Iron bisglycinate: compound weight against elemental iron

The chelate weighs more than the iron in it

Iron bisglycinate is iron bound to two glycine molecules. The glycine has real weight, so the milligrams of iron bisglycinate and the milligrams of iron are not the same number.

A pack quoting only the chelate weight is quoting the raw material. The iron figure has to be read from the nutrient panel.

Which figure the nutrient panel uses

The panel row headed iron is expressed as elemental iron per stated portion. That is the figure designed for comparison.

The ingredients list names the chelate. Seeing a larger number there than in the panel is expected and is not a discrepancy.

Other iron compounds on other labels

Comparison shopping across iron products means crossing several compounds, each with its own proportion of elemental iron by weight.

• Ferrous sulfate, ferrous fumarate and ferrous gluconate are common salts.
• Iron bisglycinate is a chelate rather than a simple salt.
• Only the elemental iron row is comparable from one of these to another.

The NRV percentage in plain terms

The nutrient reference value for iron is a fixed figure set in law. The percentage states the portion against that reference, which lets you compare two labels without doing any chemistry.

It is a comparison device, not guidance, and it sits beside the elemental figure rather than instead of it.

Sixty capsules and the portion question

This pack is listed as 60 capsules. A smaller count than a 90 capsule pack says nothing until each label's portion is known.

Convert both packs to portions first, then compare cost per portion. Capsule for capsule comparisons mislead whenever the portions differ.

What the label tells you

The full ingredients list, the amount per portion, allergens, dietary suitability, directions and storage are printed on the pack.

Read the label before you take any supplement, and check the product page for the format, pack size and price before you buy.