Vitamin B2 (Riboflavin)

Pronunciation: rye-BOE-flay-vin.

Generic name
riboflavin
Drug class
Water-soluble B vitamin
Form
Dietary supplement; also naturally occurring in food
Route
Oral
Legal status
Available without a prescription

Availability and supply rules vary by country

Trade names by country: United States

Australia: · Full directory

What riboflavin is and how it works

Riboflavin, also called vitamin B2, is a water-soluble essential B vitamin. It is a component of the coenzymes flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), which have roles in energy production, cellular function, growth and development, and metabolism of fats, drugs, and steroids. (1) (2)

The body does not store riboflavin and continuously excretes it, so regular intake is needed. Riboflavin deficiency is uncommon but can cause symptoms including cracked lips and inflammation of the mouth.

Mechanism of action: how riboflavin works

Riboflavin is an essential water-soluble B vitamin and a component of FMN and FAD. These coenzymes have major roles in energy production, cellular function, growth and development, and metabolism of fats, drugs, and steroids. Riboflavin is needed to break down carbohydrates, proteins, and fats and to enable the body's use of oxygen. (1) (2) (3)

What riboflavin is used for

Riboflavin deficiency

Riboflavin is used to treat riboflavin-deficiency conditions. Deficiency can cause symptoms including cracked lips, mouth inflammation, itching or burning eyes, sensitivity of the eyes to light, and a sore tongue. (1) (2)

Migraine prevention

Source characterizations differ. A WebSearch summary referencing AAN/AHS guideline content describes riboflavin as probably effective for migraine prevention (Level B), with 400 mg daily generally used in adults. In contrast, the Mayo Clinic source states that claims of effectiveness for migraine headaches have not been proven. This is not presented as a settled, unqualified benefit; discuss whether it is appropriate with a clinician. (3) (2)

Before taking riboflavin

Do not take / not appropriate for

  • Do not use a product if you have had a hypersensitivity reaction to riboflavin or an inactive ingredient in that specific product, unless a clinician advises otherwise. (all riboflavin products) (4)

Tell your clinician about

  • All medicines, supplements, and other ingested products you use, because no specific drug interaction data were confirmed in this research pass.
  • Alcoholism, burns, cancer, chronic diarrhea, fever, infection, intestinal disease, liver disease, thyroid disorders, serious injury, stress, or previous stomach-removal surgery, as these can increase riboflavin needs.
  • Pregnancy, plans for pregnancy, or breastfeeding.
  • Symptoms that may suggest deficiency, such as cracked lips, mouth inflammation, eye symptoms, or a sore tongue.
  • Whether you are considering riboflavin for migraine prevention, because source characterizations of its effectiveness differ.
(2) (3) (4)

How to take riboflavin

  • Use the exact product label and seek clinician or pharmacist advice if you are using riboflavin to treat suspected or confirmed deficiency.
  • For riboflavin deficiency, the treatment dose is determined by the prescriber for the individual according to the severity of deficiency; no single universal treatment dose was identified.
  • Riboflavin is also obtained from foods including fish, dairy, meat, and eggs.
  • Do not make treatment-dose changes without advice from the clinician responsible for your care.
(2) (1)

Procedures and treatment changes

Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (2)

Missed dose

No missed-dose instructions were established from the reviewed sources. Ask a pharmacist or clinician for advice based on why riboflavin is being used and the exact product.

Overdose

No tolerable upper intake level or riboflavin-specific overdose guidance was confirmed in this research pass. If too much may have been taken or symptoms develop, contact a poison-information service or clinician promptly.

Side effects

The primary effect reported in the reviewed Mayo Clinic source is a change in urine colour.

Bright yellow urine

What to notice: Urine may appear more yellow than normal, particularly with larger doses.

What to do: This is described as an expected, harmless effect and is not a cause for alarm. (2)

Possible deficiency or increased requirement

What to notice: Cracked lips, inflammation of the mouth, itching or burning eyes, sensitivity of the eyes to light, or a sore tongue.

