# Effects of St. John's Wort on the Oral Contraceptive Hormone Levonorgestrel

> **NCT00131885** · PHASE4 · COMPLETED · sponsor: **University of Utah** · enrollment: 36 (actual)

## Conditions studied

- Contraception

## Interventions

- **DIETARY_SUPPLEMENT:** Placebo Control (Placebo Herb)
- **DIETARY_SUPPLEMENT:** St. John's Wort
- **DRUG:** Levonorgestrel

## Key facts

- **NCT ID:** NCT00131885
- **Lead sponsor:** University of Utah
- **Sponsor class:** OTHER
- **Phase:** PHASE4
- **Study type:** INTERVENTIONAL
- **Status:** COMPLETED
- **Start date:** 2005-08
- **Primary completion:** 2008-05
- **Final completion:** 2008-05
- **Target enrollment:** 36 (ACTUAL)
- **Last updated:** 2023-11-13

## Collaborators

- [object Object]

## Primary source

ClinicalTrials.gov registry: https://clinicaltrials.gov/study/NCT00131885

## Citation

> US National Library of Medicine, ClinicalTrials.gov registration NCT00131885, "Effects of St. John's Wort on the Oral Contraceptive Hormone Levonorgestrel". Retrieved via AI Analytics 2026-06-24 from https://api.ai-analytics.org/clinical/NCT00131885. Licensed CC0.

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