Ferrous Fumarate
A standard iron salt with about 33% elemental iron. It treats iron-deficiency anemia as well as ferrous sulfate; in the one head-to-head trial it also caused the most side effects.
Evidence last reviewed: August 2026
What the science says
- As effective as other iron salts Moderate evidence
A randomized trial in 120 pregnant women with iron-deficiency anemia compared ferrous sulfate, fumarate, ascorbate and carbonyl iron at 200 mg elemental iron/day. All four were equally effective on haemoglobin and iron indices and equally cost-effective; adverse effects were most frequent in the fumarate group (56.7%).
- Absorption matches ferrous sulfate Moderate evidence
A stable-isotope study in Mexican women, infants and young children found no significant difference in iron absorption between ferrous fumarate and ferrous sulfate, with relative bioavailability of 86–106% depending on the group.
Dosage & safety
Scientific references
- A randomized controlled trial comparing the efficacy, tolerability, and cost of oral iron preparations in iron-deficiency anemia in pregnancy
- A comparison of the bioavailability of ferrous fumarate and ferrous sulfate in non-anemic Mexican women and children consuming a sweetened maize and milk drink
Where to buy
Ships to 180+ countries · welcome discount for new customers
Referral link — this site may earn a commission on purchases.
Related in Vitamins & minerals
- Vitamin A (Retinol) Moderate evidence
- Vitamin B1 (Thiamine) Moderate evidence
- Vitamin B5 (Pantothenic Acid) Limited evidence
- Vitamin B6 (Pyridoxine) Moderate evidence
- Vitamin K1 Limited evidence
- Calcium Moderate evidence