The goal of this clinical trial is to evaluate how differences in specific parts of our DNA can influence how individual bodies break down the hormones contained within oral contraceptive pills, which could affect how well these birth control pills work to prevent pregnancy. The investigators are also interested in exploring how these differences in our DNA can also explain why patients taking the exact same formulation of birth control pill will experience very different side effects. The main questions it aims to answer are:
* Do individuals with the CYP3A7\*1C variant have increased metabolism of both desogestrel and ethinyl estradiol when taking a combined oral contraceptive pill?
* Do individuals with the CYP3A7\*1C variant experience higher rates of breakthrough ovulation while taking a desogestrel/ethinyl estradiol combined oral contraceptive pill?
* What novel genetic loci are associated with alterations in steroid hormone pharmacokinetics and pharmacodynamics among a larger cohort of combined oral contraceptive pill users?
Participants will take a specific formulation of combined oral contraceptive pill (desogestrel/ethinyl estradiol) and undergo the following procedures:
* Blood draw to measure the amount of progestin and estrogen in their system from the combined oral contraceptive pill
* Questionnaires to assess side effects possibly caused by the combined oral contraceptive pill
* Blood draw to measure endogenous hormone levels and biomarkers that may be affected by the combined oral contraceptive pill
* A transvaginal ultrasound to measure any ovarian follicles (optional procedure)
Who can participate
Age range
18 Years – 45 Years
Sex
FEMALE
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion criteria
. Provision of signed and dated informed consent form
. Stated willingness to comply with all study procedures and availability for the duration of the study
. Female, aged 18-45 years old
. In good general health as evidenced by medical history and no need for regular intensive medical interventions (e.g., inpatient admissions, surgical treatments). The Principal Investigator will be responsible for determining good general health for potential participants with complicated medical histories.
. Ability to take oral medication and be willing to adhere to the oral contraceptive pill (DSG/EE) regimen
. Body-mass index ≥18.5kg/m2
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Serum etonogestrel concentration
Timeframe: Measured as a trough concentration on Cycle 1, Day 22 (each cycle is 28 days)
2
Serum ethinyl estradiol concentration
Timeframe: Measured as a trough concentration on Cycle 1, Day 22 (each cycle is 28 days)
. Willing to abstain from medications and supplements known to induce/inhibit CYP3A (e.g., rifampin, carbamazepine, ketoconazole, St. John's wort) during the study
. Normal blood pressure measurement at study screening
Exclusion criteria
. Currently taking any known CYP3A inducers/inhibitors (e.g., rifampin, carbamazepine, ketoconazole, St. John's wort)43
. Any medical conditions that affect liver function (e.g., hepatitis, cirrhosis)
. Contraindications to estrogen-containing contraception (based on category 3 or 4 recommendations in the CDC MEC guidelines42)
. Current breast cancer or personal history of breast cancer
. Severe decompensated cirrhosis
. Personal history of deep venous thrombosis or pulmonary embolism
. Recent major surgery with prolonged immobilization
. Diabetes with nephropathy, retinopathy, neuropathy, or other vascular disease