A hormone that promotes the development and maintenance of male sex characteristics.


... Why get tested?
To determine if your testosterone level is abnormal, which may help to explain difficulty getting an erection (erectile dysfunction), inability of your partner to get pregnant (infertility), or premature or delayed puberty if you are male, or the appearance of masculine physical features if you are female

When to get tested?
If you are male and your doctor thinks that you may be infertile or if you are unable to get or maintain an erection; if you are a boy with either early or delayed sexual maturity; if you are a female but have male traits, such as a low voice or excessive body hair, or are infertile

Sample required?
A blood sample drawn from a vein in your arm
Lab Tests Online - more...

For the website/magazine of the same name see T-Nation Testosterone ...
Wikipedia - [full article]