The Effect of Isotretinoin on the Etonogestrel Contraceptive Implant

The Investigators will enroll only women with an etonogestrel contraceptive implant in place
who are initiating isotretinoin therapy through their dermatologist. The Investigators will
monitor the subjects serum etonogestrel concentration during isotretinoin therapy but no
medications will be provided through this study. No medical devices will be inserted as part
of this study either.

Inclusion Criteria:

- Have a secondary form of non-hormonal contraception or abstain during isotretinoin
therapy and four weeks afterwards

- Have at least two negative pregnancy tests at least 19 days apart prior to initiating
isotretinoin therapy

- Have normal baseline laboratory evaluation including liver function tests, basic
metabolic panel, and complete blood count

- Willing to abstain from taking any Vitamin A supplement during the study period

- Have a Body Mass Index (BMI) >= 18.5

Exclusion Criteria:

- Currently breastfeeding

- Known contraindications to isotretinoin

- Currently taking any known cytochrome P-450 3A4 enzyme inducers or inhibitors