Testosterone
Also written: T
What it measures
Testosterone in blood, total and sometimes free.
Why it is ordered
Ordered with persistent fatigue, reduced libido, or while investigating fertility.
How to prepare
Usually drawn early morning because levels vary through the day. Ask whether fasting is needed.
Units
ng/dL ↔ nmol/L — convert here
What to ask
- At what time should it be drawn
- Is a repeat needed to confirm
- What does this change in my plan
This page does not include reference ranges and does not say whether your number is high or low. Reference ranges differ between laboratories and between people — read yours on your own report, with your clinician.