The number on the label is not the number on the bag
Magnesium bisglycinate is a chelate: magnesium bound to two molecules of the amino acid glycine. The powder weighs more than the magnesium it contains. Our magnesium bisglycinate carries about 20% elemental magnesium, which means 20 g of magnesium in every 100 g of powder.
Labels in the EU declare the amount of the element, not the weight of the salt. Dosing by salt weight overstates the magnesium in the product, so check the basis before you write the formula.
The calculation
Take a target of 100 mg of elemental magnesium per dose and a powder at 20% elemental magnesium:
- Powder needed: 100 ÷ 0.20 = 500 mg of bisglycinate per dose.
If the specification says 12% magnesium, the same target needs 100 ÷ 0.12 = 833 mg. The two grades are not interchangeable at the same weight, which is why the grade must be written into the specification.
What to check on the specification
1. The elemental magnesium percentage and the method used to measure it. 2. The chelate form: bisglycinate, not a mixture with other magnesium salts. 3. The batch range on the certificate of analysis. 4. The packaging and the minimum lot size. 5. The storage conditions, because magnesium powders absorb moisture.
A specification that gives only the weight of powder and no elemental content cannot be checked against the label.
Formulation for tablets and capsules
For tablets, the bulk density of the powder changes the size of the tablet. For capsules, the fill weight per size changes with the density as well. Run a sample with the final blend before you commit to a production run, and check the flow and the disintegration of the product. Our formula calculator estimates fill weights per capsule and helps you compare the grades.
Claims and regulation
Keep label claims within what the ingredient and EU rules allow. A statement about magnesium should refer to the authorised wording for magnesium, and any further claim needs review by a regulatory consultant before it goes on pack.
Next step
Tell us the elemental dose, the format and the quantity. We reply with prices and documents within one hour on business days, and you can request a sample to check the powder in your blend.