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Female ContraceptionPhase 3WOMEN&MoreNCT06394999

Efficacy, Safety, and Acceptability of Mifepristone 50 mg Once-weekly as a Contraceptive

A Phase 3 study testing Mifepristone 50 mg in people with Female Contraception, run by Leiden University Medical Center at 14 sites in Netherlands.

Active, not recruiting

Under way, not looking for participants. Everyone needed has enrolled. The study is still running.

Official record
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Trial summary

Participants in the study will use mifepristone 50 mg once-a-week for one year as a contraceptive. With this, we want to confirm that the chances of getting pregnant while using this contraceptive are very small. Read more about this study

Who is it for?
Ages 18 to 35 years, women onlyHealthy volunteers can take part
Conditions the study is for
Female Contraception
What is being tested?
Mifepristone 50 mg
Type of treatment
Pill or oral medicine
Could I receive a placebo?
No, everyone receives an active treatment
How many people
615 participants
Where
14 sitesNetherlands
Study dates
2 May 2025to 1 Jan 2028
Phase
Phase 3
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 35 years
  • Women only
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Age 18-35 at the moment of signing the informed consent.
  • In case of 30 years or older, prior HPV or pap-test.
  • Understand and speak Dutch or English.
  • Willing to use mifepristone as the only method of contraception for 12 months.
  • Able to take oral medication and willing to adhere to the study protocol.
  • Have unprotected vaginal heterosexual intercourse with a non-sterilized partner at least once a month.
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  • BMI < 35 kg/m2.
  • Willing to fill in a daily diary on the smartphone or computer and five times an on-line questionnaire.
  • Able to participate in the scheduled visits and comply with the study protocol.
  • Provide informed consent about participating in study and provide permission to request medical data in the event of complications or pregnancy.
  • In case of not using hormonal contraceptives, menstrual cycle of 21-35 days.
  • In case of Depo-Provera (3 month injectable) at least 3 cycles of 21-35 days after stop.
  • In case of necessary progesterone treatment, be willing to use condoms temporarily.

Who cannot join

  • Currently pregnant or breast-feeding.
  • Desire to become pregnant within the following 12 months.
  • Signs of current endometritis, incomplete abortion after miscarriage or induced abortion, or retained pla-cental rests after delivery.
  • Undiagnosed post-coital bleeding or unscheduled bleeding (spotting with COC, patch, vaginal ring, hormo-nal IUD, implant allowed).
  • Known subfertility or history of ectopic pregnancy, unless intra-uterine pregnancy afterwards, or grade 3-4 endometriosis proven by laparoscopy.
  • History of gastric reduction or gastric bypass or use of weight-loss medicines.
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  • Previous or current liver illness, previous or current infection affecting the liver (such as Hepatitis) or mod-erately abnormal liver enzymes at screening (ALAT, ASAT or bilirubin > 2 ULN).
  • Current or previous cancer or DCIS.
  • Family history of endometrial cancer, except BRCA genome mutation.
  • Known allergy to mifepristone.
  • Using non-dermal corticosteroids or any drugs that may interact with mifepristone. These include hydan-toins (e.g. phenytoin), barbiturates (e.g. phenobarbital), primidone, carbamazepine, rifampicin, oxcarbaze-pine, topiramate, rifabutin, felbamate, ritonavir, nelfinavir, griseofulvin and products containing St. John's wort (Hypericum perforatum).
  • Treatment with another investigational drug or participating in another intervention study, unless the prin-cipal investigators agree.
  • Undiagnosed reason for severe anemia or increased creatinine.
  • Abnormal previous PAP smear > pap II without colposcopic evaluation or untreated HSIL.
  • Systolic blood pressure ≥ 180 mmHg and/or diastolic ≥ 110 mmHg (hypertension with medical treatment allowed).
  • Intracavitary abnormalities on vaginal ultrasound, including intracavitary polyps or myomas, endometrium > 15 mm, or an obvious sign of hydrosalpinx.
  • Previous participation in the WOMEN\&More trial.

Trial locations and contacts

14 sites in 1 country.

14 sites in 1 country

Netherlands14 sites

  • Noordwest Ziekenhuisgroep

    Alkmaar, 1815 JD

  • Ziekenhuisgroep Twente

    Almelo, 7609 PP

  • Flevoziekenhuis

    Almere Stad, 1315 RA

  • Amsterdam Universitair Medische Centra

    Amsterdam, 1105 AZ

  • Medisch Spectrum Twente

    Enschede, 7512 KZ

  • Admiraal De Ruyter Ziekenhuis

    Goes, 4462 RA

  • Martini Ziekenhuis

    Groningen, 9728 NZ

  • Medisch Centrum Leeuwarden

    Leeuwarden, 8934 AD

  • Leiden University Medical Center

    Leiden, 2333 ZA

  • Maastricht Universitair Medisch Centrum

    Maastricht, 6229 HX

  • Canisius Wilhelmina Ziekenhuis

    Nijmegen, 6532 SZ

  • Franciscus Gasthuis

    Rotterdam, 3045 PM

  • Diakonessenhuis

    Utrecht, 3582 KE

  • Maxima Medisch Centrum

    Veldhoven, 5504 DB

Other trials in Netherlands

About this study

Official title: Prospective Phase III Multi-center Open-label Study of the Efficacy, Safety, and Acceptability of Mifepristone 50 mg Once-weekly as a Contraceptive

Participants in the study will use mifepristone 50 mg once-a-week for one year as a contraceptive. With this, we want to confirm that the chances of getting pregnant while using this contraceptive are very small. We also want to demonstrate that the use of mifepristone is safe, and it does not lead to any severe health problems. We expect fewer side effects compared to other frequently used contraceptives with hormones. Mifepristone does not contain these hormones. It is important to know how people experience that use of one tablet a week.

