Riboflavin + Tipiracil Hydrochloride, Trifluridine
Tipiracil Hydrochloride, Trifluridine brand name: Lonsurf.
We found no known interaction between Riboflavin and Tipiracil Hydrochloride, Trifluridine 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. Additionally, although there is no interaction, the label for Tipiracil Hydrochloride, Trifluridine states a food rule worth keeping to, and the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.
Riboflavin and Tipiracil Hydrochloride, Trifluridine
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 Tipiracil Hydrochloride, Trifluridine 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
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.
Why No Interaction Is Listed for Tipiracil Hydrochloride, Trifluridine
Interactions in our licensed database are recorded against drug classes, not just single drug names. Tipiracil Hydrochloride, Trifluridine is filed under a single classification — oral drugs. Riboflavin has documented interactions with 1 drug class — the most serious being tetracycline antibiotics (moderate) — and none of Tipiracil Hydrochloride, Trifluridine’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.
Riboflavin Does Interact With Other Medications
Riboflavin has 20 moderate known drug interactions in our database — Tipiracil Hydrochloride, Trifluridine isn’t one of them. If you take anything else, check it against the full list below.
Check Another of Your Medications Against Riboflavin
We haven’t checked that one against Riboflavin yet — ask our pharmacists directly.
Covers the 2,830 medications we’ve checked against Riboflavin. Pick one to open its full report.
Riboflavin in Pregnancy & Breastfeeding
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
Some Tipiracil Hydrochloride, Trifluridine Products Have a Food Rule — Riboflavin Should Not Break It
At least one FDA label for a product containing Tipiracil Hydrochloride, Trifluridine says to take it with food. If you take Riboflavin on an empty stomach out of habit, keep them separate — and take Tipiracil Hydrochloride, Trifluridine with a meal where the label says to.
This may not be true of your version. Food instructions belong to the product, not the ingredient: two Tipiracil Hydrochloride, Trifluridine products can carry different directions, and extended-release forms often differ from immediate-release ones. The label we read is quoted below — check the directions on your own box or bottle, or ask your pharmacist, for how to take the exact product you were given.
2 DOSAGE AND ADMINISTRATION Recommended Dosage : 35 mg/m 2 /dose orally twice daily with food on Days 1 through 5 and Days 8 through 12 of each 28-day cycle.
From the Dosage and Administration section of the FDA label we read for Tipiracil Hydrochloride, Trifluridine — where that label names a specific product, the instruction is that product's. Read the label on DailyMed ›
A food rule is not an interaction — it is about how much of the medicine you absorb. The directions that came with your own product, and your pharmacist, outrank anything on this page.
What Tipiracil Hydrochloride, Trifluridine Is Prescribed For, and What Riboflavin Has Been Studied For
These two come up together because they touch the same health topic — not because they do the same job. Tipiracil Hydrochloride, Trifluridine is a prescription medicine with approved uses on its FDA label. Riboflavin is a supplement: what follows is what researchers have looked at it for, and how strong that evidence is.
Tipiracil Hydrochloride, Trifluridine is prescribed for: Trifluridine and tipiracil (sold as Lonsurf) treats two types of advanced cancer in adults. Both are used after other treatments have already been tried. Lonsurf is used for metastatic colorectal cancer, either alone or together with bevacizumab. It is also used for metastatic gastric or gastroesophageal junction adenocarcinoma (cancer where the stomach meets the esophagus).
Riboflavin has been studied for:
-
Colorectal cancer studied, not established Riboflavin has been studied for this. Natural Medicines rates the evidence: Insufficient Reliable Evidence To Rate Read what the research shows
Riboflavin for colorectal cancer
It is unclear if oral riboflavin reduces colorectal cancer risk.
Effectiveness ratings and the research summaries above are the verbatim record from the Natural Medicines database, which grades evidence from “Effective” down to “Insufficient Reliable Evidence To Rate”. A rating below the top of that scale means researchers have looked at it — not that it works, and never that it can stand in for a prescribed medicine. Do not stop or replace Tipiracil Hydrochloride, Trifluridine on your own; if you are taking Riboflavin for the same health topic, tell your prescriber, especially if the medicine is being adjusted to a target.
See Every Supplement That Interacts With Tipiracil Hydrochloride, Trifluridine
This page covers Riboflavin only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Tipiracil Hydrochloride, Trifluridine page lists 17 supplements it has a documented interaction with, worst first, each one explained.
The most serious there right now: Activated Charcoal (major), Coffee Charcoal (moderate), European Mandrake (moderate), Glucomannan (moderate) and Guar Gum (moderate).
