Long-term testing of an etonogestrel implant placed over the shoulder blade

Prospective Long-term Study of Etonogestrel Contraceptive Implant Insertion at an Alternative Scapular Site

This project will test whether placing the etonogestrel contraceptive implant over the shoulder blade gives steady drug levels and acceptable side effects for people assigned female at birth aged 18 to 45.

Quick facts

• Phase: PHASE2
• Study type: Interventional
• Enrollment: 62 (estimated)
• Ages: 18 Years to 45 Years
• Sex: Female
• Sponsor: Yale University (other)
• Locations: 2 sites (Aurora, Colorado and 1 other locations)
• Trial ID: NCT07201402 on ClinicalTrials.gov

What this trial studies

This Phase 2 interventional protocol examines long-term outcomes after inserting the etonogestrel contraceptive implant at an alternative scapular (shoulder blade) site instead of the usual upper arm location. Participants assigned female at birth aged 18–45 who choose an implant will have it placed over the scapula and return for scheduled visits over at least two years to measure blood drug concentrations and record side effects and local reactions. The study includes serial pharmacokinetic sampling and standardized safety assessments, and requires participants to avoid medications or supplements that strongly affect CYP3A metabolism. The trial is led by Yale University with a collaborating site at the University of Colorado Anschutz and support from NICHD.

Who should consider this trial

Good fit: Ideal candidates are people assigned female at birth aged 18–45 in good general health who want an etonogestrel implant, are not pregnant, and can avoid medications that alter CYP3A metabolism during the study.

Not a fit: People who are pregnant, outside the 18–45 age range, unable to avoid CYP3A-inducing or -inhibiting medications, or who have medical contraindications to progestin implants are unlikely to benefit.

Why it matters

Potential benefit: If successful, this could provide an alternative insertion site that maintains contraceptive drug levels while offering improved comfort, concealment, or accessibility for some users.

How similar studies have performed: Using non-arm insertion sites for etonogestrel implants is relatively novel and has limited published long-term data, so this specific approach remains largely untested.

Eligibility criteria

Inclusion Criteria:

1. Provision of signed and dated informed consent form
2. Stated willingness to comply with all study procedures and availability for the duration of the study
3. Sex assigned at birth must be Female
4. Aged 18-45 years
5. 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
6. Interest and willingness to use an etonogestrel contraceptive implant
7. Negative pregnancy test at the time of study enrollment and not planning to become pregnant in the next 36 months
8. Willing to abstain from medications and supplements known to induce/inhibit CYP3A (e.g., rifampin, carbamazepine, ketoconazole, St. John's wort) during the study. In the inducer/inhibitor CYP3A medication is a prescribed medication, individuals must provide the prescriber information for the PI to confirm it is safe for this medication to be abstained during the study
9. Body-mass index ≥18.5kg/m2

Exclusion Criteria:

1. Self-reported contraindications to the use of the ENG implant based on the CDC Medical Eligibility Criteria guidelines for any conditions with a category 3 or 4 recommendation

   1. Current breast cancer or personal history of breast cancer
   2. Malignant liver tumor (hepatocellular carcinoma)
   3. Allergic reaction to any components of the ENG implant
2. Any self-reported known liver conditions that could affect drug metabolism (e.g., cirrhosis, hepatitis)
3. Personal history of deep vein thrombosis (DVT), venous thromboembolism (VTE), or arterial thromboembolism (ATE).
4. Currently taking and unable or unwilling to abstain from any medications or supplements known to be CYP3A inducers/inhibitors.
5. Current use of a progestin-only contraceptive method containing desogestrel or etonogestrel
6. History of spinal deformity (e.g., kyphosis, lordosis)
7. History of shoulder or scapular surgery on the non-dominant side
8. Non-dominant shoulder mobility limitations
9. Previous trauma to the non-dominant scapular region
10. Active skin conditions (e.g., psoriasis) in the non-dominant scapular region
11. Inability to palpate the bony landmarks of the scapula due to adiposity or other body habitus

Where this trial is running

Aurora, Colorado and 1 other locations

• University of Colorado Anschutz Medical Campus — Aurora, Colorado, United States (NOT_YET_RECRUITING)
• Yale University School of Medicine — New Haven, Connecticut, United States (RECRUITING)

Study contacts

• Principal investigator: Aaron Lazorwitz, MD — Yale University
• Study coordinator: Professional Research Assistant

Conditions: Contraception, contraceptive implant, scapular insertion site, etonogestrel