Read the detailed description

Mifepristone 50 mg, a progesterone receptor modulator, is a proven safe emergency contraceptive and a promising new weekly contraceptive. As mifepristone does not contain estrogens or progestogens, we anticipate users will not experience the undesirable side effects and health risks of current hormonal contraceptives. Furthermore, pills are a highly desired formulation approach and a weekly regimen instead of daily administration will likely contribute to a high acceptability and adherence among users. Based on promising early stage clinical data, we expect the use of weekly mifepristone 50 mg as a contraceptive will be safe, effective, and acceptable.

Being tested
Mifepristone 50 mg
Keywords
Oral, Weekly, Non-hormonal

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Mifepristone 50 mgDrug

    Once-weekly oral mifepristone 50 mg

Study groups in NCT06394999
Study groupRoleWhat they receive
mifepristone 50 mgExperimentalmifepristone 50 mg once weekly
Receives: Drug: Mifepristone 50 mg

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Overall Pearl Index

    Nominator Number of pregnancies with conception during treatment period from the first day of pill intake to the last day of pill intake + 7 days

    Denominator The time period from the first day of pill intake to the last day of pill intake + 7 days. Cycles with documentation of no unprotected intercourse will be subtracted from this period, unless in the unlikely case that a pregnancy occurred in such a cycle.

    Measured: 0-12 months

  2. Pearl Index by Method failure

    Nominator Number of pregnancies with conception during cycles as defined in the denominator

    Denominator The number of cycles with perfect use times 1300. A cycle is defined as (at least) 28 days after the first day of mifepristone 50 mg intake. Cycles with documentation of no unprotected intercourse will be subtracted from this time period, unless in the unlikely case that a pregnancy occurred in such a cycle. Also, cycles with non-perfect use, i.e. without mifepristone 50 mg intake at least once every 7 days will be excluded. Diary charts and counting of remaining tablets will provide dosing information to determine (non-) perfect use.

    Measured: 0-12 months

  3. Assess the contraceptive safety of once-weekly mifepristone 50 mg

    Proportion of women with endometrial thickness >15 mm, endometrium with irregular cystic appearance on US; with ALT, AST elevation three times above normal levels or bilirubin two times above normal levels; with adverse events / serious adverse events

    Measured: 3, 6 and 12 months

Secondary outcomes (9)

  1. Depression

    PHQ-9 questionnaire (mean value) and changes

    Measured: baseline, 3, 6 and 12 months

  2. Sexual functioning

    Female Sexual Function Index (FSFI) (mean value) and changes

    Measured: baseline, 3, 6 and 12 months

  3. Use of antidepressants

    Proportion of participants who use antidepressants or mood stabilizing drugs

    Measured: baseline, 3, 6 and 12 months

  4. Weight [kg]

    Weight changes

    Measured: baseline, 3, 6 and 12 months

  5. Bleeding profile

    Daily reported bleeding pattern and changes in bleeding pattern regarding amount of bleeding, pain, use of painkillers and effect on hemoglobin

    Measured: 0-365 days

  6. Side effects

    Proportion of participants with daily reported side-effects and changes

    Measured: 0-365 days

  7. Acceptability

    Proportion of participants who find the medication acceptable

    Measured: 3, 6 and 12 months

  8. Liver function

    Frequency of abnormal liver functions between 2 and 3 x ULN (ALT/AST) and time to become less than 2 x ULN

    Measured: 3, 6 and 12 months

  9. Pregnancy outcomes

    Number of abortions, miscarriages, ectopic pregnancies, preterm labor, growth restriction and congenital abnormalities

    Measured: 21 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted1 May 2024
  2. Study start2 May 2025
  3. Primary completion1 Jun 2027 (estimated)
  4. Study completion1 Jan 2028 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 3
Primary purpose
Prevention
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrolment
615 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT06394999
Sponsor's protocol ID
2022-502694-41-00
Acronym
WOMEN&More
Status last verified
Jun 2026
First submitted
29 Apr 2024
Last updated
8 Jun 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No

Questions about this trial

What is this clinical trial studying?

A Phase 3 study testing Mifepristone 50 mg in people with Female Contraception, run by Leiden University Medical Center at 14 sites in Netherlands.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 13 inclusion and 17 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: under way, not looking for participants, as of the sponsor's last update on 8 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 14 sites in Netherlands. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Overall Pearl Index (time frame: 0-12 months). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT06394999.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 8 Jun 2026.

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