How to Take Ferrous Sulfate
Ferrous sulfate should be taken once daily (providing 65mg of elemental iron), preferably in the morning on an empty stomach to maximize absorption. 1
Dosing Recommendations
- Standard dose: One tablet (324mg ferrous sulfate = 65mg elemental iron) once daily 2, 1, 3
- Timing: Take in the morning on an empty stomach (1 hour before or 2 hours after meals) 1
- Duration: Continue for 3 months after hemoglobin normalization to adequately replenish iron stores 1
Optimizing Absorption
- Take with vitamin C: Consider taking with a glass of orange juice or vitamin C supplement to enhance absorption 1
- Avoid interference: Do not take with:
- Calcium-containing foods/supplements (dairy products)
- Tea or coffee
- Antacids
- Proton pump inhibitors
- These should be separated by at least 2 hours from iron intake
Alternate Dosing Strategies
For patients experiencing significant gastrointestinal side effects:
- Alternate-day dosing: Taking iron every other day may improve absorption and reduce side effects 4
- After-meal dosing: If stomach upset occurs, taking with food may help, though absorption will be reduced
Monitoring Response
- Expect hemoglobin to rise by approximately 2 g/dL after 3-4 weeks of therapy 1
- An absence of hemoglobin rise of at least 10 g/L after 2 weeks strongly predicts treatment failure 2
- Regular monitoring (every 4-6 weeks initially) is recommended to ensure treatment efficacy 1
Managing Side Effects
Common side effects include:
- Constipation
- Nausea
- Abdominal discomfort
- Black stools (harmless but normal)
If side effects are troublesome:
- Consider reducing to every-other-day dosing
- Take with small amounts of food (though this reduces absorption)
- Ensure adequate hydration and dietary fiber
Important Considerations
- Black stools are normal and expected with iron supplementation
- Store tablets away from children as iron overdose can be fatal in children
- Do not take more than the prescribed dose
- Avoid modified-release preparations as they are less effective and more expensive 2
Taking ferrous sulfate correctly is crucial for effectively treating iron deficiency while minimizing side effects. The once-daily morning dosing on an empty stomach represents the optimal balance between efficacy and tolerability for most patients.