P4 (Progesterone) & E2 (Oestrogen)

This test measures two key reproductive hormones, progesterone (P4) and oestrogen (E2), to provide a clear picture of your ovulatory function and hormonal balance. It is suitable for anyone investigating fertility, irregular cycles, or symptoms of hormonal imbalance, and can be used to confirm ovulation, assess ovarian reserve, or monitor response to fertility treatment.

Progesterone (P4)
- Produced mainly after ovulation by the corpus luteum, progesterone prepares the womb lining for implantation and supports early pregnancy.
- A single measurement, timed about 7 days before your expected period (day 21 of a 28-day cycle), helps confirm whether ovulation has occurred.
- Low levels may indicate anovulation, luteal phase defect, or problems with the corpus luteum.

Oestrogen (E2)
- Oestradiol is the most potent form of oestrogen and is produced by developing ovarian follicles.
- It drives the growth of the uterine lining in the first half of the cycle and triggers the surge in luteinising hormone (LH) that leads to ovulation.
- Levels are used to assess ovarian reserve, monitor follicle development during IVF, and investigate causes of irregular or absent periods.

Why it matters
Understanding your progesterone and oestrogen levels gives you and your clinician essential information about your ovulatory status and ovarian function. This can guide decisions about fertility treatment, help identify the cause of cycle problems, and provide reassurance or direction when you are trying to conceive. All results are interpreted alongside your cycle history and other clinical findings by your doctor.