Why does it turn urine yellow?

That's harmless — the bright color is excess riboflavin being excreted.

Is it safe at high doses?

Generally yes; it's water-soluble with low toxicity, and excess is excreted.

Vitamin B2 (Riboflavin): Benefits, Dosing & Evidence

What it is

Riboflavin is a B vitamin central to energy production and antioxidant function. It's found in dairy, eggs, and greens, and gives supplements and urine a bright yellow color.

How it works

Riboflavin (B2) is central to energy production and to recycling the body's antioxidant systems. At higher doses it's thought to support mitochondrial energy in a way that may help prevent migraines.

What it's been studied for

Used to support energy metabolism and, at higher doses, studied for migraine prevention.

What the evidence shows

Beyond correcting deficiency (uncommon), riboflavin has some evidence at higher doses for reducing migraine frequency, though results vary. General energy claims apply only if you were low.

Who should consider it

Deficiency is uncommon. Beyond correcting a shortfall, its main studied use is higher-dose migraine prevention. It's a standard component of B-complex products.

Amounts commonly studied

Daily needs are small (around 1.1-1.3 mg); migraine studies use much higher amounts under guidance.

How to take it

Daily needs are small (1.1-1.3 mg); migraine studies use much higher amounts under guidance. It's water-soluble and harmlessly turns urine bright yellow.

Forms & absorption

Riboflavin or riboflavin-5-phosphate (the active form). Common in B-complexes.

Food sources

Dairy, eggs, lean meats, almonds, and green vegetables; also fortified grains.

Safety & interactions

Very safe; harmlessly turns urine bright yellow. Few interactions.

Myths & what it won't do

Myth: yellow urine means the vitamin is 'working.' Reality: it just means you're excreting the excess riboflavin. Myth: it energizes healthy people. Reality: only relevant if you were low, aside from the migraine-prevention use.

Common questions

Does riboflavin help migraines?: Higher doses have some evidence for reducing migraine frequency, though results vary — it's used as a preventive, not a quick fix.
Why does it turn urine yellow?: That's harmless — the bright color is excess riboflavin being excreted.
Is it safe at high doses?: Generally yes; it's water-soluble with low toxicity, and excess is excreted.

The amounts listed here are what published research has used — not a prescription or a recommended dose for you. Confirm anything you plan to take with your own healthcare provider, especially if you take medications, are pregnant or nursing, or have a health condition.

Vitamin B2 (Riboflavin)