Organically bound, bivalent iron, surrounded by amino acids. The amino acids act as a protective covering, ensuring that the iron-amino acid complex is not broken down by the stomach acids, but is absorbed in the small intestine. This helps to avoid side effects that may be caused by free iron ions, such as constipation, nausea and stomach disorders. Unlike other forms, iron bisglycinate does not carry an electric charge, is neutral compound, and therefore does not prevent the absorption of other nutrients, such as calcium, vitamin E or vitamin C.

Retard pellets release small amounts of vitamin C in the body, covering its needs for up to 12 hours. Vitamin C protects ferrous iron from oxidation and contributes to better absorption of dietary iron during the day.