Overview
Chelated ferrous iron — best-tolerated form with high absorption and minimal GI distress.
Forms & variants of Iron
Different chemical forms of Iron behave differently. Browse each form's mechanism, bioavailability, and best-use context.
Oxygen-carrying mineral central to hemoglobin and cellular respiration.
Standard low-cost iron salt — effective but commonly causes GI side effects.
Animal-source heme iron — absorbed via separate receptor, unaffected by phytates/calcium.
Mechanism of action
Amino acid chelate absorbed via dipeptide transporters, bypassing competition with calcium/phytate.
Effects on the body
Organ system effects
Evidence-based benefits
Equivalent ferritin rise to ferrous sulfate with fewer side effects
Moderate evidencePotential side effects
- · Dark stools
- · Constipation
- · Pediatric overdose lethal — keep secure
Drug interactions
Supplement interactions
- Vitamin CReduces ferric→ferrous for better absorption.
No specific avoidances listed.
Dosing & bioavailability
Where to buy
Affiliate-style search links to reputable retailers. We don't endorse specific brands — verify third-party testing (USP, NSF, Informed Sport) before purchase.
Scientific evidence (8)
Iron bisglycinate vs ferrous sulfate in iron-deficiency anemia
Milman N, et al.
RCT in pregnant women.
Comparable hemoglobin response with fewer GI side effects.
PubMed: Iron Bisglycinate — Equivalent ferritin rise to ferrous sulfate with fewer side effects
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PubMed: Iron Bisglycinate — randomized controlled trial
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PubMed: Iron Bisglycinate — meta-analysis
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PubMed: Iron Bisglycinate — pharmacokinetics
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PubMed: Iron Bisglycinate — safety adverse events
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PubMed: Iron Bisglycinate — dose response
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Google Scholar: Iron Bisglycinate — clinical evidence
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