Progesterone

Measures a reproductive hormone; interpretation depends on the cycle phase.

To assess ovulation and the luteal phase at the right time in the cycle.

1. Ask your doctor why progesterone is being ordered.
2. Plan for the appropriate cycle day and note the first day of your last period.
3. Tell staff if you take hormone preparations.
4. Have your blood drawn on the agreed day; if the timing changes, call ahead.

Fasting is often not necessary for this test alone. If other tests have also been ordered, or your doctor has prescribed specific preparation, follow the agreed rules.

To assess ovulation, blood is often drawn about 7 days before the expected period, not automatically on day 21 of the cycle.

• Cycle phase and day of ovulation
• Hormone preparations
• Pregnancy

Venous blood — serum or plasma, depending on the method

The blood sample is collected by a qualified staff member. The tube type, required volume, and processing and storage conditions are set by the laboratory's specific method. You do not need to store the sample yourself.

Progesterone levels change sharply with the cycle phase; a single value is informative for assessing ovulation only when drawn at the right time.

If you are pregnant or have severe abdominal pain, unusual bleeding or significant hormonal symptoms, see a gynecologist/endocrinologist; with emergency signs, seek care immediately.

To confirm ovulation, progesterone is usually measured about 7 days before the expected period, not on "day 21" for every patient.