What is the amount of elemental iron in ferrous bisglycinate?

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Last updated: April 23, 2025View editorial policy

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From the Guidelines

Ferrous bisglycinate contains approximately 25 mg of elemental iron per tablet. This information is crucial when taking iron supplements, as dosage recommendations are typically based on the amount of elemental iron needed. According to the study published in Clinical Gastroenterology and Hepatology 1, the approximate elemental iron content in ferrous bisglycinate is 25 mg per tablet. It's essential to understand that ferrous bisglycinate is a chelated form of iron, where the iron is bound to two glycine molecules, creating a structure that helps protect the iron from binding with other substances in the digestive tract.

When considering iron supplements, it's also important to note that the ferrous iron salts (ferrous sulfate, ferrous fumarate, and ferrous gluconate) are often the least expensive options, but some patients may tolerate other products like ferrous bisglycinate better 1. However, the key factor is the amount of elemental iron per dose, as this is the active component that addresses iron deficiency.

Some key points to consider when taking ferrous bisglycinate supplements include:

  • Always check the label to confirm the amount of elemental iron per dose
  • Take iron supplements on an empty stomach with 80 mg ascorbic acid to improve absorption, if possible
  • Avoid consuming tea and coffee within an hour after taking iron, as they can inhibit iron absorption
  • Consider taking iron every other day to improve tolerance, although more research is needed to confirm this approach 1.

From the Research

Elemental Iron Content in Ferrous Bisglycinate

  • The elemental iron content in ferrous bisglycinate is not explicitly stated in the provided studies, but it can be inferred from the dosages and comparisons made between ferrous bisglycinate and other iron supplements.
  • In the study by 2, ferrous glycinate chelate (250 mg/d) was found to correspond to 50 mg of elemental iron, suggesting that the elemental iron content in ferrous bisglycinate may be around 20% of the total compound.
  • However, without direct information on the elemental iron content in ferrous bisglycinate, it is difficult to provide a precise answer.

Comparison of Ferrous Bisglycinate with Other Iron Supplements

  • Studies have compared the efficacy and tolerability of ferrous bisglycinate with other iron supplements, such as ferrous sulfate and ferrous glycine sulfate 3, 4, 5.
  • These studies suggest that ferrous bisglycinate may have similar or better efficacy and lower gastrointestinal toxicity compared to other iron supplements.
  • However, the elemental iron content in ferrous bisglycinate is not directly compared to other iron supplements in these studies.

Dosage and Elemental Iron Content

  • The dosage of ferrous bisglycinate used in the studies varied, ranging from 28 mg per day to 250 mg per day 4, 2.
  • The elemental iron content in these dosages is not explicitly stated, but it can be estimated based on the comparisons made with other iron supplements.
  • For example, the study by 2 used a dosage of 250 mg per day of ferrous glycinate chelate, which corresponded to 50 mg of elemental iron.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Efficacy of ferrous bis-glycinate versus ferrous glycine sulfate in the treatment of iron deficiency anemia with pregnancy: a randomized double-blind clinical trial.

The journal of maternal-fetal & neonatal medicine : the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians, 2019

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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