St. John's wort may alter how your body handles other drugs

NCT ID NCT03482817

First seen Jun 27, 2026 · Last updated Jun 27, 2026

Summary

This study investigates how a specific extract of St. John's wort (Ze 117) influences key enzymes and transporters that process many common medications. Twenty healthy volunteers take a cocktail of probe drugs alone and then with St. John's wort to measure changes in drug levels. The goal is to understand potential interactions that could affect the safety and effectiveness of other medicines.

What this could mean

Our plain-language read of the trial. This is informational only — not medical advice or a prediction.

Active substance

St. John's wort dry extract Ze 117

What this could lead to

If successful, this could help predict how St. John's wort interacts with other medications, improving safe co-prescribing.

What could go wrong

This is a small, early-phase study in healthy volunteers, so results may not apply to patients or predict real-world interactions.

Disclaimer Read more

This is a summary of the original study . Summaries may miss details or leave out important information. Before applying or accepting participation, make sure you have read and understood the full study. Curemydisease.com takes no responsibility whatsoever for anything missed, misunderstood, or acted upon as a result of our summary — we know it does not capture everything.

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As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

Contacts and locations

Locations

  • Nuvisan GmbH

    Neu-Ulm, Germany