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Iron Supplement (Oral) Pregnancy: Use of any drug during the first trimester should be avoided if possible, so administration of iron during the first trimester requires definite evidence of iron deficiency; prophylaxis of iron deficiency during the remainder of pregnancy is justified (UK SPC §4.6).

Ferrous Sulphate

Brand names: Ferrograd (200mg), Ironorm Drops, Sytron (ferrous fumarate liquid)

Ferrous sulphate is an oral iron salt used to treat iron-deficiency anaemia.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Iron-deficiency anaemia, therapeutic: one 200 mg coated tablet 2-3 times daily. Prophylaxis: one 200 mg tablet daily
Route: Oral — swallow whole with water; tablets should not be sucked, chewed or kept in the mouth. Take before meals or during meals, depending on gastrointestinal tolerance
Frequency: Two to three times daily (treatment); once daily (prophylaxis)
Doses above are for Ferrous Sulfate 200 mg Coated Tablets. Elderly: as for adults. Children: this presentation is not recommended. Duration of treatment should generally not exceed 3 months after correction of anaemia (§4.4). Co-existing deficiency of vitamin B12 or folic acid should be ruled out, since combined deficiency produces a microcytic blood film. Patients post-gastrectomy have poor absorption of iron. Because of the risk of mouth ulceration and tooth discolouration, tablets must not be sucked, chewed or kept in the mouth. These tablets contain sugar — administer with care to patients with diabetes; patients with rare hereditary problems of fructose intolerance, glucose-galactose malabsorption or sucrase-isomaltase insufficiency should not take this medicine. Label warning: contains iron — keep out of the sight and reach of children, as overdose may be fatal. The SPC states no maximum daily dose beyond the regimen above.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

  • Hypersensitivity to the active substance or to any of the excipients
  • Haemosiderosis and haemochromatosis
  • Active peptic ulcer
  • Repeated blood transfusion
  • Haemolytic anaemia
  • Oral and parenteral iron preparations should not be used concomitantly

Side effects

  • Abdominal pain, nausea and vomiting (usually dose related)
  • Constipation and diarrhoea
  • Dark stools
  • Contact irritation resulting in erosion or ulceration, particularly if tablets become lodged in the upper gastrointestinal tract
  • Mouth ulceration (post-marketing, in the context of incorrect administration — chewing, sucking or keeping tablets in the mouth); elderly patients and those with deglutition disorders may also be at risk of oesophageal lesions or bronchial necrosis in case of false route
  • Allergic reactions

Interactions

  • Antacids and mineral supplements — compounds containing calcium, magnesium, bicarbonates, carbonates, oxalates or phosphates may impair iron absorption; separate administration by at least 2 hours
  • Tetracyclines — iron and tetracyclines reduce each other's absorption; separate by 2 to 3 hours
  • Quinolones — iron may reduce absorption; separate by at least 2 hours
  • Chloramphenicol — delays plasma clearance of iron and its incorporation into red blood cells by interfering with erythropoiesis
  • Bisphosphonates — absorption reduced when taken concurrently; separate by at least 2 hours
  • Cholestyramine — impairs iron absorption
  • Dimercaprol — concomitant administration with oral iron should be avoided
  • Dopaminergics — oral iron may reduce absorption of co-careldopa, entacapone and levodopa
  • Methyldopa — oral iron may antagonise the antihypertensive effect
  • Food — absorption of iron is impaired by tea, eggs or milk

Clinical monograph

How it works

It provides elemental iron for haemoglobin synthesis, correcting iron-deficiency anaemia.

Prescribing in practice

  • Gastrointestinal effects (nausea, constipation, dark stools) are common and dose-related; a lower dose or alternate-day dosing can improve tolerance and may improve absorption.
  • Absorption is reduced by tea, calcium, antacids and some other drugs — separate their timing.
  • Continue treatment for a period after the haemoglobin normalises to replenish iron stores, and investigate the underlying cause.

Monitoring

Monitor haemoglobin and iron stores (ferritin) to confirm response; investigate the cause of the deficiency.

Counselling the patient

  • Stools may turn black, which is harmless.
  • Taking it with a source of vitamin C (e.g. orange juice) aids absorption; avoid taking it with tea or coffee.
  • Keep iron away from children — overdose is dangerous.

Evidence & guidelines

Oral iron is first-line for iron-deficiency anaemia; lower-dose or alternate-day regimens are increasingly preferred for tolerability and absorption.

Reference: NICE NG24 (Anaemia in CKD); BSH Guidelines on Iron Deficiency Anaemia; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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