Magnesium Is Not Magnesium.
The Truth Your Supplement Label Doesn’t Tell You.
Glycinate. Bisglycinate. Citrate. Oxide. L-Threonate. They all contain magnesium—but they do not deliver the same amount, behave the same way in a formulation, or have the same evidence behind their claims.
The number most magnesium labels make easy to miss
mg elemental MgNot the weight of the magnesium salt. Not the marketing headline. This is the number to compare first.
~8.3% Approximate theoretical elemental magnesium in anhydrous magnesium L-threonate
First: stop comparing the wrong number.
“1,000 mg magnesium” can mean 1,000 mg of a magnesium compound—not 1,000 mg of elemental magnesium.
Elemental Mg %
Atomic mass of Mg ÷ molecular mass of the magnesium compound × 100.
Theoretical ≠ COA
Hydration, purity, buffering and commercial specifications can change the actual assay.
Use the COA
For an actual product, calculate from the supplier’s current elemental-magnesium specification.
The Magnesium Salt Atlas
Approximate theoretical values. Commercial raw materials can differ. Always verify the current specification and COA.
| Magnesium Salt | Approx. Elemental Mg | Compound for 100 mg Mg | Formulation Signal |
|---|---|---|---|
| Magnesium Oxide | 60.3% | ~166 mg | Very high Mg density; comparatively poor bioavailability versus several soluble forms |
| Magnesium Hydroxide | 41.7% | ~240 mg | High elemental density; GI/osmotic behaviour matters |
| Magnesium Carbonate | 28.8% | ~347 mg | Acid-dependent chemistry |
| Magnesium Chloride | ~25.5% | ~392 mg | Highly soluble; hydration state changes elemental % |
| Magnesium Sulfate | ~20.2% | ~495 mg | Distinct salt; not interchangeable with other forms |
| Trimagnesium Citrate | ~16.2% | ~619 mg | Strong comparative human bioavailability history |
| Magnesium Malate | ~15.3% | ~652 mg | Commercial specifications can vary |
| Magnesium Bisglycinate | ~14.1% | ~709 mg | Popular daily-use form; verify actual assay and grade |
| Magnesium Lactate | ~12.0% | ~833 mg | Organic salt with human absorption data |
| Magnesium L-Threonate | ~7.2–8.3% | ~1,200–1,390 mg | Low Mg density; distinctive CNS research programme |
Same 100 mg elemental magnesium.
Very different amounts of powder.
Then the chemistry meets biology.
Your body does not ultimately care about an influencer’s ranking of salts. It regulates magnesium as Mg²⁺ within a tightly controlled physiological system.
Compound + ligand
pH + water + food matrix
Available magnesium chemistry
Paracellular + TRPM6/TRPM7-associated pathways
Cells + tissues + bone
Conservation ↔ Excretion
Why “chelated = best” is too simple.
What the human evidence actually says.
Strong comparative story
Human studies generally find citrate and several soluble/organic forms more bioavailable than oxide under specific study conditions.
Useful—but don’t mythologize it.
It is a rational and popular formulation choice. “Chelated” does not automatically prove superior clinical efficacy for every outcome.
Most interesting CNS story.
Human cognition and sleep studies are promising, but the evidence base is still emerging and does not establish universal superiority.
“The best magnesium” is an incomplete question. Best for what?
Four different magnesium optimization problems.
Now the Indian question:
“Is it FSSAI approved?”
That sentence is too vague to be scientifically or regulatorily useful.
01 — Ingredient Identity
Check the exact magnesium salt—not merely “magnesium”.
02 — Regulatory Route
Specified and non-specified ingredients can follow different regulatory pathways.
03 — Current Status
Verify the current FSSAI record, specification, category and applicable conditions.
The 30-Second Magnesium Label Audit.
01. Find elemental Mg
Ignore the big salt-weight headline until you find the actual magnesium amount.
02. Identify the salt
Glycinate, citrate, oxide, L-threonate, chloride—or a blend?
03. Check the serving
Compare products on elemental Mg per serving, not grams of compound.
04. Look for transparency
Assay, specification and formulation transparency are stronger signals than “premium” language.
05. Match the objective
General supplementation, GI use, electrolyte formulation and CNS research are different jobs.
06. Respect safety
Supplemental magnesium can cause GI effects. Kidney impairment and medicine interactions require particular caution.
The conclusion nobody needs another influencer to tell them.
Magnesium is not a popularity contest between glycinate, citrate and L-threonate.
It is a formulation and physiology problem involving:
Chemical form × elemental dose × dissolution × intestinal transport × baseline status × tissue handling × clinical evidence × safety × regulation