About the Study
The E4Comfort Study is evaluating an oral study medication to see if it may reduce hot flashes and night sweats in post-menopausal women. Estetrol, the study medication, is a synthetic form of the naturally occurring estrogen.
How Can I Qualify?
You may be able to participate if you:
- Are a post-menopausal woman aged 40-65 years
- Experience moderate-to-severe hot flashes or night sweats
- Do not have a history of cancer, diabetes, or heart disease
Additional requirements will apply. The study staff can provide more details.
Participation in this study is completely voluntary, and you may withdraw from the study at any time.
Why Participate?
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All study-related care will be provided at no cost
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The study staff will closely monitor you and your symptoms
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You will be helping to advance knowledge of women’s health
About Hot Flashes and Night Sweats
Hot flashes and night sweats can be uncomfortable and disruptive. They are, however, a real medical condition that can be treated. If you have moderate-to-severe hot flashes, consider participating in a clinical research study.
What happens during a hot flash?
A hot flash is a sudden sensation of heat in the face, neck, chest, or all over that may cause you to become flushed and sweat heavily. Hot flashes that happen at night are called night sweats.
Up to 80% of women experience hot flashes during menopause.*
Hot flashes may be caused by fewer hormones, such as estrogen and progesterone, being produced during menopause. These changes in hormone levels can affect your body’s temperature-control system.
*Avis, et al., JAMA Intern Med. 2015;175(4):531-539. doi:10.1001/jamainternmed.2014.8063

Frequently Asked Questions
About Clinical Research Studies
A clinical research study, also known as a clinical trial, is a scientific study that evaluates the safety and effectiveness of a study medication. Qualified doctors, nurses, and other medical professionals are responsible for conducting the study.
It is only through the completion of clinical research studies that study medications can be evaluated and, if proven safe and effective, approved for a particular use. Different regulatory bodies in different countries will provide this approval after a thorough review. In the US, the regulatory body is the Food and Drug Administration (FDA). Prescription medications in use today were first shown to be safe and effective during clinical research studies.
To help ensure that a clinical research study is ethical and that patients’ rights are protected, Institutional Review Boards (IRB) or Ethics Committees (EC) review and approve study protocols that detail all aspects of how the study is conducted. In addition, study monitors, also known as clinical research associates, visit the study sites to confirm that the study protocol procedures and research study requirements and regulations are being followed throughout the study. Health authorities may also inspect the study sites to ensure the safety and rights of the study participants in a clinical research study and the integrity of the research study objectives.
If you are interested in taking part in the study, you will be asked to complete a pre-screening form that will determine whether or not you meet the basic requirements of the study. If you do, the study staff will review your medical history and current medical status against the eligibility criteria of the study. You may also be asked to provide information from your medical records. The study staff then determines who will take part in the study. Only participants who meet all required eligibility criteria for a clinical research study may participate.
A study medication, sometimes called an investigational medication or investigational drug, is a product being tested in a clinical research study that has not yet been approved by appropriate regulatory or health authorities (in the US, that is the FDA) for medical use. Clinical research studies are one of the last steps before an investigational medication receives regulatory approval. Prescription medications in use today were first shown to be safe and effective during clinical research studies.
About the E4Comfort Study
Estetra SPRL of Mithra Pharmaceuticals is the study sponsor. Mithra is a company that’s dedicated to providing innovation and choice in women’s health, with a particular focus on contraception and menopause.
The purpose of the E4Comfort Study is to evaluate whether estetrol is safe and effective in reducing hot flashes and night sweats in post-menopausal women.
Your participation in the E4Comfort Study may last up to 16 months. The study staff can provide you with more information about the study visits.
Before you agree to participate, the study staff will review with you all aspects of the study, including required study assessments. You will be given a document called an “Informed Consent Form” that provides, in writing, the study’s purpose, assessments, procedures, benefits, risks, and precautions. You will have the opportunity to ask questions and are encouraged to speak with your own doctor to decide if taking part is right for you.
Study Medication
The name of the study medication is estetrol. Estetrol is a synthetic form of the naturally occurring estrogen.
A placebo looks like the study medication but is an inactive substance. It is used in clinical research studies to determine if the study medication is more effective than no treatment at all. The study staff can give you more information about whether or not you may receive placebo during the study.
Privacy, Stopping Participation, Costs and Permission
The study staff respects and protects your privacy and follows all federal regulations related to privacy. We will not share your personal information, except as required by law, and your personal information will be stored with codes that do not identify you. The Informed Consent Form will provide more information about how your privacy will be maintained.
Yes. Your participation in the clinical research study is entirely voluntary, and you may withdraw at any time. If you decide to withdraw early from the study, you will be asked to notify the study staff so you can complete a final visit and return any unused study medication.
No. There is no charge for taking part in the study. All study-related care is provided at no charge.
No. You will not be paid for taking part in the study. You may, however, be eligible for reimbursement of travel expenses relating to your study visits.
No. Your doctor does not have to give his/her permission for you to take part in the study. However, either you or the study doctor, with your permission, may contact your doctor to discuss your participation before you begin and keep him/her up-to-date about your progress.