Supplement Scholar
Mineral

Ferrous Sulfate

Buy on Amazon ↗

Affiliate link: we may earn a commission at no extra cost to you. Disclosures

Ferrous Sulfate. Standard low-cost iron salt — effective but commonly causes GI side effects.

How it works. Dissociates in stomach acid; absorbed via DMT1 in duodenum.

What the research supports. 1 graded claims. Strongest: Reliably treats iron-deficiency anemia (strong).

How much to take. Typical dose: 65 mg elemental every other day.

Side effects and interactions. 1 medication interaction listed. Serious: Overdose.

Stacking. Pairs well with A high-quality multivitamin, Omega-3 (EPA/DHA).

Common forms. Available as Chelated form (glycinate, bisglycinate, citrate, malate), Inorganic salt (oxide, sulfate, chloride), Liquid ionic solution, Topical or transdermal preparation.

Key studies. 8 studies cited. The strongest are listed with links to PubMed.

Community. Experiences from people who have tried Ferrous Sulfate. Anecdotes are not medical advice.

Ferrous Sulfate. Standard low-cost iron salt — effective but commonly causes GI side effects.

Molecular structureFeO4S · 151.91 g/mol

What it is

Standard low-cost iron salt — effective but commonly causes GI side effects.

Food sources

Whole foods (leafy greens, legumes, nuts, seeds, seafood, animal proteins)Fortified foods such as cereals, breads, plant milks, and table saltMineral supplements as chelates, citrates, glycinates, or inorganic salts

Goals

Energy ProductionWomen's Health

How it works

Dissociates in stomach acid; absorbed via DMT1 in duodenum.

Pathways

  • Dissociates in stomach acid
  • absorbed via DMT1 in duodenum

Effects

  • +Reliably treats iron-deficiency anemia supports

What the research supports

Reliably treats iron-deficiency anemiastrong

Strong: consistent results across large trials or meta-analyses. Moderate: several trials, mostly positive. Limited: small or mixed studies. Preclinical: animal or cell research only.

Typical dose
65 mg elemental every other day
TimingConsistent daily timing recommended; split larger doses if GI tolerance is a concern.
With foodEmpty stomach with vitamin C
Best formMost evidence is based on the chelated form (glycinate, bisglycinate, citrate, malate) form.
Shop Ferrous Sulfate on Amazon ↗

As an Amazon Associate I earn from qualifying purchases. Look for USP, NSF or Informed Sport seals before you buy.

Side effects & interactions

Common side effects

  • Nausea
  • Constipation
  • Dark stools

Serious

  • Overdose

Medication interactions

Prescription medications (general)minor

Always disclose Ferrous Sulfate use to your prescriber — additive, antagonistic, or pharmacokinetic interactions are possible.

Check any supplement–medication combination with your pharmacist before starting.

Combines with

Pairs well

  • A high-quality multivitaminCovers micronutrient cofactors that support most supplement pathways.
  • Omega-3 (EPA/DHA)Foundational anti-inflammatory support that complements most regimens.

Common forms

  • Chelated form (glycinate, bisglycinate, citrate, malate)
  • Inorganic salt (oxide, sulfate, chloride)
  • Liquid ionic solution
  • Topical or transdermal preparation

Key studies

8 studies cited in total.

PubMed: Ferrous Sulfate — Reliably treats iron-deficiency anemia ↗
Systematic review · PubMed (NLM) · 2026

Opens current human and preclinical literature matching Ferrous Sulfate and "Reliably treats iron-deficiency anemia". Filter by RCT, meta-analysis, or year on the results page.

PubMed: Ferrous Sulfate — randomized controlled trial ↗
Systematic review · PubMed (NLM) · 2026

Opens current human and preclinical literature matching Ferrous Sulfate and "randomized controlled trial". Filter by RCT, meta-analysis, or year on the results page.

PubMed: Ferrous Sulfate — meta-analysis ↗
Systematic review · PubMed (NLM) · 2026

Opens current human and preclinical literature matching Ferrous Sulfate and "meta-analysis". Filter by RCT, meta-analysis, or year on the results page.

Discussion

Loading discussion…