Phase 4
N=36
Effects of St. John's Wort on the Oral Contraceptive Hormone Levonorgestrel
Contraception
Bottom Line
View on ClinicalTrials.gov: NCT00131885 ↗Enrolled (actual)
36
Serious AEs
0.0%
Results posted
Jun 2010
Primary outcome: Primary: Area Under the Concentration Versus Time Curve for 0 to 24 Hours After Drug Administration, Done Between Days 9 and 12 of the Menstrual Cycle at Time 1 (Before) and Time 2 (During Treatment With St. John's Wort or Placebo) — 586.3; 379.4; 339.4; 253.3 ng*hr/mL
Study Design & Population
- Study type
- Interventional
- Phase
- Phase 4
- Interventions
- Placebo Control (Placebo Herb) (Dietary_supplement); St. John's Wort (Dietary_supplement); Levonorgestrel (Drug)
- Age
- Adult · 18+ yrs
- Sex
- Female
- Sponsor
- University of Utah
- Primary completion
- May 2008
Outcome Measures
| Outcome | Result | p-value |
|---|---|---|
| PRIMARY Area Under the Concentration Versus Time Curve for 0 to 24 Hours After Drug Administration, Done Between Days 9 and 12 of the Menstrual Cycle at Time 1 (Before) and Time 2 (During Treatment With St. John's Wort or Placebo) |
586.3; 379.4; 339.4; 253.3; 478.2; 317.4 | — |
| PRIMARY Number of Participants With Progesterone Levels Above 3.0 ng/ml at Time 1 (Baseline) and Time 2 (After Intervention With St John's Wort or Placebo). |
3; 1; 1; 3; 3; 2 | — |
| PRIMARY Clearance (L/hr) of Levonorgestrel Over 24 Hours for Each Dosage Group and Each Study Session. |
4.06; 4.93; 6.39; 6.85; 4.64; 5.63 | — |
| SECONDARY Mean Levels of Follicle-stimulating Hormone Drawn at Weekly Intervals Until Next Menses |
14.9; 14.0; 15.8; 13.9; 14.5; 14.7 | — |
| SECONDARY Mean Levels of Estradiol-17b (E2) Drawn at Weekly Intervals Until Next Menses |
133.3; 137.2; 131.1; 103.5; 142.2; 154.7 | — |
| SECONDARY Mean Levels of Luteinizing Hormone, Drawn at Weekly Intervals Until Next Menses |
24.7; 20.9; 26.4; 25.3; 35.1; 30.2 | — |
Summary
This study will determine the effects of St. John's wort, a common herbal remedy, on metabolism of the female contraceptive hormone levonorgestrel.
Eligibility Criteria
Inclusion Criteria
- Body mass index (BMI) between 20 and 25
- Regular menstrual cycles for at least 3 months prior to study entry
Exclusion Criteria
- Current use of foods, herbs, vitamins, over-the-counter supplements, or any medications that could alter pharmacokinetics of other drugs
- Medical contraindications to the use of contraceptives
Data sourced from ClinicalTrials.gov (NCT00131885). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication.