What is the dosing for ferrous sulfate (Iron Supplement)?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: April 23, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

Ferrous sulfate should be dosed at 200 mg (65 mg elemental iron) orally once daily for adults with iron deficiency anemia, as this is a reasonable compromise option for initial treatment 1. The optimal dosage and timing of oral iron replacement therapy (IRT) for adults with iron deficiency anemia (IDA) are not clearly defined, but a once daily dose of 50–100 mg of elemental iron may be the best option 1. Key considerations for ferrous sulfate dosing include:

  • Taking the medication on an empty stomach, 1 hour before or 2 hours after meals, to enhance absorption
  • Avoiding concurrent intake of calcium, antacids, dairy, tea, coffee, or whole-grain foods, as these decrease absorption
  • Considering administration with vitamin C (like orange juice) to enhance absorption
  • Monitoring for common side effects, such as constipation, black stools, and stomach upset, and adjusting the dosing regimen as needed
  • Continuing treatment for 3-6 months to replenish iron stores even after hemoglobin normalizes, although the optimal duration is unclear 1. It is essential to monitor the initial haematological response to ferrous sulfate and modify the treatment regimen as appropriate in cases of apparent therapeutic failure 1. In patients with significant intolerance to oral IRT, alternative options such as oral ferric maltol, alternate day oral iron, or parenteral iron may be considered 1. Regular hemoglobin monitoring is recommended to ensure an ultimately satisfactory response, with an optimal interval of every 4 weeks until the hemoglobin is in the normal range 1.

From the FDA Drug Label

CONTAINS: Each tablet contains 324 mg of ferrous sulfate, equivalent to 65 mg of elemental iron, providing 362% of the U.S. recommended daily intake (RDI) of iron for adults and children 4 and older.

16 HOW SUPPLIED Ferrous Sulfate Tablets are available as follows: Each tablet contains 324mg of ferrous sulfate, equivalent to 65mg of elemental iron, providing 362% of the U.S. recommended daily intake (RDI) of iron for adults and children 4 and older.

The dosage of ferrous sulfate is not explicitly stated in the provided drug labels. The labels only provide information on the composition of each tablet, which contains 324 mg of ferrous sulfate, equivalent to 65 mg of elemental iron 2 2.

From the Research

Ferrous Sulfate Dosing

There are no research papers to assist in answering this question about ferrous sulfate dosing, as the provided study 3 discusses the total condylar knee prosthesis and its application in knee deformities, with no mention of ferrous sulfate or its dosing.

  • The study 3 focuses on the outcomes of 220 arthroplasties in 183 patients, using the total condylar knee prosthesis.
  • It reports on the assessment of patients using The Hospital for Special Surgery scoring system, with 62% of knees rated as excellent and 28% as good.
  • Complications and reoperation rates are also discussed in the study 3, but there is no relevant information on ferrous sulfate dosing.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

The total condylar knee prosthesis. A report of two hundred and twenty cases.

The Journal of bone and joint surgery. American volume, 1979

Related Questions

What is the significance of a 40-year-old female's iron level of 73 mcg/dL, Total Iron-Binding Capacity (TIBC) of 346 mcg/dL, and iron saturation of 21%, which are indicative of hypoferritinemia and decreased iron saturation?
What is the diagnosis for a 43-year-old female with hypoferritinemia (Iron: 37 mcg/dL), elevated Total Iron-Binding Capacity (TIBC: 417 mcg/dL), and low Iron Saturation (11%)?
What is the significance of low iron saturation in a 44-year-old female with hypertension (HTN) and type 2 diabetes mellitus (DM), with lab results showing hypoferritinemia (iron 58 mcg/dL), elevated total iron-binding capacity (TIBC) (395 mcg/dL), and low iron saturation (15%)?
What is the diagnosis for a patient with mild normocytic anemia, slight non-specific poikilocytosis, inappropriately low reticulocytes (reticulocyte count), mild absolute monocytosis (mononuclear cell increase), and slight cytoplasmic toxic granulations in neutrophils?
What is the significance of low iron saturation and ferritin levels in a 32-year-old female taking 325mg of iron (ferrous sulfate) daily, with laboratory results showing hypoferritinemia and elevated Total Iron-Binding Capacity (TIBC)?
What labs to order for Congenital Adrenal Hyperplasia (CAH) diagnosis?
Why do lung cancer patients develop pleural (fluid in the pleural space) effusion?
What is the diagnosis and treatment for arthritis of the facet joint of the lumbar spine?
What is the cause of persistent mild left-sided hydronephrosis (kidney swelling due to urine accumulation) with normal bladder function and prostate size, and incidental mild hepatic steatosis (fatty liver disease)?
What bacteria are susceptible to Doxycycline (tetracycline antibiotic)?
What are the findings of the FLAURA (FLAURA) and FLAURA 2 research articles regarding Non-Small Cell Lung Cancer (NSCLC) treatment?

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.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.