Vitamin B2 (Riboflavin)

riboflavin · vitamin B2 · riboflavin-5'-phosphate

Snapshot

Indications	Contraindications
Migraine prevention¹ Pediatric migraine prevention² Riboflavin transporter deficiency^3–5 Inherited flavin disorders⁶ Riboflavin deficiency⁷

Riboflavin (vitamin B2) is a water-soluble vitamin that serves as the precursor of the coenzymes flavin mononucleotide and flavin adenine dinucleotide, which carry energy production and metabolism⁷. Supplementation follows from that role in mitochondrial function.^{6, 8} It is used for migraine prevention, for riboflavin transporter deficiency and related inherited flavin disorders, and for correcting low status^{6, 8}. It is also studied for blood pressure in people with a common methylenetetrahydrofolate reductase (MTHFR) variant⁹. Vegans, people who eat little dairy, and pregnant or lactating women with low meat and dairy intake carry the greatest risk of inadequacy⁷.

For adult migraine prevention, a dose-response meta-analysis found fewer attacks, and the American Academy of Neurology rated riboflavin probably effective⁷. Pediatric evidence is less settled, with systematic reviews pointing toward fewer attacks but a headache review calling pediatric use unproven^{2, 10, 11}. A 2025 scoping review found the MTHFR variant interacted with riboflavin supplementation on blood pressure, though a Cochrane review rated that evidence very uncertain. Products listing riboflavin are numerous, mostly as free riboflavin and sometimes as riboflavin 5'-phosphate; see Form comparison⁷.

The pills carry no contraindication because the sources name none.⁷ The Food and Nutrition Board set no upper intake level, and the National Institutes of Health Office of Dietary Supplements lists no clinically relevant medication interactions⁷. LiverTox rates it an unlikely cause of clinically apparent liver injury¹².

Last updated October 15, 2026. Read how we make monographs.

In the full monograph

60 sources, 47 studies

When to useThe situations practitioners use it for, each with the reason and the study behind it.
SafetyWho should avoid it, who needs extra care, and the side effects reported in studies.
InteractionsThe medicines and supplements it interacts with, the effect of each, and what labeling says to watch.
Protocol notesThe doses used in studies, how and when they were taken, and how the forms on the market compare.
How it worksWhat it is and how it works in the body, in plain terms.
Published studiesThe studies behind each use, popular claims checked against them, and trials still under way.
Word of mouthWhat patients and practitioners report online, kept separate from the clinical evidence.
Clinical perspectiveA closing read of where the evidence is solid, where it is thin, and what has not been studied.

Snapshot

In the full monograph

Sources