NutriStack
DIM and Tamoxifen, a conflict.
DIM decreases endoxifen (tamoxifen's active metabolite) levels through CYP enzyme induction, potentially reducing tamoxifen's cancer-preventive benefit.
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
- DIM and Tamoxifen
- Pair type
- Conflict
- Evidence (highest tier)
- Moderate
- Source citations
- 2 sources
- Stack Score effect
- −10 to your Stack Score (per scored conflict row).
- Scope
- Supplement × Supplement
- Last verified
- May 30, 2026
Conflict · Moderate evidence
Conflict
What is happening. DIM decreases endoxifen (tamoxifen's active metabolite) levels through CYP enzyme induction, potentially reducing tamoxifen's cancer-preventive benefit.
Mechanism. DIM induces CYP1A2 (113-fold) altering tamoxifen metabolism and reducing endoxifen.
Recommendation. Do NOT combine without oncologist approval. DIM may reduce tamoxifen effectiveness.
Sources (2)
- DIM + tamoxifen RCT, reduced endoxifen PMID 28560655
- DIM induces CYP3A4 via PXR PMID 25542144
Stack Score
How this pair moves the number.
Effect on the composite score
If both DIM and Tamoxifen are in the same stack, this pair applies −10 to your Stack Score (per scored conflict row).
The full algorithm, the clamping rules, and four worked stacks are documented at /methodology/stack-score.
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