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Vitamin

Riboflavin-5-Phosphate

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Riboflavin-5-Phosphate. Active form of B2 — used directly as FMN without liver conversion.

How it works. Direct FMN precursor for flavoprotein enzymes; cofactor for MTHFR.

What the research supports. 1 graded claims. Strongest: Migraine prophylaxis (high-dose) (moderate).

How much to take. Typical dose: 10–25 mg.

Side effects and interactions. 1 medication interaction listed. No serious side effects listed at normal doses.

Stacking. Pairs well with Omega-3 (EPA/DHA), Alpha-GPC or CDP-choline.

Common forms. Available as Capsule or softgel, Sublingual tablet or liquid, Methylated active form for sensitive individuals, Multivitamin matrix.

Key studies. 8 studies cited. The strongest are listed with links to PubMed.

Community. Experiences from people who have tried Riboflavin-5-Phosphate. Anecdotes are not medical advice.

Riboflavin-5-Phosphate. Active form of B2 — used directly as FMN without liver conversion.

Molecular structureC17H21N4O9P · 456.3 g/mol

What it is

Active form of B2 — used directly as FMN without liver conversion.

Food sources

Whole-food sources (animal products for fat-soluble and B-complex vitamins; produce for water-soluble vitamins)Fortified foods (cereals, dairy, plant milks, nutritional yeast)Multivitamins or stand-alone supplements in synthetic or food-derived form

Goals

Energy ProductionBrain & Cognitive

How it works

Direct FMN precursor for flavoprotein enzymes; cofactor for MTHFR.

Pathways

  • FMN/FAD redox
  • MTHFR activation

Effects

  • +Migraine prophylaxis (high-dose) supports

What the research supports

Migraine prophylaxis (high-dose)moderate

Strong: consistent results across large trials or meta-analyses. Moderate: several trials, mostly positive. Limited: small or mixed studies. Preclinical: animal or cell research only.

Typical dose
10–25 mg
TimingConsistent daily timing recommended; split larger doses if GI tolerance is a concern.
With foodOptional
Best formMost evidence is based on the capsule or softgel form.
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Side effects & interactions

Common side effects

  • Bright yellow urine

Medication interactions

Prescription medications (general)minor

Always disclose Riboflavin-5-Phosphate use to your prescriber — additive, antagonistic, or pharmacokinetic interactions are possible.

Check any supplement–medication combination with your pharmacist before starting.

Combines with

Pairs well

  • Omega-3 (EPA/DHA)Membrane fluidity and neuronal signaling support.
  • Alpha-GPC or CDP-cholineProvides choline substrate for acetylcholine synthesis.

Common forms

  • Capsule or softgel
  • Sublingual tablet or liquid
  • Methylated active form for sensitive individuals
  • Multivitamin matrix

Key studies

8 studies cited in total.

PubMed: Riboflavin-5-Phosphate — Migraine prophylaxis ↗
Systematic review · PubMed (NLM) · 2026

Opens current human and preclinical literature matching Riboflavin-5-Phosphate and "Migraine prophylaxis". Filter by RCT, meta-analysis, or year on the results page.

PubMed: Riboflavin-5-Phosphate — randomized controlled trial ↗
Systematic review · PubMed (NLM) · 2026

Opens current human and preclinical literature matching Riboflavin-5-Phosphate and "randomized controlled trial". Filter by RCT, meta-analysis, or year on the results page.

PubMed: Riboflavin-5-Phosphate — meta-analysis ↗
Systematic review · PubMed (NLM) · 2026

Opens current human and preclinical literature matching Riboflavin-5-Phosphate and "meta-analysis". Filter by RCT, meta-analysis, or year on the results page.

Discussion

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