Androstenedione
What it measures, and what changes the number.
Androstenedione is a steroid hormone made by the adrenal glands and by the ovaries or testes. It sits partway along the pathway that produces testosterone and estrone, and the test measures its concentration in serum.
It is often ordered with DHEA-S, total testosterone and 17-OH progesterone to help show which gland and which step of steroid production a result relates to, and sometimes with cortisol or estrone.
Levels follow a daily rhythm and are usually highest in the morning, so samples are commonly drawn early in the day; in people who menstruate, the cycle phase can also matter. Immunoassays can cross react with similar steroids, and mass spectrometry methods may give different results, so the method matters when comparing reports. Labs may print it as ANDROSTENEDIONE.
Often read alongside: DHEA-S, Total testosterone, 17-OH progesterone, Cortisol, Estrone (E1)