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 2 citation rows for the Fexofenadine + Green Tea Extract pair, each linking to PubMed by PMID where available. Full sourcing methodology at https://nutristackapp.com/methodology/interactions.

Interaction databaseSupplement × PrescriptionReviewed May 2026

Fexofenadine and Green Tea Extract, timing-sensitive.

Q: Can I take Fexofenadine and Green Tea Extract together?

Yes, if you separate them in time. Fexofenadine and Green Tea Extract have a documented timing-sensitive interaction. Green tea extract can sharply reduce fexofenadine absorption when taken together. In a randomized crossover study, an EGCG-rich green tea extract reduced fexofenadine AUC and peak concentration by about 70%. This may make fexofenadine less effective for allergic rhinitis or hives.

Q: How does this affect a NutriStack Stack Score?

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

Green tea extract can sharply reduce fexofenadine absorption when taken together. In a randomized crossover study, an EGCG-rich green tea extract reduced fexofenadine AUC and peak concentration by about 70%. This may make fexofenadine less effective for allergic rhinitis or hives.

2 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: Fexofenadine and Green Tea Extract
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. Green tea extract can sharply reduce fexofenadine absorption when taken together. In a randomized crossover study, an EGCG-rich green tea extract reduced fexofenadine AUC and peak concentration by about 70%. This may make fexofenadine less effective for allergic rhinitis or hives.

Mechanism. Fexofenadine requires intestinal uptake transport, including OATP1A2. EGCG and related green tea catechins inhibit OATP-mediated uptake in the gut, lowering fexofenadine absorption while leaving elimination half-life largely unchanged.

Recommendation. Take fexofenadine with water, not green tea extract or concentrated catechin products. Separate green tea extract from fexofenadine by at least 4 hours, and be consistent if you use both. If allergy control worsens after starting green tea extract, stop the extract or switch timing and reassess symptoms.

Minimum separation. 240

Sources (2)

Stack Score

How this pair moves the number.

Effect on the composite score

If both Fexofenadine and Green Tea Extract 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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