Quick answer
Iron bisglycinate is iron bound to two glycine molecules (a chelated form). Ferrous sulfate is an iron salt and one of the most common, inexpensive forms. They differ in chemical form, elemental iron per milligram and how they're described on labels, so always compare the elemental iron per serve.
Common forms of iron in supplements
| Iron form | Type | Approx. elemental iron by weight* |
|---|---|---|
| Ferrous sulfate | Iron salt | About 20% |
| Ferrous fumarate | Iron salt | About 33% |
| Ferrous gluconate | Iron salt | About 12% |
| Iron bisglycinate | Chelate (bound to glycine) | About 20% |
*Approximate figures commonly cited for the dry compounds. Labels usually state the elemental iron per serve, which is the number to compare.
What is iron bisglycinate?
Iron bisglycinate (also called ferrous bisglycinate) is iron held by two molecules of the amino acid glycine. It's often chosen by people looking for a gentle, well-defined form of iron. See Chelated Minerals Explained.
What is ferrous sulfate?
Ferrous sulfate is a simple iron salt. It's widely available and inexpensive, and has been used for a very long time.
Iron in the Australian diet
- Haem iron comes from animal foods such as red meat, poultry and fish.
- Non-haem iron comes from plant foods such as legumes, tofu, leafy greens and iron-fortified cereals.
- Vitamin C-rich foods are often eaten alongside plant sources of iron.
Tip: Only take iron supplements if you need them. Too much iron can be harmful, so check with your doctor first.
Frequently asked questions
Is iron bisglycinate the same as ferrous bisglycinate?
Yes. Both names describe iron bound to two glycine molecules.
Which form of iron has the most iron?
Per gram of compound, ferrous fumarate contains the most elemental iron of the common forms. What matters on a label is the elemental iron per serve.
Can I take iron with coffee or tea?
Follow your product's label and your healthcare professional's advice about timing iron with food and drinks.
Keep reading
This article is general information only and is not medical advice. Always read the label and follow the directions for use. Dietary supplements should not replace a balanced diet. If you are pregnant, breastfeeding, taking medication or have a medical condition, speak with your doctor or pharmacist before taking a new supplement.
