NutriStack
Doxycycline and Magnesium Citrate, timing-sensitive.
Magnesium citrate releases Mg2+ that chelates doxycycline in the gut and reduces antibiotic absorption. The interaction applies to all magnesium salts and can cause subtherapeutic doxycycline levels.
One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
Same shape as the other 1,729 pairs in the public database.
From the interaction database
What the row says.
Every entry follows the same shape: what is happening, the mechanism, the recommendation, and the primary literature.
At a glance
- Substances
- Doxycycline and Magnesium Citrate
- Pair type
- Timing Sensitive
- Evidence (highest tier)
- Strong
- Source citations
- 2 sources
- Stack Score effect
- −5 to your Stack Score (per scored timing-sensitive row).
- Scope
- Supplement × Prescription
- Last verified
- May 30, 2026
Timing Sensitive · Strong evidence
Timing Sensitive
What is happening. Magnesium citrate releases Mg2+ that chelates doxycycline in the gut and reduces antibiotic absorption. The interaction applies to all magnesium salts and can cause subtherapeutic doxycycline levels.
Mechanism. Mg2+ from magnesium citrate chelates the beta-diketone system of tetracyclines, forming insoluble complexes that block intestinal absorption.
Recommendation. Take doxycycline at least 2 hours before or 6 hours after magnesium citrate. Do not co-administer.
Minimum separation. 360
Sources (2)
- Gugler R, Allgayer H. Effects of antacids on the clinical pharmacokinetics of drugs. An update. Clin Pharmacokinet. 1990;18(3):210-219. PMID 1969784
- Eljaaly K, Helal A, Almandeel T, Algarni R, Alshehri S. Multivalent cations interactions with fluoroquinolones or tetracyclines: A cross-sectional study. Saudi J Biol Sci. 2021;28(12):6929-6932. PMID 34866992
Stack Score
How this pair moves the number.
Effect on the composite score
If both Doxycycline and Magnesium Citrate are in the same stack, this pair applies −5 to your Stack Score (per scored timing-sensitive row).
The full algorithm, the clamping rules, and four worked stacks are documented at /methodology/stack-score.
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