ModerateTetracyclines×Mineral supplements. Macrominerals
Updated · Methodology
Mechanism
Magnesium shares the list with calcium and iron in the doxycycline label. Beyond the supplement, the warning covers magnesium antacids, which patients tend to take precisely for the stomach upset the antibiotic causes.
Symptoms
Reduced course efficacy with no warning signs. The loop closes on itself: the antibiotic causes heartburn, the antacid lowers the antibiotic.
Management
Space by 2–3 hours. For doxycycline's stomach upset, taking it with food and plenty of water works better than adding a magnesium or aluminium antacid.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.
Summary of a multi-drug list →
Medicine list: everything you take in one place →
Sources
- AEMPS: Ficha técnica Doxiciclina Normon 100 mg comprimidos recubiertos (2024)– AEMPS, CIMA, nº registro 47077, sección 4.5
- NIH Office of Dietary Supplements: Magnesium – Health Professional Fact Sheet (2025)– NIH ODS, Magnesium, Interactions with Medications