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

This study has been completed.
Information provided by:
National Center for Complementary and Integrative Health (NCCIH)
ClinicalTrials.gov Identifier:
First received: November 5, 2001
Last updated: August 17, 2006
Last verified: July 2006
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.

Condition Intervention
Drug: hypericum perforatum

Study Type: Interventional
Study Design: Allocation: Non-Randomized
Endpoint Classification: Pharmacokinetics/Dynamics Study
Intervention Model: Single Group Assignment
Masking: Single Blind
Primary Purpose: Treatment
Official Title: Effects of Hypericum Perforatum on Effectiveness of Oral Contraceptives

Resource links provided by NLM:

Further study details as provided by National Center for Complementary and Integrative Health (NCCIH):

Estimated Enrollment: 25
Study Start Date: January 2002
Estimated Study Completion Date: January 2004
Detailed Description:
See Brief Summary

Ages Eligible for Study:   18 Years to 40 Years
Genders Eligible for Study:   Female
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Women taking or willing to take low dose oral contraceptives for 5 months
  • No contraindications to hormonal contraception
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00026013

United States, New York
Columbia University Department of Obstetrics & Gynecology
New York, New York, United States, 10032
Sponsors and Collaborators
National Center for Complementary and Integrative Health (NCCIH)
Principal Investigator: Patricia Murphy, DrPh Columbia University
  More Information

No publications provided

ClinicalTrials.gov Identifier: NCT00026013     History of Changes
Other Study ID Numbers: R21 AT000836-01
Study First Received: November 5, 2001
Last Updated: August 17, 2006
Health Authority: United States: Federal Government

Keywords provided by National Center for Complementary and Integrative Health (NCCIH):
hormonal contraception
herbal remedies
hypericum perforatum
contraceptive effectiveness

Additional relevant MeSH terms:
Contraceptive Agents
Contraceptives, Oral
Contraceptive Agents, Female
Pharmacologic Actions
Physiological Effects of Drugs
Reproductive Control Agents
Therapeutic Uses

ClinicalTrials.gov processed this record on November 25, 2015