Updated 28 September 2026: clarified the distinction between label wording, total-magnesium assays and chemical identity.
It means the magnesium is bonded to an amino acid, glycine in the case of magnesium glycinate, rather than sitting in the capsule as a simple mineral salt. "Bisglycinate" is the more precise name: two glycine molecules per magnesium ion.
The phrase on a label is not itself an analytical result. For a fully-chelated claim, ask what proportion is being claimed, on what basis, and which methods support it. An ingredient declaration, total-magnesium assay and chemical-identity test answer different questions.
What chelation actually does
A chelate wraps the mineral in an organic molecule. For magnesium bisglycinate, two glycine molecules bind the magnesium ion in a ring structure. The practical consequences are reasonably well established:
- Tolerability needs context. Dose, formulation and the individual matter; the term does not guarantee freedom from digestive effects.
- Interactions still matter. Do not assume that a chelated ingredient avoids medicine or nutrient interactions. Seek medicine-specific advice.
- Glycine is part of the ingredient. Its presence does not establish a sleep benefit at the dose in a particular product.
The 1994 head-to-head trial involved 12 patients with ileal resection. It found no overall absorption difference between diglycinate and oxide, a chelate advantage in four patients with the poorest absorption, and better reported tolerability. It does not establish absorption or tolerability equivalence in healthy adults or compare HealthyHey’s two products. Original trial.
Why wording alone is insufficient
Do not treat the words “fully chelated” or “100% chelated” as independent verification. Check the full ingredient declaration, supplier specification and appropriate identity evidence for the actual material. This article does not make a determination about a claim’s legal compliance.
This is not a hypothetical gap. Products marketed as fully chelated that were found to contain undeclared magnesium oxide have led to a recall in Canada and class action settlements in the United States.
The number that is checkable
Where the words are unregulated, the arithmetic is not. Magnesium bisglycinate has a molar mass of 172.42 g/mol against magnesium's 24.305 g/mol, which fixes its magnesium content at 14.1% by weight, at most. Hydrated commercial grades assay lower, roughly 11 to 13%.
Divide elemental magnesium by declared ingredient weight on the same serving and weight basis. A ratio materially above approximately 14.1%, if the declarations are accurate and uncertainty is considered, is inconsistent with pure anhydrous bisglycinate. It does not identify an extra source. A compatible ratio cannot rule out mixtures or establish full chelation.
Measured total magnesium, not measured chelation. Eureka report TR-26-EKA1-090488-02 records 14.01% total magnesium and 0.73 g/100 g moisture in submitted raw-material lot MG/GCN/010826. That result is compatible with bisglycinate composition, but does not prove chemical identity or the percentage chelated. It is not a finished-capsule potency result. Read the report and limitations.
Check the arithmetic. The magnesium label calculator compares label ratios with theoretical values. It is not an identity test and cannot determine a formula’s source split.
What a trustworthy label looks like
- It gives an elemental magnesium figure. Not just the compound weight. Without it you cannot dose or verify anything.
- It names every magnesium source in the ingredient list. One source or two, declared either way.
- Its arithmetic can be reconciled. Ask the manufacturer about inconsistent serving amounts or weight bases. Neither a compatible number nor a label claim replaces appropriate identity evidence.
- It has a third-party assay behind it. With the caveat below.
One thing lab reports cannot tell you
A total-magnesium assay measures the quantity in the sample tested, not the original chemical forms. An assay of raw material does not establish the potency of a finished retail serving. The three reports discussed on the 14% evidence page do not independently measure the product’s labelled 121 mg per two-capsule serving.
Ask an appropriate laboratory to propose complementary identity methods with references, controls and stated limitations. FTIR and powder X-ray diffraction can support interpretation for suitable materials, but a non-detect does not exclude every amorphous or low-level phase. A plausible glycine ratio or water-solubility result alone is not universal proof of percentage chelated. Read a supplier COA for its actual tests, not just its sample title.
Related reading: 22% vs 14% magnesium glycinate, and what the percentage actually means. Is buffered magnesium glycinate bad?
This article is educational and is not medical advice. Magnesium supplements are not intended to diagnose, treat, cure or prevent any disease. Consult a qualified healthcare professional before starting any supplement, particularly if you are pregnant, breastfeeding, have kidney disease, or take prescription medications. Percentages are calculated from standard atomic weights; commercial lots vary with moisture content.