Magnesium Label Math & Price-per-100mg Calculator

Magnesium Label Math & Price-per-100mg Calculator

Supplement labels often display large numbers on the front of the bottle—like 1,000 mg or 1,500 mg—that represent the total weight of the chemical compound (the magnesium bound to glycine, citric acid, or malic acid). What your body actually absorbs, however, is the elemental magnesium yield.

Additionally, some manufacturers use "buffering tricks" by mixing cheap Magnesium Oxide into premium chelates to inflate elemental yield figures. Use this calculator to verify the math on your supplement panel, calculate your true cost per 100 mg of elemental magnesium, and detect mislabeled products.

⚠️ Transparency Notice: This calculator uses standard stoichiometry and molecular weight ratios to evaluate supplement labels. It is for informational and consumer audit purposes and does not substitute medical advice.

Supplement Label Auditor & Cost Calculator

Determine exact elemental yields, calculate cost per active dose, and identify label discrepancies.

Theoretical Max Elemental
0 mg
Cost / 100mg Elemental
$0.00
Label Integrity Rating
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Label Integrity Audit
Value Analysis

Frequently Asked Questions

What is "Buffered" Magnesium Glycinate? +
Buffered magnesium is a blend where the manufacturer mixes pure Magnesium Glycinate with inexpensive Magnesium Oxide. Brands do this to increase the elemental magnesium number on the back panel while keeping pill sizes smaller, but it reduces the overall bioavailability of the product.
Why does 1,000 mg of Magnesium Bisglycinate only give ~140 mg of Magnesium? +
Magnesium Bisglycinate consists of one elemental magnesium atom bound to two glycine amino acid molecules. Because glycine makes up ~86% of the molecule's total weight, elemental magnesium accounts for only ~14.1% of the overall compound weight.
How do I know if a supplement price per dose is fair? +
A fair price for fully chelated Magnesium Bisglycinate generally falls between $0.05 and $0.12 per 100 mg of pure elemental magnesium. Prices significantly higher than $0.15 per 100 mg of elemental yield often indicate marked-up brand positioning.

Literature & Analytical Methodologies

  1. DiSilvestro, R. A., et al. (2013). Magnesium glycinate supplementation in healthy adults. FASEB Journal, 27(S1), 1107-4.
  2. Siebrecht, S. (2013). Magnesium Bisglycinate: Bioavailability and Tolerance. OM & Nutrition, 144, 1-16.
  3. Coudray, C., et al. (2005). Study of magnesium bioavailability from ten organic and inorganic Mg salts in Mg-depleted rats using a stable isotope approach. Magnesium Research, 18(4), 215-223.

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