You’ve been told your hormones are normal. You’ve been under pressure for years: work, family, broken sleep. Your libido has gone, your periods have changed, and you’re tired in a way that rest doesn’t touch. The link between long-running stress and those symptoms is real. The question is how it works, because the mechanism decides what you look for.
What the theory says
The pregnenolone steal goes like this. Pregnenolone, made from cholesterol, is the starting material for every steroid hormone: cortisol, DHEA, progesterone, testosterone, oestrogen. Under chronic stress, the theory says, the body diverts a shared pool of pregnenolone into cortisol, and the sex hormones are starved of raw material. Fix the stress and the raw material flows back.
It is a tidy picture, and it is widely taught in functional medicine. I taught it here.
Why it doesn’t fit how hormones are made
The problem is that there is no shared pool. Each steroid-making cell makes its own pregnenolone from cholesterol, inside its own mitochondria, and uses it there. The hormones are made in different places:
Cortisol made in one layer of the adrenal gland cannot take raw material from the ovaries, and the layers that make cortisol and DHEA have different regulators (Endotext, Adrenal Androgens). The tissue-by-tissue map of steroid production is standard endocrinology.
Grade: strong that steroid hormones are made in separate tissues from locally made pregnenolone. Grade: none for a shared pregnenolone pool that cortisol drains.
What stress actually does
Stress does lower sex hormones. It does it through signalling, not by stealing ingredients. The stress system and the reproductive system are both run from the brain. When the stress system is busy, stress hormones turn down the pulses of GnRH from the hypothalamus, which lowers LH and FSH from the pituitary, which are the signals that tell the ovaries and testes to work (Whirledge & Cidlowski 2013). In women the clearest result is fewer ovulations, and no ovulation means no corpus luteum and little progesterone that cycle.
At its extreme this is a recognised diagnosis, functional hypothalamic amenorrhoea: periods stop, with no disease to explain it, usually in the setting of stress, weight loss, heavy exercise or a combination (Endocrine Society guideline, Gordon 2017). Most people under chronic stress sit somewhere short of that: cycles that are irregular, shorter luteal phases, lower progesterone, a flatter libido.
DHEA is a separate story. It falls steadily with age from the mid-twenties, and lower levels are seen in some people under long-term stress or illness. Cortisol and DHEA can move in opposite directions, which is worth seeing on a test. It isn’t evidence of a steal.
Grade: strong that stress suppresses the reproductive axis through the brain (consistent animal and human evidence, and a recognised clinical diagnosis at the extreme). Grade: mixed for how much ordinary day-to-day stress lowers sex hormones in a given person.
Why the mechanism matters
Both explanations agree on one thing: if stress is driving the problem, the stress load is the first target. Where they differ is in what else you look for.
The steal model points only at cortisol. The signalling model points at everything that tells the brain it isn’t a safe time to reproduce. That includes eating too little for the training you do, losing weight, poor sleep, illness and inflammation, as well as psychological stress. It also means checking the things that suppress ovulation for other reasons: thyroid, prolactin, polycystic ovaries and perimenopause.
It changes one more claim. You will read that progesterone taken as a supplement gets “converted to cortisol” while the steal continues. There is no good evidence for that, and this page used to say it. Whether hormone treatment is right for you is a decision for you and your doctor, made on its own evidence.
What a DUTCH test can and can’t show
The DUTCH Plus shows the cortisol pattern across the collection day, the cortisol awakening response from saliva, DHEA and its metabolites, progesterone metabolites, androgens and oestrogens. Collected on the right day of the cycle, it shows whether progesterone looks like a cycle where you ovulated. Put together, that tells you whether stress hormones are running high or flat and whether sex hormones are low at the same time.
It can’t show a steal, because there isn’t one to see. And it is one day: a bad night or an unusual day can shift it. Read it as a pattern on that day, alongside your symptoms and cycle history.
Stress lowers sex hormones by changing the signals from the brain, not by raiding a shared ingredient. That is better news than it sounds: it means the list of things worth checking is longer, and more of them are fixable.
Sources
- Endotext. Adrenal Androgens. NCBI Bookshelf NBK278929. ncbi.nlm.nih.gov/books/NBK278929
- Whirledge S, Cidlowski JA. A role for glucocorticoids in stress-impaired reproduction: beyond the hypothalamus and pituitary. Endocrinology 2013;154:4450–68. PMID 24064362. doi:10.1210/en.2013-1652
- Gordon CM et al. Functional hypothalamic amenorrhea: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab 2017;102:1413–39. PMID 28368518. doi:10.1210/jc.2017-00131