Supplement Label Index

Magnesium Glycinate vs. Magnesium Aspartate

Among 6,062 on-market magnesium products with an identifiable primary form, 9.5% use Magnesium Glycinate (573 products) and 8.2% use Magnesium Aspartate (500).

Magnesium GlycinateMagnesium Aspartate
Quality tierTier 1Unrated
Magnesium by weight14.1%8.4%
Share of market9.5%8.2%
On-market products573500
Median declared dose100 elemental mg
middle half: 28.2–185
76 elemental mg
middle half: 40–167.5
Most common brandsMetagenics, Metabolic Maintenance, KALBluebonnet, Douglas Laboratories, PS ProSupps

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 Glycinate is tier 1

Marketed and studied as a gentler, well-absorbed chelate; showed greater clinical symptom improvement than oxide in a comparative RCT.

Source: Walker AF et al. 2003, PMID 14596323

Why Magnesium Aspartate is unrated

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

Source: uncertain -- needs review

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