During puberty, hormones like luteinizing hormone (LH) help girls' bodies change into adulthood. This study looks at how another hormone called progesterone affects the timing of LH. Doctors want to see if giving girls small doses of progesterone stops LH from rising at night. They also want to check if too much testosterone in the blood affects this process.

Girls who join this study will visit a hospital for tests. They will get small amounts of progesterone and have their blood drawn to check hormone levels. The study lasts for one day, but there are follow-ups for up to three years to see how puberty progresses.

• Study visits and follow-ups are required, which may include overnight stays.
• Participants will take small doses of progesterone during the study.
• Blood tests will be done frequently to monitor hormone levels.