The price per kilo is the wrong comparison
Magnesium is sold as many different salts, and the weight of each salt is not the weight of magnesium it delivers. Magnesium citrate, malate, taurate and bisglycinate all supply magnesium, but a gram of each contains a different amount of the element. An offer that looks cheaper per kilo can deliver less magnesium per dose, and a label that states the wrong basis can mislead the consumer.
Our range includes magnesium citrate, magnesium malate and magnesium taurate. The certificate of analysis for each lot states the assay, and the magnesium content should be read from it, not estimated from the salt name.
Elemental magnesium: the figure that matters
Elemental magnesium is the amount of magnesium ion in the salt. It is the figure to use for labelling and for comparing offers. To find it, multiply the salt weight by the magnesium fraction of the salt, and by the assay if the assay is below 100%. The magnesium fraction is fixed by the chemistry: a salt with a larger molecule carries less magnesium per gram.
Work it through in this order:
1. Take the assay of the salt from the certificate, for example 98%. 2. Multiply the salt weight by the assay to get the active salt weight. 3. Multiply the active salt weight by the magnesium fraction of that salt. 4. Compare offers on elemental magnesium per 100 g of powder.
What to check on each specification
- The stated basis: some sheets give elemental magnesium directly, others give the salt weight only. Ask which one you are buying.
- The assay range: a minimum assay guarantees the lower end of the magnesium content, not a typical figure.
- Hydration state: a hydrated salt weighs more per mole of magnesium than an anhydrous one. Check the form on the certificate.
- Moisture: a hygroscopic powder can gain weight on the shelf, which lowers the magnesium per gram over time.
Why the choice affects the label
The label must state the magnesium per serving, normally as elemental magnesium and as a percentage of the reference intake. A formula built on the salt weight instead of the elemental weight will carry too little magnesium for the claim, or too much if the calculation is reversed. Build the dose from the elemental figure from the start, and use the same figure in the specification and the label.
A simple checklist
1. Confirm the salt and its hydration state on the certificate. 2. Confirm the assay and the batch range. 3. Calculate elemental magnesium per 100 g for each offer. 4. Compare the cost per gram of elemental magnesium, not per kilo of salt. 5. Ask for the certificate of analysis and a sample before you commit.
Next step
Tell us the salt you prefer, the elemental dose per serving and the format. We reply with the elemental content per lot, prices and documents within one hour on business days. You can also request a sample and test the powder in your formula.