Supplement Scholar
Mineral

Iron Bisglycinate

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Iron Bisglycinate. Chelated ferrous iron — best-tolerated form with high absorption and minimal GI distress.

How it works. Amino acid chelate absorbed via dipeptide transporters, bypassing competition with calcium/phytate.

What the research supports. 1 graded claims. Strongest: Equivalent ferritin rise to ferrous sulfate with fewer side effects (moderate).

How much to take. Typical dose: 18–25 mg elemental every other day.

Side effects and interactions. 1 medication interaction listed. Serious: Pediatric overdose lethal — keep secure.

Stacking. Pairs well with Vitamin C.

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 Iron Bisglycinate. Anecdotes are not medical advice.

Iron Bisglycinate. Chelated ferrous iron — best-tolerated form with high absorption and minimal GI distress.

Molecular structureC4H10FeN2O4 · 205.98 g/mol

What it is

Chelated ferrous iron — best-tolerated form with high absorption and minimal GI distress.

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 HealthFertility

How it works

Amino acid chelate absorbed via dipeptide transporters, bypassing competition with calcium/phytate.

Pathways

  • Amino acid chelate absorbed via dipeptide transporters, bypassing competition with calcium/phytate

Effects

  • +Equivalent ferritin rise to ferrous sulfate with fewer side effects supports

What the research supports

Equivalent ferritin rise to ferrous sulfate with fewer side effectsmoderate

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
18–25 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.
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Side effects & interactions

Common side effects

  • Dark stools

Serious

  • Pediatric overdose lethal — keep secure

Medication interactions

Thyroid hormone, fluoroquinolones, levodopamoderate

Separate by 2–4 hours.

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

Combines with

Pairs well

  • Vitamin CReduces ferric→ferrous for better absorption.

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: Iron Bisglycinate — Equivalent ferritin rise to ferrous sulfate with fewer side effects ↗
Systematic review · PubMed (NLM) · 2026

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 ↗
Systematic review · PubMed (NLM) · 2026

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 ↗
Systematic review · PubMed (NLM) · 2026

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

Discussion

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