Women currently using or starting a combined oral contraceptive will be offered study enrollment. Study subjects will have a Nexplanon placed and followed for 6 months to evaluate if they continue the COC, continue the implant, or both, and to assess adverse events and bleeding patterns.

The investigators will recruit women being seen in a UC Davis medical office or who contact our research office. Potential participants must be women currently COCs or intending to initiate COCs at the time of the office visit. The investigators expect that most women will be recruited while in the office who decide to initiate COCs or are continuing COC use-these women will be offered the ability to talk to research staff about the study.

Visit 1:

Informed consent will be obtained. As part of informed consent, subjects will be educated that there is little data available on the adverse effects of combined COC and ENG implant use. The consent form will include a standardized description of the side effects and bleeding profile of COCs and the implant. Subjects will also need to review the package label information for Nexplanon and sign the FDA-required Nexplanon consent. After obtaining informed consent, subjects will be screened for entry criteria. Medical history will be obtained. A urine pregnancy test will be performed. Eligible subjects will receive a prescription for the desired COC (if needed) and have a Nexplanon contraceptive implant placed. A diary will be dispensed for the subject to document daily bleeding, COC use and adverse events.

Follow-up A follow-up visit will occur at 1 month (+1 week) and 3 and 6 months (+2 weeks). The diary will be reviewed and a copy made to keep with the source documentation. Adverse events will be determined by inquiry and diary review. The subject will inform the study staff if she is using her COC and if she wants to continue use of her COC and ENG implant. At the 1 and 3 month visits, additional diaries will be dispensed as needed. The ENG implant will be removed upon request at any time during the study.

A phone call will occur approximately 1 week prior to the 3 and 6 month visits to check status and remind subject of the scheduled visit. Study participation will be complete after the 6 month follow-up visit.

No surveys will be used that the subject fills out herself. A daily diary will be used.

No blood draws will occur during this study.

Data to be collected by study staff include demographics, past medical and gynecologic history, prior and current contraceptive use, and reason for using COC (contraception, medical or both).

Because women are being enrolled who are already currently using COCs or who plan to start COCs, the COC is not a study drug. The study intervention (study drug) is the contraceptive implant. The systemic hormone exposure with a contraceptive implant is minimal relative to a COC. We would not expect any increase in side effects by adding a contraceptive implant to COC users. Of note, the primary risk with COC use is related to the estrogen which can increase the risk of venous thromboembolic disease. The implant has no estrogen. All products being used in the study are FDA-approved for contraception.

Inclusion:

• Women being seen in a UC Davis medical office or who contact our research office.
• Potential participants must be women currently COCs or intending to initiate COCs at the time of the office visit.

Exclusion:

• Women who have contraindications to using a COC or a contraceptive implant (Category 3 or 4 in the CDC Medical Eligibility Criteria) will be excluded.
• Adults unable to consent
• Individuals who are not yet adults (infants, children, teenagers)
• Pregnant women
• Prisoners

6 months of follow-up