Supplement Label Index

Magnesium Aspartate vs. Magnesium Amino Acid Chelate

Among 6,062 on-market magnesium products with an identifiable primary form, 8.2% use Magnesium Aspartate (500 products) and 4.6% use Magnesium Amino Acid Chelate (279).

Magnesium AspartateMagnesium Amino Acid Chelate
Quality tierUnratedTier 2
Magnesium by weight8.4%—
Share of market8.2%4.6%
On-market products500279
Median declared dose76 elemental mg
middle half: 40–167.5
83 elemental mg
middle half: 25–175
Most common brandsBluebonnet, Douglas Laboratories, PS ProSuppsNaturesPlus, Douglas Laboratories, MH Michael's Health Naturopathic Programs

Doses are declared per serving in elemental mg. “By weight” is the share of the ingredient that is the nutrient itself (e.g. elemental magnesium in a magnesium salt).

Why Magnesium Aspartate is unrated

No head-to-head human bioavailability study specific to this salt was found.

Source: none located -- no human head-to-head study found (a rat stable-isotope study including aspartate exists: Coudray C et al. 2005, Magnes Res 18(4):215-23, PMID 16548135; not read in full)

Why Magnesium Amino Acid Chelate is tier 2

Lower serum and salivary Mg response than citrate (but greater 24-h urinary Mg than oxide) in one 60-day RCT; "amino acid chelate" is not a single defined compound.

Source: Walker AF et al. 2003, Magnes Res 16(3):183-191, PMID 14596323

Tiers summarize published comparative bioavailability or outcome evidence for each form (see methodology). This page describes the market; it is not a recommendation to take either form. Talk to a clinician about what's right for you.

Other magnesium comparisons