Overview
Chelated ferrous iron — best-tolerated form with high absorption and minimal GI distress.
- Whole foods (leafy greens, legumes, nuts, seeds, seafood, animal proteins)
- Fortified foods such as cereals, breads, plant milks, and table salt
- Mineral supplements as chelates, citrates, glycinates, or inorganic salts
- Chelated form (glycinate, bisglycinate, citrate, malate)
- Inorganic salt (oxide, sulfate, chloride)
- Liquid ionic solution
- Topical or transdermal preparation
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.
- · Amino acid chelate absorbed via dipeptide transporters, bypassing competition with calcium/phytate
Effects on the body
Organ system effects
Iron Bisglycinate supports mitochondrial ATP production and fatigue resistance.
Iron Bisglycinate has documented effects on female reproductive endocrinology and cycle regulation.
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 links — we may earn a commission at no extra cost to you. Amazon code supplementsch-20 is auto-applied at checkout. We don't endorse specific brands; verify third-party testing (USP, NSF, Informed Sport) before purchase.
Third-party testedIndependently verified Iron Bisglycinate — look for USP, NSF, or Informed Sport seals on the label for purity and dose accuracy.Iron Bisglycinate third party tested NSF
CapsulesPre-measured Iron Bisglycinate capsules — easiest for travel and consistent daily dosing without scoops or scales.Iron Bisglycinate capsules
PowderBulk unflavored Iron Bisglycinate powder — best cost-per-gram and flexible dosing for stacking or mixing into drinks.Iron Bisglycinate powder unflavored
Best sellersMost-purchased Iron Bisglycinate products on Amazon — a quick way to see what's reviewed widely before you commit.Iron Bisglycinate best sellerScientific evidence8Show studiesHide studies
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
Live PubMed search
Live results for "Iron Bisglycinate Equivalent ferritin rise to ferrous sulfate with fewer side effects" across the PubMed/MEDLINE peer-reviewed index.
Opens current human and preclinical literature matching Iron Bisglycinate and "Equivalent ferritin rise to ferrous sulfate with fewer side effects". Filter by RCT, meta-analysis, or year on the results page.
PubMed: Iron Bisglycinate — randomized controlled trial
Live PubMed search
Live results for "Iron Bisglycinate randomized controlled trial" across the PubMed/MEDLINE peer-reviewed index.
Opens current human and preclinical literature matching Iron Bisglycinate and "randomized controlled trial". Filter by RCT, meta-analysis, or year on the results page.
PubMed: Iron Bisglycinate — meta-analysis
Live PubMed search
Live results for "Iron Bisglycinate meta-analysis" across the PubMed/MEDLINE peer-reviewed index.
Opens current human and preclinical literature matching Iron Bisglycinate and "meta-analysis". Filter by RCT, meta-analysis, or year on the results page.
PubMed: Iron Bisglycinate — pharmacokinetics
Live PubMed search
Live results for "Iron Bisglycinate pharmacokinetics" across the PubMed/MEDLINE peer-reviewed index.
Opens current human and preclinical literature matching Iron Bisglycinate and "pharmacokinetics". Filter by RCT, meta-analysis, or year on the results page.
PubMed: Iron Bisglycinate — safety adverse events
Live PubMed search
Live results for "Iron Bisglycinate safety adverse events" across the PubMed/MEDLINE peer-reviewed index.
Opens current human and preclinical literature matching Iron Bisglycinate and "safety adverse events". Filter by RCT, meta-analysis, or year on the results page.
PubMed: Iron Bisglycinate — dose response
Live PubMed search
Live results for "Iron Bisglycinate dose response" across the PubMed/MEDLINE peer-reviewed index.
Opens current human and preclinical literature matching Iron Bisglycinate and "dose response". Filter by RCT, meta-analysis, or year on the results page.
Google Scholar: Iron Bisglycinate — clinical evidence
Live Scholar search
Cross-database citation index for Iron Bisglycinate as it relates to "clinical evidence".
Includes preprints, theses, and journal articles. Useful for tracking citation counts and follow-on work.