Ferrous Sulfate vs. Ferrous Gluconate
Among 1,931 on-market iron products with an identifiable primary form, 8.2% use Ferrous Sulfate (159 products) and 7.1% use Ferrous Gluconate (138).
| Ferrous Sulfate | Ferrous Gluconate | |
|---|---|---|
| Quality tier | Tier 2 | Unrated |
| Iron by weight | 20.1% | 11.6% |
| Share of market | 8.2% | 7.1% |
| On-market products | 159 | 138 |
| Median declared dose | 18 elemental mg middle half: 11.5–65 | 9 elemental mg middle half: 3–17.25 |
| Most common brands | Geri-Care, Rugby, Major | 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 Sulfate is tier 2
Reference-standard iron salt used as the comparator in most bioavailability literature; showed lower apparent bioavailability (26.7%) than bisglycinate chelate (90.9%) in one head-to-head pediatric trial.
Source: Pineda O, Ashmead HD. 2001, PMID 11377130
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
Other iron comparisons
- Ferrous Fumarate vs. Ferrous/Iron Bisglycinate Chelate
- Ferrous Fumarate vs. Iron Amino Acid Chelate
- Ferrous Fumarate vs. Ferrous Sulfate
- Ferrous Fumarate vs. Ferrous Gluconate
- 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