What kind of interaction is it?

Timing-sensitive: the two substances can be taken on the same day but should be separated by a minimum time window.

Is this interaction backed by published research?

Yes. NutriStack lists 5 citation rows for the Alendronate + Iron pair, each linking to PubMed by PMID where available. Full sourcing methodology at https://nutristackapp.com/methodology/interactions.

Interaction databaseSupplement × PrescriptionReviewed May 2026

Alendronate and Iron, timing-sensitive.

Q: Can I take Alendronate and Iron together?

Yes, if you separate them in time. Alendronate and Iron have a documented timing-sensitive interaction. Iron chelates alendronate in the GI tract, substantially reducing the already-poor oral absorption of this bisphosphonate. Given alendronate's baseline bioavailability is less than 1%, any chelation interaction is clinically critical.

Q: How does this affect a NutriStack Stack Score?

-5 to your Stack Score per scored timing-sensitive row.

Iron chelates alendronate in the GI tract, substantially reducing the already-poor oral absorption of this bisphosphonate. Given alendronate's baseline bioavailability is less than 1%, any chelation interaction is clinically critical.

5 primary source citations. Moderate evidence. Last verified May 30, 2026.

Open the interaction checker →Read the methodology

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.

Sourcing standards·Evidence tiers

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 Iron
Pair type: Timing Sensitive
Evidence (highest tier): Moderate
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 · Moderate evidence

Timing Sensitive

What is happening. Iron chelates alendronate in the GI tract, substantially reducing the already-poor oral absorption of this bisphosphonate. Given alendronate's baseline bioavailability is less than 1%, any chelation interaction is clinically critical.

Mechanism. Iron cations form stable chelate complexes with alendronate's phosphonate groups, creating insoluble iron-bisphosphonate precipitates that cannot be absorbed. This further reduces the drug's already minimal bioavailability.

Recommendation. Take alendronate at least 30 minutes before iron supplements. Follow standard alendronate dosing: take with plain water first thing in the morning, remain upright, and avoid all food and supplements for at least 30 minutes.

Minimum separation. 30

Sources (5)

Stack Score

How this pair moves the number.

Effect on the composite score

If both Alendronate 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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