Supplement × Prescription·a caution·Moderate evidence
St. John's Wort can induce drug-metabolizing enzymes and transporters and may lower Pioglitazone exposure or undermine therapy.
Every entry follows the same shape: what is happening, the mechanism, and the recommendation.
What is happening. St. John's Wort can induce drug-metabolizing enzymes and transporters and may lower Pioglitazone exposure or undermine therapy.
Mechanism. Hyperforin induces CYP3A4 and P-glycoprotein, which can reduce exposure to susceptible drugs.
Recommendation. Avoid starting or stopping St. John's Wort without prescriber review while taking Pioglitazone.
Effect on the composite score
If both Pioglitazone and St. John's Wort are in the same stack, this pair applies −5 to your Stack Score (per scored caution row).
The full algorithm, the clamping rules, and four worked stacks are at /methodology/stack-score.
Every claim on this page is cited. PMIDs link straight to PubMed.
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NutriStack is an informational and organizational tool, not a medical service, and not a substitute for professional advice. Always consult a qualified healthcare professional before starting, stopping, or changing any supplement or medication.
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