NutriStack
Alendronate and Zinc, timing-sensitive.
Zinc is a divalent cation that chelates alendronate in the gut, similar to the well-known calcium, iron, and magnesium interactions. Because alendronate's oral bioavailability is already less than 1%, any further chelation can meaningfully cut the absorbed dose.
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
- Alendronate and Zinc
- Pair type
- Timing Sensitive
- Evidence (highest tier)
- Moderate
- 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 · Moderate evidence
Timing Sensitive
What is happening. Zinc is a divalent cation that chelates alendronate in the gut, similar to the well-known calcium, iron, and magnesium interactions. Because alendronate's oral bioavailability is already less than 1%, any further chelation can meaningfully cut the absorbed dose.
Mechanism. Zn2+ binds to the phosphonate groups of alendronate forming a poorly soluble complex that cannot be absorbed in the proximal small intestine.
Recommendation. Take alendronate alone with plain water on an empty stomach, stay upright for 30 minutes, and only then have breakfast or any zinc-containing supplement or multivitamin.
Minimum separation. 30
Sources (2)
- Wiesner A, Szuta M, Galanty A, Paśko P. Optimal Dosing Regimen of Osteoporosis Drugs in Relation to Food Intake as the Key for the Enhancement of the Treatment Effectiveness-A Concise Literature Review. Foods. 2021;10(4):720. PMID 33805435
- Kim JS, Jang SW, Son M, Kim BM, Kang MJ. Enteric-coated tablet of risedronate sodium in combination with phytic acid, a natural chelating agent, for improved oral bioavailability. Eur J Pharm Sci. 2016;82:36-42. PMID 26594027
Stack Score
How this pair moves the number.
Effect on the composite score
If both Alendronate and Zinc 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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