What to do: Contact a clinician for assessment, particularly if symptoms persist or you have a condition that may increase riboflavin needs. (1) (2)

Serious warnings

Serious allergic or hypersensitivity reaction — emergency

Symptoms: Rash, hives, swelling of the face, lips, tongue, or throat, or difficulty breathing.

Action: Seek immediate medical attention. (4)

Interactions

Medicine or testEffectAction
Medicines and other supplementsNo specific drug interaction data were confirmed in this research pass. The reviewed Mayo Clinic source does not detail specific interactions.Tell healthcare providers about all medicines and supplements you take before using riboflavin. (2)

Pregnancy, breastfeeding, kidney/liver function, age

Children and adolescents

The reviewed Mayo Clinic source reports no pediatric problems with normal recommended amounts. For treatment of deficiency, a prescriber should determine the individual dose. (2)

Older adults

The reviewed Mayo Clinic source reports no geriatric problems with normal recommended amounts. (2)

Pregnancy and breastfeeding

The NIH ODS summary gives an RDA of 1.4 mg daily in pregnancy and 1.6 mg daily during lactation. The reviewed Mayo Clinic source describes risk during breastfeeding as minimal. Discuss supplements and individual nutritional needs with a clinician. (1) (2)

Monitoring

Before starting

  • Clarify whether riboflavin is being used for routine dietary intake, suspected deficiency, or migraine prevention.
  • Assess symptoms and factors that can increase riboflavin needs, including chronic diarrhea, intestinal disease, liver disease, thyroid disorders, alcohol use, and previous stomach-removal surgery.
  • Review all medicines and supplements, as specific interaction data were not confirmed in this research pass.

During treatment

  • For treatment of deficiency, reassess symptoms and the clinician-directed treatment plan.
  • If riboflavin is being considered for migraine prevention, reassess benefit and tolerability with a clinician because the reviewed sources characterize the evidence differently.
  • Recognise that more-yellow urine can be an expected, harmless effect, especially with larger doses.
(1) (2) (3)

Storage

Product-specific storage instructions were not established from the reviewed sources. Follow the storage directions on the exact supplement package and ask a pharmacist if uncertain.

Professional information

Clinician-facing context only. The primary NIH ODS fact sheet and the AAN/AHS guideline source were not directly fetched in this research pass; the relevant findings rely on WebSearch summaries. Use current primary sources and the exact product information.

United States

Indication: Routine dietary intake and deficiency treatment

Dose summary: The NIH ODS summary lists RDA values of 1.3 mg/day for men aged 19 years and older, 1.1 mg/day for women aged 19 years and older, 1.4 mg/day in pregnancy, and 1.6 mg/day in lactation. The reviewed Mayo Clinic source cites preventive RDA-range doses of 1.4-1.8 mg daily for adult/teen males, 1.2-1.3 mg daily for adult/teen females, 1.6 mg daily in pregnancy, 1.7-1.8 mg daily during breastfeeding, 1.2 mg daily for children aged 7-10 years, 1.1 mg daily for children aged 4-6 years, and 0.4-0.8 mg daily from birth through age 3 years. For deficiency treatment, the prescriber determines the dose based on severity; no universal treatment dose is given.

Renal context: Renal dosing guidance was not established from the reviewed sources. (1) (2)

All regions

Indication: Migraine prevention in adults

Dose summary: A WebSearch summary referencing AAN/AHS guideline content states that 400 mg daily is generally used for migraine prophylaxis in adults and describes riboflavin as probably effective (Level B). The Mayo Clinic source instead states that migraine claims have not been proven. Use current primary guideline material and clinical judgement; this is an unresolved difference in source characterization.

Renal context: Renal dosing guidance was not established from the reviewed sources. (3) (2)

Mechanism of action

Hepatic guidance

Liver disease can increase riboflavin needs according to the reviewed Mayo Clinic source. Hepatic impairment dosing guidance was not established from the reviewed sources.

