This test is available for people with female biology. Follow the separate sample-timing guidance shown for the test or panel you have selected.
Progesterone
Progesterone testing is cycle-dependent and should be appropriately timed.
For patients with regular cycles, testing should generally be performed approximately 7 days before the expected next period. A fixed day-21 test is only appropriate for a typical 28-day cycle.
For patients with irregular cycles, progesterone should ideally be measured approximately 7 days after confirmed or suspected ovulation, where ovulation can be reliably identified.
Patients taking HRT, progesterone, progestogens or hormonal contraception should disclose their treatment, as exogenous hormones can significantly affect progesterone results and their interpretation.
Progesterone testing should not be used to assess ovulation without considering the timing of the sample in relation to the menstrual cycle and any hormonal treatment.