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Study on the Effects of Estetrol Monohydrate on Hair Growth in Postmenopausal Women with Hair Loss

InvestigationalNo placebo
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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying the effects of a treatment on female pattern hair loss in postmenopausal women. The treatment being tested is a 20 mg tablet of estetrol monohydrate, a chemical compound, and it will be compared to a placebo. The purpose of the study is to assess how this treatment influences hair growth parameters over a period of six months.

Participants in the study will be randomly assigned to receive either the estetrol monohydrate tablet or a placebo. The study is designed to be double-blind, meaning neither the participants nor the researchers will know who is receiving the actual treatment or the placebo. The main focus will be on measuring changes in hair growth, specifically looking at the number and width of non-vellus hair, which is the thicker type of hair, at the end of the study period. Additionally, the study will evaluate the safety of the treatment and its effects on the endometrium, which is the lining of the uterus, as well as monitor any vaginal bleeding in participants who have not had a hysterectomy.

The study will last for approximately six months, during which participants will be asked to maintain their usual hair care routines and hairstyles. Regular assessments will be conducted to monitor hair growth and overall health. The study aims to provide valuable insights into the potential benefits and safety of estetrol monohydrate for improving hair growth in postmenopausal women experiencing hair loss.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial visit and randomization

    Upon joining the study, participants will attend an initial visit. During this visit, participants will be randomly assigned to receive either the study medication, estetrol monohydrate (E4) 20 mg, or a placebo. The assignment is double-blind, meaning neither the participant nor the study team will know which treatment is being administered.

  2. Step 2

    Medication administration

    Participants will take one film-coated tablet orally each day. The tablet will either contain estetrol monohydrate (E4) 20 mg or a placebo, depending on the randomization. This daily regimen will continue for a period of 6 months.

  3. Step 3

    Regular follow-up visits

    Throughout the study, participants will attend regular follow-up visits. These visits will occur at specified intervals to monitor health and assess the effects of the treatment. During these visits, various assessments will be conducted, including hair growth measurements and general health evaluations.

  4. Step 4

    Hair growth assessment

    At week 22, a detailed assessment of hair growth will be conducted. This will involve measuring the number and width of non-vellus hair in a specific target area on the scalp. These measurements will help determine the influence of the treatment on hair growth.

  5. Step 5

    Safety evaluations

    Safety evaluations will be conducted throughout the study to monitor any potential side effects. This includes regular checks of vital signs, physical examinations, and laboratory tests. Participants will also be asked about any vaginal bleeding or spotting if applicable.

  6. Step 6

    End of study visit

    At the end of the 6-month period, participants will attend a final study visit. During this visit, a comprehensive evaluation will be conducted to assess the overall effects of the treatment. Participants will return any unused medication and complete final questionnaires.

Who can join the trial?

15 criteria

  • Must be a postmenopausal woman experiencing symptoms like hot flashes.
  • Age between 40 to 65 years at the time of joining the study.
  • Must have postmenopausal status, which means:
    • For women who have not had a hysterectomy: At least 12 months without a period and specific hormone levels, or at least 6 months after having both ovaries removed.
    • For women who have had a hysterectomy: Specific hormone levels, or at least 6 months after having both ovaries removed.
    • If you have had a hysterectomy or both ovaries removed, the surgery must have been done at least 6 months before the study starts.
    • For women who have not had a hysterectomy: The thickness of the lining of the uterus must be 4 mm or less, as checked by an ultrasound.
    • Body mass index (BMI) should be between 18.5 and 35. BMI is a measure of body fat based on height and weight.
    • A recent mammogram showing no significant disease is required.
    • Must be in good physical and mental health, as judged by the study doctor.
    • Must be able to understand and follow the study requirements and instructions.
    • Must be willing to complete study diaries and questionnaires.
    • Must have a decrease in hair density on the top of the scalp compared to the sides and back, as measured by a specific scale.
    • Must be willing to keep the same hairstyle, hair length, and hair color throughout the study.
    • Must agree to continue using the same hair care products and routine during the study.
    • Must agree to maintain the same diet and supplement routine.

Who cannot join the trial?

4 criteria

  • Participants must be postmenopausal women experiencing hot flashes or other menopausal symptoms.
  • Participants should not have had a hysterectomy (surgical removal of the uterus).
  • Participants must be female, as the study does not include male subjects.
  • Participants should not be part of a vulnerable population, which means they should be able to make decisions for themselves and not be in a situation where they are easily influenced or at risk.
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Investigated drugs

Estetrol (E4) is a medication being studied for its potential to help with hair growth in postmenopausal women who are experiencing hair loss. This study is looking at how well Estetrol can improve hair growth by measuring the number and thickness of hairs in a specific area of the scalp. The goal is to see if Estetrol can make a noticeable difference in hair growth compared to not using the medication. Additionally, the study is also checking if Estetrol is safe to use and if it has any effects on the lining of the uterus or causes any changes in menstrual bleeding patterns in women who have not had a hysterectomy.

What is already known about the treatment

Estetrol (E4) – Estetrol is administered orally in the form of a tablet. It is currently being studied in clinical trials, particularly for its effects on hair growth in postmenopausal women experiencing female pattern hair loss. The main therapeutic indication for Estetrol in this context is to improve hair growth parameters, such as hair count and hair width, over a 6-month period. At the molecular level, Estetrol works by interacting with estrogen receptors, which can influence various physiological processes, including hair growth. It is classified pharmacologically as a selective estrogen receptor modulator (SERM).

Investigated diseases

Female Pattern Hair Loss – Female pattern hair loss is a common form of hair thinning in women, characterized by a gradual reduction in hair density. It typically begins with a widening of the part line and progresses to diffuse thinning on the top of the scalp. The condition is influenced by genetic and hormonal factors, particularly the action of androgens. Over time, hair follicles shrink, leading to shorter and finer hair strands. The progression of hair loss can vary, with some women experiencing slow changes over decades, while others may notice more rapid thinning. The condition does not usually result in complete baldness.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IITrial ID2024-517890-26-00Estimated enrolment60 patientsSponsorEstetra

sourced from the EU Clinical Trials Register and site verification

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On this site, “treatment” means an investigational medicine being studied in a clinical trial. Its safety and efficacy for the use being studied have not yet been confirmed, some participants may receive a placebo or a comparator medicine, and taking part does not guarantee any health benefit. The decision to take part is made by the doctor at the research site. This site is for information only and does not replace medical advice.

This service is not affiliated with the European Commission, the EMA, or the official CTIS system. Most information comes from publicly available international clinical-trial registries, supplemented by data from academic sites, national regulators and commercial sponsors. On this site, “treatment” and “therapy” mean a medicine being tested in a clinical trial. Its safety and effectiveness in the use being studied are not yet confirmed, some participants may receive a placebo or a comparator, and taking part does not guarantee a health benefit. The doctor at the research site decides who can take part. This site provides information, not medical advice. Certain content and visual elements on this website have been generated or enhanced using artificial intelligence (AI).