Red Clover Botanical Dietary Supplements - Metabolism and Safety in Women

May 1, 2021 updated by: Elena Barengolts, University of Illinois at Chicago
Human safety studies were carried out to test whether red clover botanical dietary supplements used by peri- and post-menopausal women are safe to use with Food and Drug Administration (FDA)-approved drugs. To test this, a red clover dietary supplement (previously tested in women at the University of Illinois at Chicago without any harmful effects) was given with four selected FDA-approved drugs to determine if the red clover supplement can increase or decrease how these medications are absorbed, metabolized and excreted by the human body. Preclinical studies predicted that the red clover supplement might affect the metabolism or break down of these probe drugs.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

At the start of a study, subjects were administered low doses of a mixture of four FDA-approved drugs (caffeine, tolbutamide, dextromethorphan, and alprazolam), and serial blood samples were drawn and analyzed for the concentration of each drug over time. Afterwards, participants took the red clover dietary supplement twice orally daily for 14 days to allow for potential inhibition or induction of drug metabolizing enzymes and transporters. Thereafter, the same drugs were taken again to obtain a second measure of drug concentrations in blood over time. Changes in the concentration-time curve values for each probe drug obtained before and after ingestion of the supplement were evaluated to determine if metabolism of the probe drugs was impacted by the red clover dietary supplement.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
20

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Illinois
      • Chicago, Illinois, United States, 60612
        • University of Illinois at Chicago

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

40 years to 79 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Female

Description

Inclusion Criteria:

  • healthy peri- and post-menopausal women ages 40 - 79
  • non-smokers
  • no-significant medical conditions as assessed by subject-reported medical history, physical examination and blood and urine chemistry screens
  • no medical condition that requires chronic use of medication

Exclusion Criteria:

  • known allergies or hypersensitivity to caffeine, dextromethorphan, sulfonylureas (tolbutamide), benzodiazepines, or red clover
  • positive pregnancy test
  • use of hormone therapy within 8 weeks of study initiation for oral agents, 4 weeks for transdermal or other topical agents
  • use of caffeine products 7 days before study participation or during the study
  • use of citrus products 7 days before study participation or during the study
  • other prescription (with the exception of the Mirena® IUD) or non-prescription medicines within the 2 weeks prior to study initiation or during the study
  • chronic diseases, such as inflammatory bowel disease, that could alter the absorption or metabolism of the probe substrates
  • unwillingness to comply with study requirements
  • current participation in another clinical trial
  • CYP2D6 deficiency based on phenotyping at screening
  • smoker
  • red clover or soy intake (whether as a botanical dietary supplement, food, drink or otherwise) within the previous two weeks and during the study
  • use of any dietary supplements within the last 2 weeks prior to study initiation and during the study
  • extreme obesity (defined as >40 BMI)
  • alcohol or drug abuse
  • chronic diseases such as diabetes.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Trifolium pratense
Red clover extract; 2 gelatin capsules (398 mg extract) per day for 14 days
Dietary supplement: Trifolium pratense
Red Clover extract standardized to isoflavone content.
Other Names:
  • Red Clover

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Area Under the Curve (AUC)
Time Frame: baseline and 14 days
Concentrations of probe drugs from blood draws at the conclusion of the 14-day intervention were used to calculate areas under the (extrapolated) concentration-time curve to determine any changes compared to pre-intervention.
baseline and 14 days

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Apparent Clearance
Time Frame: baseline and 14 days
Concentrations of probe drugs from blood draws at the conclusion of the 14-day intervention were used to calculate changes in apparent clearance of each probe drug compared to pre-intervention.
baseline and 14 days
Peak Concentration
Time Frame: baseline and 14 days
Concentrations of probe drugs from blood draws at the conclusion of the 14-day intervention were used to calculate changes in peak concentrations of probe drugs to compared to pre-intervention concentrations.
baseline and 14 days
Time for Peak Concentration
Time Frame: baseline and 14 days
Concentrations of probe drugs from blood draws at the conclusion of the 14-day intervention were used to calculate changes in time for peak concentration of probe drugs compared to pre-intervention concentrations.
baseline and 14 days
Drug Half-life
Time Frame: baseline and 14 days
Concentrations of probe drugs from blood draws at the end of the 14-day intervention were used to calculate half-lives of probe drugs to determine any changes compared to pre-intervention.
baseline and 14 days

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Illinois at Chicago

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
September 21, 2017

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
April 29, 2020

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
July 1, 2020

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
June 29, 2017

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 29, 2017

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 2, 2017

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 6, 2021

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 1, 2021

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2021

More Information

Terms related to this study

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 2017-0436

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

No

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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