Overdose note

No tolerable upper intake level or riboflavin-specific overdose guidance was identified in this research pass. (1) (2) (3)

Frequently asked questions

Why is my urine bright yellow after taking riboflavin?

Riboflavin may make urine look more yellow than usual, especially at larger doses. The reviewed Mayo Clinic source describes this as an expected and harmless effect. (2)

Can riboflavin prevent migraines?

The reviewed sources differ. A WebSearch summary referencing AAN/AHS guidance describes riboflavin as probably effective for migraine prevention, while the Mayo Clinic source says migraine claims have not been proven. Discuss the evidence and suitability for you with a clinician. (3) (2)

How much riboflavin do adults need each day?

The NIH ODS summary lists an RDA of 1.3 mg daily for men aged 19 years and older and 1.1 mg daily for women aged 19 years and older. Needs are higher in pregnancy and lactation. (1)

What is the mechanism of action of riboflavin?

Riboflavin is an essential water-soluble B vitamin and a component of FMN and FAD. These coenzymes have major roles in energy production, cellular function, growth and development, and metabolism of fats, drugs, and steroids. Riboflavin is needed to break down carbohydrates, proteins, and fats and to enable the body's use of oxygen. (1) (2) (3)

What is the generic name of Vitamin B2 (Riboflavin)?

The generic name is riboflavin. (1) (2)

What class of drug is riboflavin?

Vitamin B2 (Riboflavin) is classed as: Water-soluble B vitamin. (1) (2)

References

  1. Riboflavin - Health Professional Fact Sheet (summary via WebSearch)NIH Office of Dietary Supplements · United States · accessed 2026-08-05 · source 1
  2. Riboflavin (Oral Route) drug/supplement informationMayo Clinic · United States · accessed 2026-08-05 · source 2
  3. Riboflavin for migraine prophylaxis — AAN/AHS guideline summaryAAN/AHS guideline content (via WebSearch summary) · United States · accessed 2026-08-05 · source 3
  4. Standard allergic reaction warning for any ingested substanceStandard medical guidance (pharmacovigilance) · International · accessed 2026-08-05 · source 4
  5. PRENACORE (.BETA.-CAROTENE, ASCORBIC ACID, SODIUM ASCORBATE, CHOLECALCIFEROL, .ALPHA.-TOCOPHEROL ACETATE, DL-, THIAMINE MONONITRATE, RIBOFLAVIN, NIACINAMIDE, PYRIDOXINE HYDROCHLORIDE, FOLIC ACID, CYANOCOBALAMIN, AND FERROUS FUMARATE) TABLET [KREWE PHARMA, LLC] — US prescribing information (DailyMed SPL)U.S. National Library of Medicine (DailyMed) · US · accessed 2026-08-14 · source 5
  6. Riboflavin 5'-phosphate ophthalmic — patient drug information (MedlinePlus)U.S. National Library of Medicine (MedlinePlus) · US · accessed 2026-08-14 · source 6
  7. riboflavin — RxNorm normalized drug concept (RXCUI 1925821)U.S. National Library of Medicine (RxNorm) · US · accessed 2026-08-14 · source 7

Brand names by country

Single-ingredient riboflavin names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.

Priority countries

United States

  • Country LifeCountry Life
  • Douglas LaboratoriesDouglas Laboratories
  • Integrative TherapeuticsIntegrative Therapeutics
  • Life ExtensionLife Extension
  • BulkSupplements.comBulkSupplements.com
  • NutriCologyNutriCology
  • Axe & Sledge SupplementsAxe & Sledge Supplements
  • XYMOGENXYMOGEN
  • NOWNOW
  • MM Sports NutritionMM Sports Nutrition
View brands in additional countries.

This page provides general medicine information, not a diagnosis, nutrition assessment, prescription, individual supplement plan, migraine treatment plan, or substitute for a clinician, pharmacist, or current product information.

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