Feosol Original , a high potency iron, contains ferrous sulfate. When your doctor suggests an iron supplement for low iron, ferrous sulfate is a time-tested form of iron. Each Feosol Original tablet contains 65 mg of elemental iron, equivalent to 325 mg of ferrous sulfate, which provides 360% of Daily Value, making it a high potency iron supplement. Use as directed; keep out of reach of children. A trusted brand for seven decades: Feosol has been a leader and innovator of iron supplements for seventy years. Feosol, the #1 Pharmacist Recommended iron supplement brand.*