GradedHealth

Riboflavin (vitamin B2)

Last reviewed October 2026 · Based on 11 studies

Bottom line

Riboflavin (vitamin B2) may reduce how often adults get migraines: 400 mg a day cut attacks in a small placebo-controlled trial. The evidence is limited, children's results were mixed, and combination supplements did not clearly beat placebo.

What it helps with

  • Reduces migraine attacks in adults — Benefit, evidence grade C (Limited). One small placebo-controlled adult trial (55 people) plus meta-analyses with high heterogeneity; downgraded for inconsistency and small trials.
  • Prevents migraines in children — Mixed results, evidence grade C (Limited). Two small placebo-controlled trials found no clear effect, while a vote-count review found benefit; small, inconsistent evidence.
  • Prevents migraines when combined with magnesium, feverfew or CoQ10 — No effect, evidence grade C (Limited). Two small trials of combination products, not riboflavin alone; no significant difference from placebo on migraine days; indirect evidence.

What it is

Riboflavin is vitamin B2, a B vitamin sold as a supplement [1]. Migraine studies used it as a supplement at doses of 50 mg to 400 mg a day [2][3].

How it might work

Proposed mechanism: migraine may involve reduced energy metabolism in brain cells, and riboflavin may improve mitochondrial energy efficiency. This is a proposal from the trial authors, not a proven effect [2][4].

What the research says

In a 3-month trial of 55 adults, 400 mg a day lowered attack frequency and headache days compared with placebo; 59% of people on riboflavin had at least a 50% drop in headache days, against 15% on placebo [2]. A 2022 meta-analysis of eight randomised trials and one controlled trial (673 participants) found reductions in migraine days, duration, frequency and pain, but heterogeneity was high [4]. A 2025 dose-response meta-analysis found a mean difference of −1.34 in attack frequency for riboflavin [5]. In children, two placebo-controlled trials found no clear benefit [6][3]. Combination products with magnesium, feverfew or CoQ10 did not clearly reduce migraine days compared with placebo [7][8].

Doses used in studies

Adults: 400 mg a day for three months [2]. Children: 200 mg a day in one trial [6] and 50 mg a day in another, with 16-week treatment periods [3]. Combination products contained 400 mg of riboflavin with magnesium and feverfew [7], or riboflavin with magnesium and CoQ10 [8].

Safety and interactions

Common side effects were minor. In the adult trial, there were two adverse events on riboflavin (diarrhea and increased urination) and one on placebo (abdominal cramps), none serious [2]. A 2017 systematic review described adverse reactions as generally mild [9]. No upper intake limit or toxic dose is given in the studies read for this page, so this page cannot say what dose would be harmful [2][6][9]. The abstracts read did not report results for pregnancy, breastfeeding, kidney or liver disease, or medicine interactions. The 2017 review notes that riboflavin's pharmacokinetic and pharmacogenomic effects still need study [9]. Anyone pregnant, breastfeeding, with kidney or liver disease, or taking other medicines should ask a doctor before using riboflavin for migraine [9][2].

Caveats and open questions

The adult benefit rests on one trial of 55 people [2], and the wider meta-analyses pool trials that differ in dose, age and design [4][9]. The paediatric findings conflict, with a vote-count review positive and two placebo-controlled trials negative [1][6][3]. Placebo response in children was high [6]. Trials of riboflavin alone in larger, longer studies are needed [9].

References

  1. Systematic Review Suggests Nutraceuticals Containing Vitamin B2 Could Provide an Alternative Treatment for Paediatric Migraines.. Acta Paediatr, 2025.
  2. Effectiveness of high-dose riboflavin in migraine prophylaxis. A randomized controlled trial.. Neurology, 1998.
  3. Medium-dose riboflavin as a prophylactic agent in children with migraine: a preliminary placebo-controlled, randomised, double-blind, cross-over trial.. Cephalalgia, 2010.
  4. Effect of Vitamin B2 supplementation on migraine prophylaxis: a systematic review and meta-analysis.. Nutr Neurosci, 2022.
  5. Effects of selected dietary supplements on migraine prophylaxis: A systematic review and dose-response meta-analysis of randomized controlled trials.. Neurol Sci, 2025.
  6. High-dose riboflavin for migraine prophylaxis in children: a double-blind, randomized, placebo-controlled trial.. J Child Neurol, 2008.
  7. A combination of riboflavin, magnesium, and feverfew for migraine prophylaxis: a randomized trial.. Headache, 2004.
  8. Improvement of migraine symptoms with a proprietary supplement containing riboflavin, magnesium and Q10: a randomized, placebo-controlled, double-blind, multicenter trial.. J Headache Pain, 2015.
  9. Prophylaxis of migraine headaches with riboflavin: A systematic review.. J Clin Pharm Ther, 2017.