NutriStack
Doxycycline and Iron, timing-sensitive.
Iron forms chelation complexes with doxycycline that significantly impair antibiotic absorption. Studies show iron can reduce tetracycline absorption by 50-90%. This interaction is clinically significant and can lead to antibiotic treatment failure.
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.
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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 Iron
- Pair type
- Timing Sensitive
- Evidence (highest tier)
- Strong
- Source citations
- 5 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. Iron forms chelation complexes with doxycycline that significantly impair antibiotic absorption. Studies show iron can reduce tetracycline absorption by 50-90%. This interaction is clinically significant and can lead to antibiotic treatment failure.
Mechanism. Iron (Fe2+ and Fe3+) chelates doxycycline through its hydroxyl and keto groups, forming insoluble iron-tetracycline complexes. Iron is a particularly strong chelator of tetracyclines, producing very stable complexes with minimal dissociation.
Recommendation. Separate doxycycline and iron supplements by at least 2 hours. Take doxycycline at least 2 hours before or after iron to ensure adequate antibiotic absorption and treatment efficacy.
Minimum separation. 120
Sources (5)
- Neuvonen PJ. Interactions with the absorption of tetracyclines. Drugs. 1976;11(1):45-54. PMID 1083209
- Fischer JAJ, Cherian AM, Bone JN, Karakochuk CD. The effects of oral ferrous bisglycinate supplementation on hemoglobin and ferritin concentrations in adults and children: a systematic review and meta-analysis of randomized controlled trials. Nutrition Reviews. 2023. PMID 36728680
- Rehman T, Agrawal R, Ahamed F et al.. Optimal dose and duration of iron supplementation for treating iron deficiency anaemia in children and adolescents: A systematic review and meta-analysis. PLoS One. 2025. PMID 39951396
- Gutema BT, Sorrie MB, Megersa ND et al.. Effects of iron supplementation on cognitive development in school-age children: Systematic review and meta-analysis. PLoS One. 2023. PMID 37368919
- Hansen R, Sejer EPF, Holm C, Schroll JB. Iron supplements in pregnant women with normal iron status: A systematic review and meta-analysis. Acta Obstetricia et Gynecologica Scandinavica. 2023. PMID 37403900
Stack Score
How this pair moves the number.
Effect on the composite score
If both Doxycycline and Iron 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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