Supplement Label Index

Ferrous/Iron Bisglycinate Chelate vs. Iron Amino Acid Chelate

Among 1,931 on-market iron products with an identifiable primary form, 15.2% use Ferrous/Iron Bisglycinate Chelate (293 products) and 8.6% use Iron Amino Acid Chelate (167).

Ferrous/Iron Bisglycinate ChelateIron Amino Acid Chelate
Quality tierTier 1Tier 1
Iron by weight27.4%
Share of market15.2%8.6%
On-market products293167
Median declared dose10 elemental mg
middle half: 6–18
10 elemental mg
middle half: 5–18
Most common brandsBluebonnet, Solgar, MegaFoodNaturesPlus, 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 Ferrous/Iron Bisglycinate Chelate is tier 1

Apparent bioavailability 90.9% vs. 26.7% for ferrous sulfate in a pediatric iron-deficiency-anemia RCT; only the chelate group showed a significant ferritin increase.

Source: Pineda O, Ashmead HD. 2001, Nutrition 17(5):381-384, PMID 11377130

Why Iron Amino Acid Chelate is tier 1

If equivalent to ferrous bisglycinate chelate, showed substantially higher apparent bioavailability than ferrous sulfate.

Source: Pineda O, Ashmead HD. 2001, Nutrition 17(5):381-384, PMID 11377130

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 iron comparisons