Effects of St. John's Wort on the Effectiveness of Oral Contraceptives

Effects of Hypericum Perforatum on Effectiveness of Oral Contraceptives

Status

Completed

Phases

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT00026013

Enrollment

Registered

2001-11-06

Start date

2002-01-31

Completion date

2004-01-31

Last updated

2006-08-18

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Contraception

Keywords

contraception, hormonal contraception, herbal remedies, hypericum perforatum, contraceptive effectiveness

Brief summary

The purpose of this study is to evaluate the effects of a common herbal remedy, St. John's Wort, on the effectiveness of birth control pills. St. John's Wort has recently been shown to increase metabolism of some drugs. If it could increase metabolism of oral contraceptives as well, it may increase the risk of contraceptive failure and unintended pregnancy. Study participants will be evaluated for risk of ovulation on oral contraceptives before and during simultaneous therapy with St. John's Wort.

Detailed description

See Brief Summary

Interventions

DRUGhypericum perforatum

Study design

Allocation

NON_RANDOMIZED

Intervention model

SINGLE_GROUP

Primary purpose

TREATMENT

Masking

SINGLE

Eligibility

Sex/Gender

FEMALE

Age

18 Years to 40 Years

Healthy volunteers

Yes

Inclusion criteria

* Women taking or willing to take low dose oral contraceptives for 5 months * No contraindications to hormonal contraception

Countries

United States

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026