Moderate interactionModerateSeparate by 1h

Iron bisglycinate and Black tea: interaction, severity and spacing

Iron bisglycinate and Black tea interact because tannins in black tea form insoluble complexes with non-heme iron, cutting absorption by up to 60-70% at the same meal. Take them 1 hours apart. Moderate risk.

Last reviewed: 2026-09-20Reviewed by: StackingRight clinical review

The interaction in detail

Summary of the Iron bisglycinate and Black tea interaction
PairIron bisglycinate and Black tea
TypeFood interaction
SeverityModerate
Required spacing1 hours minimum
OnsetAt the time of dosing

Mechanism

Tannins in black tea form insoluble complexes with non-heme iron, cutting absorption by up to 60-70% at the same meal.

What to do

Leave at least 1 hour between iron and tea. Drink tea between meals rather than with them.

How to fit both into one day

Iron bisglycinate
morningempty stomach

Non-heme iron absorbs best on an empty stomach with vitamin C. Coffee, tea and calcium can halve absorption, so keep them two hours away.

Putting Iron bisglycinate in the morning and Black tea in the evening satisfies the 1-hour separation without disrupting either one's absorption window.

Iron bisglycinate and Black tea: common questions