Ferrous Gluconate
Ferrous Gluconate is a unrated form of Iron, used in 138 on-market products and providing 11.6% elemental iron by weight.
138
on-market products
unrated
quality tier
11.6%
elemental fraction
Basis: Fe(C6H11O7)2 x 2H2O, dihydrate (standard commercial/USP form)
Why this tier: Commonly used clinically as a milder-tolerated alternative to sulfate, but no comparative human bioavailability citation was independently verified.
Source: none located (no human absorption comparison of ferrous gluconate vs sulfate found)