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What the hypothesis claims

The popular story says: under stress the adrenals “steal” pregnenolone to make cortisol, leaving too little substrate for DHEA and the downstream sex hormones. It’s tidy—and wrong.

How adrenal steroid production actually works

1) Three independent factory floors.
The adrenal cortex has three zones with different enzyme toolkits and separate regulation:

• Zona glomerulosa → aldosterone (no CYP17A1).
  

• Zona fasciculata → cortisol (17-hydroxylase present; not the lyase configuration for androgens).
  

• Zona reticularis → DHEA/androgens (17-hydroxylase and 17,20-lyase activity with cytochrome b5).
  Because each zone expresses a distinct enzyme set, they do not share one common product stream that can be “reallocated” at will. (NCBI, PMC)

2) Made on-site, not from a shared pool.
Every steroidogenic cell pulls cholesterol into its own mitochondria (via StAR) and converts it to pregnenolone inside that cell. There isn’t a gland-wide pregnenolone reservoir for one zone to “steal” from another. (ZRT Lab)

3) Regulation is by signalling, not substrate tug-of-war.

• Cortisol output is driven mainly by ACTH from the pituitary (HPA axis).
  

• Aldosterone is driven primarily by RAAS (angiotensin II, potassium).
  

• Adrenal androgens (DHEA) respond to ACTH and intra-adrenal enzyme regulation (e.g., 17,20-lyase co-factors).
  These systems alter enzyme activity and cholesterol delivery, not a communal pregnenolone tank. (NCBI, endotext.org)
  

Cortisol molecule by Ben Mills - Own work, Public Domain, link

What stress really does to sex-hormone output

Stress alters hormones largely from the top down:

• CRH and cortisol blunt the HPG axis, reducing GnRH pulse frequency and downstream LH/FSH. That lowers ovarian/testicular stimulation and can reduce estradiol, progesterone and testosterone production without any “steal.” (PMC)

(If you want a one-liner to keep: “Stress can reduce sex-hormone output via brain-level regulation—CRH/cortisol suppress GnRH pulses—rather than by ‘stealing’ pregnenolone.”)

Why the “steal” model fails (biologically)

• No pool to steal from. Pregnenolone is made where it’s used - inside each cell’s mitochondria. (ZRT Lab)
  

• Different zones, different enzymes. Glomerulosa can’t make cortisol or DHEA; reticularis can’t make aldosterone; fasciculata is optimised for cortisol. There’s no single tap to divert. (NCBI, PMC)
  

• Observed stress effects fit central control. Animal and human data show sustained cortisol/CRH signalling suppresses the GnRH/LH pulse generator, explaining lower gonadal output without invoking substrate competition. (PMC)
  

Three accessible expert resources that explicitly debunk “pregnenolone/cortisol steal”

• ZRT Laboratory (Thomas Guilliams, PhD) — Re-assessing the Notion of “Pregnenolone Steal” (clear explanation that there is no known adrenal pregnenolone pool or mechanism for inter-cell “steal”). (ZRT Lab)
  

• DUTCH (Educational slide deck) — Reset Your Stress Response (states plainly: “Pregnenolone steal is not real,” and reframes issues as brain-to-adrenal signalling/HPA-axis dysfunction). (Dutch Test)
  

• Kresser Institute interview with Thomas Guilliams, PhD — discusses why the pool-diversion picture is misleading and how the adrenals actually decide outputs. (Kresser Institute Membership Site)

(All three mention “pregnenolone steal” by name and explain why it’s incorrect.)

How the myth likely took hold and persisted 

1. 1990s–2000s alternative-medicine/adrenal-fatigue literature.
   The term “adrenal fatigue” was popularised by James L. Wilson (1998). Within that ecosystem, the linear “steroid pathway” graphic was over-interpreted as a zero-sum game (the seedbed for “steal”). (Wikipedia)
   

2. Seminar/blog circuits in functional medicine.
   High-traffic sites/books (e.g., Datis Kharrazian’s materials) used and taught “pregnenolone steal” to explain PMS/perimenopause symptoms, propagating the story widely online. (Dr. K. News)
   

3. Early lab education/marketing around salivary cortisol/DHEA.
   Some practitioner slide decks historically framed low DHEA as a marker of “pregnenolone steal,” citing Wilson; these materials circulated for years in training. (gdx.net)

Note: Even organisations once adjacent to the narrative (e.g., ZRT) have since published explicit corrections debunking it. (ZRT Lab)

Has the misinformation led to harm?

Potentially, yes—mainly via misdiagnosis and inappropriate treatment:

• Missed real diagnoses. Major endocrine societies warn that chasing “adrenal fatigue/steal” risks overlooking treatable causes of fatigue, anxiety, insomnia, anaemia, thyroid disease, depression, or true adrenal disorders. (Endocrine)
  

• Unnecessary steroid precursors. People are sometimes given DHEA or pregnenolone “to refill the pathway.” Evidence for broad benefit is weak, while androgenic side-effects (acne, hirsutism) and mood effects are documented. (Mayo Clinic, PMC)
  

• Cost and false reassurance. The Endocrine Society notes “adrenal fatigue” treatments are not FDA-approved and can be expensive, diverting people from appropriate care. (Endocrine)
  

The accurate replacement model 

• Stress → HPA axis signalling (CRH/ACTH) tunes adrenal enzyme activity and cholesterol transport within each zone.
  

• Stress → HPG axis suppression (reduced GnRH/LH/FSH pulsatility) lowers gonadal steroid output (estradiol, progesterone, testosterone).
  

• Net effect: you can see lower sex-hormone production under stress, but via regulation, not “steal.” (PMC, NCBI)

Verify before you amplify - 

Please fact check this information using the following prompt on chat GPT:

“Can you explain clearly why the cortisol (pregnenolone) steal hypothesis is incorrect? Please give me a structured answer with headings, explain how adrenal steroid production really works, and include three accessible research or expert links that specifically debunk the cortisol/pregnenolone steal idea. Please give me a list of three possible people/places by which this myth was created and subsequently allowed to perpetuate for so long. And out of curiosity has the misinformation potentially led to harm via inappropriate treatments?”

Here is a public link to the output. If yours is very different to ours we’d love to hear about it.

https://chatgpt.com/share/68adbeea-94e0-8002-9b96-a62e0d88a2e1

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