CBG Normalization After Discontinuation of COC's

April 18, 2026 updated by: Annemieke Heijboer, Academisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA)

The Effect of Discontinuing Estrogen Containing Oral Contraceptives on Corticosteroid-binding Globulin and Total Cortisol Concentrations

In this study, the investigators aim to examine after which duration corticosteroid-binding globulin (CBG) and total cortisol concentrations return to normal after cessation of the combined oral contraceptive pill in healthy women.

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.

Detailed Description

Use of exogenous estrogens is known to increase corticosteroid-binding globulin (CBG) levels and thereby total cortisol concentrations measured in serum. When endocrine function are performed to assess hypothalamus-pituitary-adrenal function, total cortisol levels are measured in serum. When women use exogenous oral estrogen, for instance the birth control pill, the current recommendation is to discontinue oral estrogens for at least 6 weeks before the test. This may introduce diagnostic delay and inconvenience for the patient. The duration it takes for CBG concentrations to return to normal, have not been studied in vivo as far as known by the investigators.

The main objective of this prospective observational study is to determine the duration in which CBG and total cortisol concentrations return to normal after cessation of oral estrogen. Secondary objectives are to examine the normalization of other hormone binding proteins and their corresponding hormones (VDBP & vitamin D; TBG & T4, T3; SHBG & testosterone; IGFBP3 & IGF1).

The study population consists of healthy women aged ≥18 years old, who are planning to stop using combined oral contraceptives (COCs) for at least six weeks. The study consists of 8 weekly blood samples. The first blood sample will be performed one week before cessation of COCs, the second one at the moment of cessation and after cessation the next six weekly blood samples will be taken.

After establishing when values return to normal, doctors have a better idea of how many weeks after stopping COCs, blood results can be properly assessed. If the duration were shorter than six weeks, this would mean less inconvenience for women undergoing dynamic function tests who would have to stop taking their contraceptive pill.

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.
Observational

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.
24

Contacts and Locations

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

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • Netherlands
      • Amsterdam, Netherlands, 1105 AZ
        • Amsterdam UMC

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

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Adult females who are planning to discontinue estrogen containing oral contraceptives for a duration of at least 6 weeks.

Description

Inclusion Criteria:

  • ≥18 years old
  • Using oral combined contraceptives of any kind and dosage
  • Planning to stop COC use shortly for at least 6 weeks (out of own reasons such as a pregnancy wish or choice for non-hormone based contraceptives)
  • COC use for at least 3 consecutive weeks before the discontinuation
  • Ability to provide informed consent
  • Ability to speak and understand Dutch

Exclusion Criteria:

  • Switching to other hormonal contraceptives after taking the COC pill (e.g. progesterone containing contraceptives such as the Mirena IUD, contraceptive implants) directly after the discontinuations
  • Contra-indications to quit COC

  • Biological factors that affect CBG concentrations, including:

    • Illnesses interfering with CBG levels (severe liver or kidney disease, active malignancy, hyperthyroidism)
    • Use of insulin, systemic exogenous glucocorticoids, mitotane, selective estrogen receptor modulators (SERMs)
    • Pregnancy during study period after discontinuation of COCs

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

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
Time to normalization of CBG and total cortisol concentrations
Time Frame: 8 weeks
Time in weeks until plateau is reached.
8 weeks

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
Time to normalization of VDBP, vitamin D, TBG, T4, T3, SHBG, testosterone, IGFBP3 and IGF1
Time Frame: 8 weeks
Time in weeks until plateau is reached.
8 weeks

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Estradiol concentration
Time Frame: 8 weeks
Used for determining menstrual cycle
8 weeks
Progesterone concentration
Time Frame: 8 weeks
Used for determining menstrual cycle
8 weeks
LH concentration
Time Frame: 8 weeks
Used for determining menstrual cycle
8 weeks
FSH concentration
Time Frame: 8 weeks
Used for determining menstrual cycle
8 weeks
Occurrence of vaginal blood loss
Time Frame: 8 weeks
Used for determining menstrual cycle
8 weeks
Albumin concentration
Time Frame: 8 weeks
8 weeks
Prolactin concentration
Time Frame: 8 weeks
8 weeks
fT3 and fT4 concentration
Time Frame: 8 weeks
8 weeks
TSH concentration
Time Frame: 8 weeks
8 weeks
HCG concentration
Time Frame: Measured at 6th week after cessation of COCs
Measured at 6th week after cessation of COCs

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.
Academisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA)

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Annemieke C Heijboer, Prof. Dr., Amsterdam UMC location Vrije Universiteit Amsterdam, Department of Laboratory Medicine, Endocrine Laboratory, Boelelaan 1117, Amsterdam, The Netherlands

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.
February 5, 2025

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.
November 18, 2025

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.
November 18, 2025

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).
January 24, 2025

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.
January 29, 2025

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.
January 31, 2025

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.
April 22, 2026

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.
April 18, 2026

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.
April 1, 2026

More Information

Terms related to this study

Keywords

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.
  • NL87932.018.24

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

product manufactured in and exported from the U.S.

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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