NutriStack
Nifedipine and St. John's Wort, a conflict.
St. John's Wort induces CYP3A4, which is the primary metabolic pathway for nifedipine. This can dramatically reduce nifedipine levels and blood pressure control.
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
- Nifedipine and St. John's Wort
- Pair type
- Conflict
- Evidence (highest tier)
- Strong
- Source citations
- 1 source
- Stack Score effect
- −10 to your Stack Score (per scored conflict row).
- Scope
- Supplement × Prescription
- Last verified
- May 30, 2026
Conflict · Strong evidence
Conflict
What is happening. St. John's Wort induces CYP3A4, which is the primary metabolic pathway for nifedipine. This can dramatically reduce nifedipine levels and blood pressure control.
Mechanism. Nifedipine undergoes extensive CYP3A4-mediated first-pass metabolism. CYP3A4 induction by SJW can reduce nifedipine AUC by >50%.
Recommendation. Avoid St. John's Wort with nifedipine. A documented case showed a patient's BP rose from controlled to 180/100 after starting SJW.
Stack Score
How this pair moves the number.
Effect on the composite score
If both Nifedipine and St. John's Wort 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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