What is the Origin of Progesterone Steal?

The term originated within the functional and integrative medicine communities, based on the anatomical arrangement of the steroidogenesis cascade, which details the biochemical conversion of cholesterol into various steroid hormones. The model highlights the competitive nature of enzyme utilization in this pathway, particularly under the sustained demand of the HPA axis.

What is the Mechanism of Progesterone Steal?

The hypothetical mechanism is centered on the enzyme 3-beta-hydroxysteroid dehydrogenase/isomerase, which converts pregnenolone to progesterone, and the enzyme 17-alpha-hydroxylase, which directs pregnenolone toward cortisol synthesis. Under chronic stress, the HPA axis demands high cortisol output, theoretically upregulating the cortisol pathway enzymes. This increased demand for precursors supposedly "steals" pregnenolone that would otherwise be available for progesterone production, thus creating a functional deficiency in the face of persistent psychological or physiological stress.

Progesterone Steal ∞ Area

Progesterone Steal

Meaning

Progesterone Steal is a conceptual model, rather than a proven physiological mechanism, suggesting that chronic, unmanaged stress preferentially shunts the common precursor molecule pregnenolone away from the production of progesterone and toward the synthesis of the stress hormone cortisol. This proposed diversion of the steroidogenesis pathway is theorized to lead to a relative progesterone deficiency, contributing to symptoms like estrogen dominance, anxiety, and sleep disturbances. While clinically utilized, this model remains a topic of scientific debate within mainstream endocrinology.