Severe interactionSevereSeparate by 3h

Magnesium oxide and Tetracycline antibiotic: interaction, severity and spacing

Magnesium oxide and Tetracycline antibiotic interact because divalent cations chelate tetracyclines in the gut to form non-absorbable complexes, which can cut antibiotic absorption by more than half. Take them 3 hours apart. Severe risk.

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

The interaction in detail

Summary of the Magnesium oxide and Tetracycline antibiotic interaction
PairMagnesium oxide and Tetracycline antibiotic
TypeNutrient–drug interaction
SeveritySevere
Required spacing3 hours minimum
OnsetAt the time of dosing

Mechanism

Divalent cations chelate tetracyclines in the gut to form non-absorbable complexes, which can cut antibiotic absorption by more than half.

What to do

Separate magnesium and tetracyclines by at least 2 hours before or 4-6 hours after the antibiotic dose.

Magnesium oxide and Tetracycline antibiotic: common questions