Pregnenolone
What it measures, and what changes the number.
Pregnenolone is a steroid hormone made from cholesterol, mainly in the adrenal glands and gonads. It sits at the start of the steroid production pathway and is the building block for cortisol, DHEA, progesterone and the sex hormones. The test measures its level in blood.
It is usually ordered with other steps of the same pathway, such as 17-OH pregnenolone, DHEA, DHEA-S, progesterone and 17-OH progesterone, so the pattern along the chain can be compared. Cortisol and ACTH may be added for adrenal context.
Levels follow a daily rhythm, so labs often ask for a morning sample. The method matters: labels such as PREGNENOLONE, LC/MS indicate mass spectrometry, which tends to be more specific than immunoassays, so results from different methods are not directly comparable. It may also appear as Pregnenolona.
Often read alongside: 17-OH pregnenolone, DHEA, DHEA-S, Progesterone, 17-OH progesterone