# The Food Supplements Purity Criteria (Magnesium L-threonate monohydrate) (England) Regulations 2026, Schedule: PURITY CRITERIA FOR MAGNESIUM L-THREONATE MONOHYDRATE


Synonym
Magnesium L-threonate
Definition
Chemical name
Magnesium (2R,3S)-2,3,4-trihydroxybutanoate monohydrate
CAS number
500304-76-7
Chemical formula
C 8H 16MgO 11
Molecular weight
312.51 Da
Colour (solid)
White
Assay
Magnesium: 7.2% to 8.3%
L-threonate: 82% to 91%
Description
A water-soluble white powder which is manufactured via a chemical synthetic process.
Identification
Solubility
Soluble in water at 1% concentration at 25℃ and that is clear in solution at 1% concentration.
pH USP (1% in H₂O)
5.8 to 7.0
Purity
Loss on drying
Not more than 5.0% (105℃/4 hours)
Oxalic acid/oxalate
Not more than 0.5% (as oxalic acid)
Arsenic
Not more than 1 ppm
Lead
Not more than 0.5 ppm
Cadmium
Not more than 0.2 ppm
Mercury
Not more than 0.1 ppm

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Source: https://www.legislation.gov.uk/ukdsi/2026/9780348282573/schedule (the official version)
Page: https://openlegislation.uk/draft-food-supplements-purity-criteria-magnesium-l-threonate-monohydrate-england-regulations-2026/schedule
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.