ContraceptionPhase 4NCT05237141
Etonogestrel Implant as Emergency Contraception
A Phase 4 study testing Etonogestrel implant in people with Contraception, run by University of Colorado, Denver at 1 site in United States.
Trial summary
The investigators propose a single site, single arm, open label mechanism of action pharmacodynamic pilot study of etonogestrel implant insertion prior to an luteinizing hormone (LH) surge. Read more about this study
- Who is it for?
- Ages 18 to 40 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- Contraception
- What is being tested?
- Etonogestrel implant
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 12 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Apr 2022to Dec 2027
- Phase
- Phase 4
- 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 40 years
- Women only
- Healthy volunteers accepted
- Adult
Who may be able to join
- BMI less than or equal to 28kg/m2
- Intact uterus with at least one ovary
- Regular menstrual cycles that occur every 21-35 days
- If patient is postpartum or post-second trimester abortion, 3 menses (2 cycles) must have occurred prior to enrollment
- If patient had a first trimester abortion or pregnancy loss, she must have one spontaneous menses prior to enrollment
- Desires insertion of an etonogestrel contraceptive implant for contraception
- Not currently pregnant or trying to become pregnant
- Willing to abstain from medications and supplements known to induce/inhibit CYP3A4 during the study
Who cannot join
- Have a known hypersensitivity or contraindications to etonogestrel.
- Medical conditions that affect liver function (e.g., hepatitis, cirrhosis; assessed via participant self-report)
- Known or suspected current alcohol dependence syndrome or any illicit drug use that may affect the metabolism of the etonogestrel.
- Uncontrolled thyroid disorder.
- Use of long-acting injectable hormonal contraceptive within the past 9 months
- Current use of hormonal oral, patch, intravaginal, or intrauterine contraception
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
University of Colorado Denver
Aurora, Colorado, 80045
Eva Dindinger, BA, 303-724-8482, Eva.Dindinger@ucdenver.edu
MA
About this study
Official title: Etonogestrel Implant as Emergency Contraception: A Pilot Pharmacodynamic Study
The investigators propose a single site, single arm, open label mechanism of action pharmacodynamic pilot study of etonogestrel implant insertion prior to an luteinizing hormone (LH) surge. The investigators will evaluate ovulation rates via serum levels of reproductive hormones and transvaginal ultrasound findings following placement of an etonogestrel implant once the dominant follicle reaches a size of 15mm or greater, but prior to an LH surge, in persons with prior documented regular cycles and confirmed ovulation. The researchers' hypothesis is that ovulation will be inhibited if the etonogestrel implant is placed prior to an LH surge.
Based on data from the Food and Drug Administration label for Nexplanon, etonogestrel rises to levels associated with ovulation suppression within 8 hours of placement. Given this rapid increase, it is therefore plausible to assume that ovulation can be inhibited by the implant if placed prior to an LH surge. This study is novel as there have been no published studies evaluating an etonogestrel implant for this indication.
The contribution of this proposed research to the literature is significant because current recommendations from the Center for Disease Control (CDC) regarding timing of etonogestrel implant placement are stringent and not patient-centered. Any day insertion of the etonogestrel implant is supported by retrospective data and this pharmacodynamic data would further support the literature for any day insertion without the need for additional emergency contraception. If results support the investigators' hypothesis, it could increase access to contraception and decrease duplicative therapy.
- Conditions
- Contraception
- Being tested
- Etonogestrel implant
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Etonogestrel implantDrug
Implant insertion in second menstrual cycle prior to ovulation
| Study group | Role | What they receive |
|---|---|---|
| Main cohort | Experimental | Insertion of etonogestrel contraceptive implant prior to LH surge Receives: Drug: Etonogestrel implant |
What is being measured
The primary outcome is the main question the study is designed to answer.
Serum progesterone
Serial measurements of serum progesterone will be conducted after insertion of the etonogestrel implant to assess for evidence of potential ovulation (>3ng/mL)
Measured: 7 days
Ovarian follicle size
Serial transvaginal ultrasound measurements of the leading or dominant follicle will be conducted after insertion of the etonogestrel implant. Ovulation will be defined by follicle rupture with complete disappearance or at least a 50% reduction in the mean size of the leading follicle.
Measured: 7 days
Secondary outcomes (1)
Luteinizing hormone
Serial measurements of serum luteinizing hormone will be conducted after insertion of the etonogestrel implant. These LH concentrations will be used to support the primary outcomes in assessing ovulation.
Measured: 7 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted11 Feb 2022
- Study start1 Apr 2022
- Primary completionDec 2027 (estimated)
- Study completionDec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for ContraceptionStudies of the same condition, open and under way.
