Supplement Label Index

Ferrous Fumarate vs. Iron Amino Acid Chelate

Among 1,931 on-market iron products with an identifiable primary form, 60.8% use Ferrous Fumarate (1,174 products) and 8.6% use Iron Amino Acid Chelate (167).

Ferrous FumarateIron Amino Acid Chelate
Quality tierUnratedTier 1
Iron by weight32.9%
Share of market60.8%8.6%
On-market products1,174167
Median declared dose18 elemental mg
middle half: 8–26
10 elemental mg
middle half: 5–18
Most common brandsDC, Wonder Laboratories, GNC Women's Ultra MegaNaturesPlus, 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 Fumarate is unrated

Widely marketed as comparably bioavailable to ferrous sulfate with less GI upset, but no comparative human absorption study was independently verified.

Source: uncertain -- needs review

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