Related tests: SHBG
Clinical significanceClinical indicationsSample typePreparation
Clinical significance
Testosterone can be derived from both pregnenolone and progesterone; both processes take place in the testicles, ovaries, adrenal glands and placenta, but the second takes place mainly in the gonads. Circulating testosterone is present both in free form and bound to SHBG (sex hormone-binding globulin) and shows a morning peak and a lower concentration (up to 25% lower) in the evening. Exercise raises testosterone, while immobilisation lowers it.
Clinical indications
In men, assessment of hormonal function; in women, hirsutism and polycystic ovary syndrome.
Sample type
The patient must have a blood sample taken.
Preparation
You must fast for at least 8 hours; a small amount of water is allowed.