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Riboflavin. Even though Riboflavin itself has no known interaction with Amoxicillin, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Riboflavin and Amoxicillin Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Riboflavin
Top 1%

#12 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Amoxicillin
Top 5%

#36 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every Riboflavin reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 13, 2026. The Riboflavin and Amoxicillin records this page draws on were last updated July 10, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About Riboflavin

What is Riboflavin?

  • Riboflavin deficiency
  • Migraine prevention
  • General energy and metabolism support
  • Healthy skin and eyes

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 strongest evidence supports its use for treating deficiency, with some supportive (but not definitive) evidence for preventing migraines.

Vitamin (water-soluble B vitamin) · Tablets, capsules, softgels, multivitamins, B-complex products, fortified foods

An interaction check asks whether these two react with each other — it does not ask whether Riboflavin is a good idea for someone in your situation. Here is what our Riboflavin record says about it on its own.

Riboflavin: dosing

There is a recommended daily intake for riboflavin as a nutrient, and most people meet it through a normal diet. Do not assume that more is better.

From our Riboflavin monograph — the full record covers uses, side effects and every documented interaction.

Read the full Riboflavin monograph & all interactions
Medication

About Amoxicillin

What Is Amoxicillin Used For?

Brand names: Amoxil Capsules, Trimox, Wymox, Amix, Amoram, Amoxident, Galenamox, Rimoxallin, Amoxil Injection

Amoxicillin treats bacterial infections in both adults and children, including ear, nose, and throat infections; lower respiratory tract infections; skin and skin structure infections; and genitourinary tract infections.

In adults only, amoxicillin is also used — always combined with other medications — to eradicate Helicobacter pylori (H. pylori), the bacteria behind duodenal ulcers. Getting rid of H. pylori has been shown to reduce the chance of those ulcers coming back. It is only effective against bacteria that are susceptible to it and will not work against viral infections like the common cold or flu.

Most-Reported Side Effects for Amoxicillin

From FAERS, the FDA’s public side-effect reporting system (0 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Diarrhea 6,010 reports
Drug hypersensitivity 5,482 reports
Nausea 5,158 reports
Dyspnea 5,001 reports
Acute kidney injury 4,989 reports
See full Amoxicillin drug information
Keep checking

Other Drugs & Riboflavin

Browse every other medication we’ve checked against Riboflavin — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
20Moderate
0Minor
2,809No known interaction
20 Moderate 2,809 No interaction
Moderate

20 interactions

No interaction 2,809 drugs checked — show the list

We also checked Riboflavin against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,809 medications checked with no known interaction — see the full Riboflavin list.

See the full Riboflavin interactions page
See every supplement checked against Amoxicillin, ranked by severity
Evidence & sources

Riboflavin References

The 5 references that drive our Riboflavin monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  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.

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking Riboflavin and Amoxicillin Together: Common Questions

Is it safe to take Riboflavin with Amoxicillin?
We do not list a known interaction between Riboflavin and Amoxicillin. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Can Amoxicillin lower my Riboflavin levels?
Natural Medicines records Amoxicillin as a medicine that can deplete Riboflavin. That is the opposite direction to an interaction — it is a reason some people are told to take a supplement, not a reason to avoid one. Do not start one on the strength of this page; ask your pharmacist or doctor whether it applies to you.
How was the Riboflavin and Amoxicillin combination checked?
Interactions in our licensed database are recorded against drug classes. Amoxicillin is filed under 7 classifications, and Riboflavin has documented interactions with 1 drug class — none of Amoxicillin's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does Riboflavin interact with any other medications?
Yes. Riboflavin has 20 documented drug interactions in our database — Amoxicillin is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Amoxicillin interact with any supplements?
Yes. Amoxicillin has documented interactions with 96 supplements in our database — Riboflavin is not one of them. The Amoxicillin interaction page linked on this page lists every one, ranked by severity.

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

Where next

Keep Exploring

Riboflavin monograph Uses, safety profile, and every drug interaction in one place Amoxicillin drug information The full plain-English guide to this medication Amoxicillin supplement interactions Every supplement checked against Amoxicillin, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 5 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Amoxicillin and Riboflavin?

Our pharmacists answer your medication & supplement questions — free.

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.