Ferrous Fumarate vs. Ferrous Gluconate
Among 1,931 on-market iron products with an identifiable primary form, 60.8% use Ferrous Fumarate (1,174 products) and 7.1% use Ferrous Gluconate (138).
| Ferrous Fumarate | Ferrous Gluconate | |
|---|---|---|
| Quality tier | Unrated | Unrated |
| Iron by weight | 32.9% | 11.6% |
| Share of market | 60.8% | 7.1% |
| On-market products | 1,174 | 138 |
| Median declared dose | 18 elemental mg middle half: 8–26 | 9 elemental mg middle half: 3–17.25 |
| Most common brands | DC, Wonder Laboratories, GNC Women's Ultra Mega | Wonder Laboratories, DC, ALLMAX |
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 Ferrous Gluconate is unrated
Commonly used clinically as a milder-tolerated alternative to sulfate, but no comparative human bioavailability citation was independently verified.
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 iron comparisons
- Ferrous Fumarate vs. Ferrous/Iron Bisglycinate Chelate
- Ferrous Fumarate vs. Iron Amino Acid Chelate
- Ferrous Fumarate vs. Ferrous Sulfate
- Ferrous/Iron Bisglycinate Chelate vs. Iron Amino Acid Chelate
- Ferrous/Iron Bisglycinate Chelate vs. Ferrous Sulfate
- Ferrous/Iron Bisglycinate Chelate vs. Ferrous Gluconate
- Iron Amino Acid Chelate vs. Ferrous Sulfate
- Iron Amino Acid Chelate vs. Ferrous Gluconate
- Ferrous Sulfate vs. Ferrous Gluconate