Key findings:

✅ 46% of individuals achieved serum estradiol within the target range of Australian guidelines.

✅ Median serum estradiol was 396 pmol/L on 1.5 mg (2 pumps) daily.

EstroGel represents a safe alternative first-line option for gender-affirming hormone therapy.

We suggest that treating clinicians should provide this information by using the corresponding gender marker on laboratory requests or provide relevant history to ensure the appropriate laboratory reference ranges are reported.

Once individuals have commenced GAHT, in general, the reference range of the affirmed gender should be reported for laboratory tests with sex-specific reference intervals (including haemoglobin/haematocrit and creatinine).

With increasing numbers of trans people seeking gender affirming hormone therapy (GAHT), it is important that clinicians, pathologists, and laboratory scientists use appropriate reference ranges.