Accessibility links
|
|
Free Testosterone
(a.k.a FTE)
minimum sample volume required ~ 5ml
Tube type: SST
Other acceptable tube types
Lithium heparin (pale green)
Reference range
≥18 years old: 0.17 – 0.66
Units
nmol/L
Linked to
Testosterone, SHBG, albumin
Turnaround Time
1
day
Department: Biochemistry
Clinical Application
Free testosterone is a calculated test using testosterone, SHBG and albumin.
It can be calculated as part of the investigation of male hypogonadism where total testosterone is low, to determine whether free (bioavailable) testosterone is also low.
An FTE calculation will be added (where clinically indicated) by the Duty Biochemist where total testosterone is 5.5 – 9.9 nmol/L and the patient is not on anti-androgen treatment.
Where initial testosterone and FTE are low, suggest repeat testosterone measurement and free testosterone calculation on a 9am, fasting sample. If the repeat testosterone and calculated free testosterone remain low, the Duty Biochemist may add additional hormone tests (such as LH and FSH) to determine whether this is likely to represent a primary or secondary (hypogonadotrophic hypogonadism) hypogonadism.
Webpage created: September 2025.
