VitaminWell-studiedMineral

Iron Bisglycinate

Also known as Iron

Half-life

~6 hours

What is Iron Bisglycinate?

Chelated iron form with superior absorption and dramatically fewer GI side effects than ferrous sulfate.

How Iron Bisglycinate works

Glycine amino acid chelation protects iron from forming insoluble precipitates in the GI tract, enabling intestinal uptake via peptide transporters (PepT1), resulting in 60–90% better absorption than ferrous sulfate with less oxidative GI damage.

Benefits & uses

Corrects iron-deficiency anemia
Energy/reduces fatigue
Oxygen transport

Common uses: Iron deficiency anemia, fatigue, athletic performance (oxygen transport), hair loss.

Iron Bisglycinate dosage

Typical dose: Men: 8 mg/day. Women (premenopausal): 18 mg/day. Deficiency repletion: 25–50 mg/day fasted with vitamin C. Monitor ferritin.

Iron Bisglycinate half-life

~6 hours (plasma iron); storage iron half-life varies by stores

Iron Bisglycinate side effects

Fewer GI side effects than ferrous sulfate. Still can cause constipation if overused.

Mild constipation at higher doses
Dark stools (harmless)
GI cramping if taken on empty stomach at very high doses
Iron overload (hemochromatosis risk) — never supplement without blood work confirming deficiency
Constipation
GI upset
Dark stools

Warnings & monitoring

Only supplement if deficient — iron overload is harmful; keep away from children

Iron Bisglycinate interactions

with Calcium
Caution · mild
Calcium strongly inhibits non-heme iron absorption in the gut. Taking both together can significantly reduce iron bioavailability — particularly important for those treating iron-deficiency anemia.
Timing: Separate calcium and iron supplements by at least 2 hours

Commonly stacked with

Vitamin C (Ascorbic Acid)

Track Iron Bisglycinate in Protokol.

Log doses, model half-lives, check interactions, and line it all up against your bloodwork. Free on iPhone and Android.

Get it on Google Play

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