Riboflavin 5'-phosphate
Riboflavin 5'-phosphate suppliers and sourcing guide
Riboflavin 5'-phosphate is the phosphate ester of riboflavin (vitamin B2), usually sold as its sodium salt, a yellow to orange-yellow, hygroscopic crystalline powder. It is made by phosphorylating riboflavin and then neutralizing, purifying and drying the product. It is far more water-soluble than riboflavin, so it is used in liquids, beverages and as a water-soluble yellow color; commercial material also contains some free riboflavin and other riboflavin phosphates.
- Category
- Vitamins and minerals
- Also known as
- Riboflavin 5'-phosphate sodium · Flavin mononucleotide (FMN) · Riboflavin sodium phosphate · E101(ii) · CAS 130-40-5
- Facts checked
- November 2026
Forms and grades of riboflavin 5'-phosphate
Suppliers sell different products under the same name. Specify the one you need.
Sodium salt, pharmacopeia grade
Riboflavin 5'-phosphate sodium tested to USP, Ph. Eur. or FCC monographs, for supplements and foods.
Supplement grade sold as FMN
The same compound marketed as flavin mononucleotide; compare the assay basis, since some specs state riboflavin content and others the phosphate salt.
Color grade
Grades made for yellow coloring in beverages, confectionery and dairy.
Premixes and triturations
Diluted or blended forms from premix suppliers for multivitamin and fortification use.
What to check on the COA
Compare each result with your own specification when the lot arrives.
- Assay
- Riboflavin content on a dried basis by HPLC or UV spectrophotometry, as set in the monograph.
- Free riboflavin and other phosphates
- Free riboflavin and riboflavin diphosphates by HPLC, which show how much of the material is the 5'-phosphate.
- Water
- Water by Karl Fischer or loss on drying, which matters because the salt is hygroscopic.
- Identity
- UV-visible spectrum or HPLC against a reference standard, plus a test for phosphate and sodium.
- Heavy metals
- Lead and other elemental impurities by ICP-MS.
- Microbiology
- Total aerobic count, yeast and mold and specified pathogens.
Storage, lots and expiry
Storage and shelf life
Riboflavin 5'-phosphate absorbs moisture and breaks down in light, so keep it tightly closed in light-proof containers in a cool, dry place. Suppliers set shelf life or a retest date, with assay and water as the usual retest checks.
Lots and expiry dates
Record assay basis, water and free riboflavin for each lot, since these change how much riboflavin each kilogram delivers. Rotate FEFO.
Regulatory status
Facts from regulators and standards bodies, each linked to its source.
21 CFR 184.1697 describes riboflavin-5'-phosphate (sodium) as prepared by phosphorylation of riboflavin and affirms it as GRAS as a nutrient supplement in milk products.
Source: ecfr.gov (opens in a new tab)Health Canada's Multi-Vitamin/Mineral Supplements monograph lists riboflavin 5'-phosphate sodium as a source ingredient for riboflavin (vitamin B2).
Source: webprod.hc-sc.gc.ca (opens in a new tab)FDA's Substances Added to Food inventory lists riboflavin 5'-phosphate, sodium with the technical effect "nutrient supplement" and cites 21 CFR 184.1697.
Source: hfpappexternal.fda.gov (opens in a new tab)
This is general information, not regulatory advice. Status differs by country and by how the ingredient is used, so check the rules for your product and market.
Riboflavin 5'-phosphate suppliers
Manufacturers and distributors whose own websites say they sell it.
We are checking riboflavin 5'-phosphate suppliers now
Every listing is checked against the supplier’s own website before it goes live, so this list fills in over the coming weeks. The specs and COA checklist above are ready today.
Sell riboflavin 5'-phosphate? Request a listingFrequently asked questions
What forms of riboflavin 5'-phosphate can brands buy?
Common forms include sodium salt, pharmacopeia grade, supplement grade sold as FMN, color grade and premixes and triturations. Ask each supplier for the specification sheet of the exact grade they quote.
What should the COA for riboflavin 5'-phosphate include?
Expect assay, free riboflavin and other phosphates, water, identity, heavy metals and microbiology, each with its method, specification and result for that lot.
How should riboflavin 5'-phosphate be stored?
Riboflavin 5'-phosphate absorbs moisture and breaks down in light, so keep it tightly closed in light-proof containers in a cool, dry place. Suppliers set shelf life or a retest date, with assay and water as the usual retest checks.
What is the regulatory status of riboflavin 5'-phosphate?
21 CFR 184.1697 describes riboflavin-5'-phosphate (sodium) as prepared by phosphorylation of riboflavin and affirms it as GRAS as a nutrient supplement in milk products. Health Canada's Multi-Vitamin/Mineral Supplements monograph lists riboflavin 5'-phosphate sodium as a source ingredient for riboflavin (vitamin B2). FDA's Substances Added to Food inventory lists riboflavin 5'-phosphate, sodium with the technical effect "nutrient supplement" and cites 21 CFR 184.1697.
More vitamins and minerals
- Magnesium GlycinateMagnesium bisglycinate · Magnesium bisglycinate chelate
- Vitamin CL-ascorbic acid · Ascorbic acid
- Vitamin D3Cholecalciferol · Colecalciferol
- ZincZinc citrate · Zinc gluconate
- Vitamin A palmitateRetinyl palmitate · Retinol palmitate
- Vitamin A acetateRetinyl acetate · Retinol acetate
- Beta-caroteneβ-Carotene · all-trans-beta-carotene
- Vitamin D2Ergocalciferol · Calciferol
- Vitamin E (d-alpha tocopherol)d-alpha-tocopherol · RRR-alpha-tocopherol
- Mixed tocopherolsTocopherols concentrate, mixed · Mixed tocopherol concentrate
- Vitamin K1Phylloquinone · Phytonadione
- Vitamin K2 (MK-7)Menaquinone-7 · MK-7
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