Recruiting

Emergency Contraceptive

Sponsor:

Oregon Health and Science University

Code:

NCT05674513

Conditions

Contraceptive Usage

Eligibility Criteria

Sex: Female

Age: 18 - 40

Healthy Volunteers: Accepted

Interventions

Ulipristal acetate

Study Details

Brief summary:

The purpose of this study is to learn more about why some people are at greater risk for oral emergency contraceptive failure while others are not. The investigators want to learn if genetic differences impact the risk of emergency contraception failure.

Conditions

Contraceptive Usage

Study ID

NCT05674513

Start date

Jan 9, 2023

Status verified date

Jul, 2026

Completion date

Dec 31, 2027

Anticipated

Primary completion date

Dec 31, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: Female

Age: 18 - 40

Healthy Volunteers: Accepted

Inclusion Criteria:

  • Generally healthy women
  • Aged 18-40
  • regular menses (every 21-35 days) experiencing ovulatory cycles proven by a single progesterone level of 3 ng/mL or greater during the luteal phase of the screening cycle.

Exclusion Criteria:

  • Pregnant, seeking pregnancy, or breastfeeding
  • Known allergy to study medication
  • Recent use of hormonal contraception
  • Irregular periods (<21 days or >35 day cycles)
  • Routine use of nonsteroidal anti-inflammatory drugs
  • Metabolic disorders
  • Smoking
  • Any condition that would preclude the provision of informed consent
  • Using drugs (within 2 weeks of study enrollment) known to interfere with the metabolism of UPA as well as drugs known to be CYP3A4 inducers, inhibitors, or CYP3A drug substrates

Study Design

Enrollment

140 participants

Anticipated

Allocation

Non randomized

Intervention Model

Single group

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

active comparator: Active CYP3A5 Allele

Ulipristal acetate 30mg orally x 1 dose with pharmacokinetic and pharmacodynamics testing in individuals with active CYP3A5 alleles

active comparator: Inactive CYP3A5 Allele

Ulipristal acetate 30mg orally x 1 dose with pharmacokinetic and pharmacodynamics testing in individuals without active CYP3A5 alleles

Interventions

Ulipristal acetate

Evaluating the pharmacodynamic and pharmacokinetic outcomes after 1 dose of Ulipristal acetate 30mg in individuals with and without active CYP3A5 alleles

Primary outcome measure

  • Delay in follicular rupture [ Time Frame: over 1 menstrual cycle (assessed up to approximately 30 days) ]
  • Concentration of UPA [ Time Frame: 5 days after taking study drug ]

Central Contacts and Locations

Central contacts

Women's Health Research Unit Department of OB/GYN

503-494-3666whru@ohsu.edu

Locations

OHSU

Recruiting

Portland, Oregon, United States, 97239

More Information

Sponsor

Oregon Health and Science University

Last update posted

Jul 9, 2026

Last verified

Jul, 2026

Keywords

  • Ulipristal acetate
  • Emergency contraception

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Oregon Health and Science University on 2026-07-09.