- More trials run by University of Colorado, DenverThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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 4
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 12 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Colorado, Denver
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05237141
- Sponsor's protocol ID
- 21-5026
- Status last verified
- Aug 2026
- First submitted
- 18 Jan 2022
- Last updated
- 11 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No: Will share summary data if requested
Publications
Cortez A, Belmonte MA, Lazorwitz A, Fang NZ. Etonogestrel contraceptive implant as emergency contraception: a mechanism of action pharmacodynamic pilot study. Contraception. 2026 Sep 16:111725. doi: 10.1016/j.contraception.2026.111725. Online ahead of print.
PubMed 42749037
Study at a glance
From the registry record, last updated by the sponsor on 11 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Etonogestrel Implant as Emergency Contraception: A Pilot Pharmacodynamic Study
- ClinicalTrials.gov ID
- NCT05237141
- Acronym / sponsor ID
- 21-5026
- Conditions
- Contraception
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 12 participants (estimated)
- Lead sponsor
- University of Colorado, DenverUniversity, hospital or other
- Study start
- 1 Apr 2022 (actual)
- Primary completion
- Dec 2027 (estimated)
- Study completion
- Dec 2027 (estimated)
- First posted
- 11 Feb 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The investigators propose a single site, single arm, open label mechanism of action pharmacodynamic pilot study of etonogestrel implant insertion prior to an luteinizing hormone (LH) surge. The investigators will evaluate ovulation rates via serum levels of reproductive hormones and transvaginal ultrasound findings following placement of an etonogestrel implant once the dominant follicle reaches a size of 15mm or greater, but prior to an LH surge, in persons with prior documented regular cycles and confirmed ovulation. The researchers' hypothesis is that ovulation will be inhibited if the etonogestrel implant is placed prior to an LH surge.
Based on data from the Food and Drug Administration label for Nexplanon, etonogestrel rises to levels associated with ovulation suppression within 8 hours of placement. Given this rapid increase, it is therefore plausible to assume that ovulation can be inhibited by the implant if placed prior to an LH surge. This study is novel as there have been no published studies evaluating an etonogestrel implant for this indication.
The contribution of this proposed research to the literature is significant because current recommendations from the Center for Disease Control (CDC) regarding timing of etonogestrel implant placement are stringent and not patient-centered. Any day insertion of the etonogestrel implant is supported by retrospective data and this pharmacodynamic data would further support the literature for any day insertion without the need for additional emergency contraception. If results support the investigators' hypothesis, it could increase access to contraception and decrease duplicative therapy.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Main cohort | Experimental | Drug: Etonogestrel implantInsertion of etonogestrel contraceptive implant prior to LH surge |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (8 listed)
- BMI less than or equal to 28kg/m2
- Intact uterus with at least one ovary
- Regular menstrual cycles that occur every 21-35 days
- If patient is postpartum or post-second trimester abortion, 3 menses (2 cycles) must have occurred prior to enrollment
- If patient had a first trimester abortion or pregnancy loss, she must have one spontaneous menses prior to enrollment
Key exclusion criteria (6 listed)
- Have a known hypersensitivity or contraindications to etonogestrel.
- Medical conditions that affect liver function (e.g., hepatitis, cirrhosis; assessed via participant self-report)
- Known or suspected current alcohol dependence syndrome or any illicit drug use that may affect the metabolism of the etonogestrel.
- Uncontrolled thyroid disorder.
- Use of long-acting injectable hormonal contraceptive within the past 9 months
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Etonogestrel implantImplant insertion in second menstrual cycle prior to ovulation | Drug | Main cohort |
Primary outcome
Serum progesterone
Time frame: 7 days
Serial measurements of serum progesterone will be conducted after insertion of the etonogestrel implant to assess for evidence of potential ovulation (>3ng/mL)
Ovarian follicle size
Time frame: 7 days
Serial transvaginal ultrasound measurements of the leading or dominant follicle will be conducted after insertion of the etonogestrel implant. Ovulation will be defined by follicle rupture with complete disappearance or at least a 50% reduction in the mean size of the leading follicle.
1 secondary outcome
Luteinizing hormone
Time frame: 7 days
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Aug 2026.
- Derived from this study: PubMed 42749037Cortez A, Belmonte MA, Lazorwitz A, Fang NZ. Etonogestrel contraceptive implant as emergency contraception: a mechanism of action pharmacodynamic pilot study. Contraception. 2026 Sep 16:111725. doi: 10.1016/j.contraception.2026.111725. Online ahead of print.
- Individual participant dataSharing planned: No. Will share summary data if requested
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Etonogestrel implant in people with Contraception, run by University of Colorado, Denver at 1 site in United States.
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 8 inclusion and 6 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: looking for participants now, as of the sponsor's last update on 11 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. 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 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
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?
Contact Emily Graves, BS (303-724-3514, emily.graves@cuanschutz.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Serum progesterone (time frame: 7 days). The study lists 2 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 NCT05237141, which also lists 1 linked publication.
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 11 Aug 2026; AzTrials last refreshed its copy on 6 Nov 2026.