By severity: 1 major · 7 moderate · 9 minor.
Open the Tipiracil Hydrochloride, Trifluridine interaction page
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 Tipiracil Hydrochloride, Trifluridine, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:
Where Riboflavin and Tipiracil Hydrochloride, Trifluridine 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.
#12 of 1,452 supplements looked up here in the last 7 days
#537 of 2,830 medications looked up here in the last 7 days
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 October 4, 2026. The Riboflavin and Tipiracil Hydrochloride, Trifluridine 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.
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.
About Trifluridine and Tipiracil
What Is Trifluridine and Tipiracil Used For?
Brand name: Lonsurf
Trifluridine and tipiracil (sold as Lonsurf) treats two types of advanced cancer in adults. Both are used after other treatments have already been tried.
Lonsurf is used for metastatic colorectal cancer, either alone or together with bevacizumab. It is also used for metastatic gastric or gastroesophageal junction adenocarcinoma (cancer where the stomach meets the esophagus).
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.
No drugs match “”.
20 interactions
- Doxycycline ›
- Minocycline ›
- Tetracycline ›
- Doxycycline Hyclate ›
- Minocycline Hydrochloride ›
- Retapamulin ›
- Chlortetracycline ›
- Demeclocycline ›
- Doripenem ›
- Doxycycline Monohydrate ›
- Doxycyline ›
- Eravacycline ›
- Omadacycline (iv) ›
- Omadacycline (oral) ›
- Oxytetracycline ›
- Tigecycline ›
- Amphotericin, Tetracycline ›
- Bismuth Subsalicylate, Metronidazole, Tetracycline ›
- Metronidazole, Tetracyline, Bismuth Subcitrate Potassium ›
- Oxytetracycline, Phenazopyridine, Sulfamethizole ›
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.
- Apixaban ›
- Levothyroxine ›
- Amlodipine ›
- Methylphenidate ›
- Warfarin ›
- Ivermectin ›
- Abemaciclib ›
- Testosterone ›
- Losartan Potassium ›
- Sertraline ›
- Acetaminophen ›
- Rosuvastatin ›
- Aspirin ›
- Metoprolol ›
- Escitalopram ›
- Clopidogrel ›
- Atorvastatin ›
- Rivaroxaban ›
- Isotretinoin ›
- Tirzepatide ›
- Ibuprofen ›
- Warfarin Sodium ›
- Levothyroxine, Liothyronine ›
- Amlodipine Besylate ›
- Docusate ›
- Methamphetamine ›
- Amitriptyline ›
- Prednisone ›
- Metformin ›
- Tadalafil ›
- Lisdexamfetamine ›
- Semaglutide ›
- Hydroxyurea ›
- Valacyclovir ›
- Amphetamine ›
- Propranolol ›
- Sumatriptan ›
- Methotrexate ›
- Lisinopril ›
- Amoxicillin ›
- Bupropion ›
- Fluoxetine ›
- Azithromycin ›
- Pregabalin ›
- Gabapentin ›
- Acetaminophen, Aspirin, Caffeine ›
- Dextroamphetamine ›
- Naproxen ›
- Lamotrigine ›
- Bendamustine ›
- Quetiapine ›
- Clonazepam ›
- Acyclovir ›
- Buspirone ›
- Duloxetine ›
- Omeprazole ›
- Letrozole ›
- Citalopram ›
- Methylene Blue ›
- Ciprofloxacin ›
Showing the 60 most looked-up of 2,809 medications checked with no known interaction — see the full Riboflavin list.
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.
- Schoenen J, Jacquy J, Lenaerts M. Effectiveness of high-dose riboflavin in migraine prophylaxis. A randomized controlled trial. Neurology 1998;50:466-70. PubMed
- 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
- Leeson LJ, Weidenheimer JF. Stability of tetracycline and riboflavin. J Pharm Sci. 1969;58(3):355-7. PubMed
- 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.
- 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.
Taking Riboflavin and Tipiracil Hydrochloride, Trifluridine Together: Common Questions
Is it safe to take Riboflavin with Tipiracil Hydrochloride, Trifluridine?
Do Riboflavin and Tipiracil Hydrochloride, Trifluridine have any of the same side effects?
Should I take Riboflavin and Tipiracil Hydrochloride, Trifluridine at the same time of day?
Are Riboflavin and Tipiracil Hydrochloride, Trifluridine used for the same thing?
How was the Riboflavin and Tipiracil Hydrochloride, Trifluridine combination checked?
Does Riboflavin interact with any other medications?
Does Tipiracil Hydrochloride, Trifluridine interact with any supplements?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
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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.