Vitamin B2

Vitamin B2, better known as riboflavin, is a water-soluble B vitamin. Your body turns it into two helper molecules, FMN and FAD, which work inside cells to release energy from food. Riboflavin contributes to normal energy-yielding metabolism and to the reduction of tiredness and fatigue. It also contributes to the maintenance of normal skin, vision, mucous membranes and red blood cells, to normal iron metabolism and to the protection of cells from oxidative stress.

Your body cannot store riboflavin, so daily intake matters. NHS guidance puts adult needs at about 1.1 mg for women and 1.3 mg for men, usually covered by milk, eggs, wholegrains, mushrooms and green vegetables. One practical detail: UV light breaks riboflavin down. Milk left in sunlight loses some of it, and the same applies to packaging, so we favour opaque or dark pots. Riboflavin also sits in nearly every B-complex, so it is worth checking our full vitamin B range before you add a separate product.

Free riboflavin and riboflavin-5-phosphate are not the same on the label

Most tablets and capsules contain plain riboflavin, in strengths from around 1.4 mg, the EU reference intake printed on labels, up to 100 mg or more. Your body converts this into riboflavin-5-phosphate, the active form it actually uses. Some products supply that active form directly, which suits people who prefer to skip the conversion step. In healthy adults there is no proof that one form outperforms the other, and both count towards the same daily intake. Riboflavin is also needed to activate vitamin B6, which is why you often see the two together in the products with vitamin B6 we carry.

How we choose the vitamin B2 we stock

We judge three things: the form, the dose and the combination. For everyday use we prefer straightforward riboflavin close to the daily reference amount, because that is what most diets are short of. We keep riboflavin-5-phosphate for people who want the pre-converted form, and we say so instead of calling it better. Higher strengths stay in the range, with a clear note on who they are for. We buy directly from the brands, so the label matches the pot, and every product passes our compliance team before it goes live. We test ourselves and independent labs spot-check batches. See how we select brands and products.

Who a separate B2 product suits

A standalone riboflavin supplement makes sense if your diet is low in dairy and eggs, if you eat strictly plant-based, or if a GP or dietitian has told you your intake is low. If you want broader cover, a B-complex or multivitamin is usually the more sensible buy. Many people who feel tired start with supplements for daily energy. Riboflavin only helps there when your intake is genuinely short, so expect a steady difference over weeks rather than a same-day lift.

Two honest notes. Bright yellow urine is normal at higher strengths: it is unused riboflavin leaving the body, not a sign the product failed. And 400 mg tablets are sold in the UK. The NHS states there is not enough evidence about the effects of high daily doses, and that 40 mg or less a day is unlikely to cause harm. Keep those high strengths for use alongside a healthcare professional, and choose a modest daily amount for general intake.