A plain-language, continually updated guide from Dr. Matt Chalmers’ clinical reference on hormones and peptides.
Cortisol is a hormone produced by your adrenal glands in response to signals from your brain’s hypothalamic-pituitary-adrenal (HPA) axis. It plays a central role in your stress response, blood sugar regulation, and inflammatory signaling — but chronically elevated cortisol is arguably the most clinically significant, and most commonly overlooked, suppressor of healthy hormone function in modern life.
This mechanism operates on multiple levels at once, and it’s worth understanding in full because it explains a lot of hormone symptoms that don’t show up as an obvious “cortisol problem” on paper. At the brain level, cortisol suppresses the signals that drive your sex hormone production. At the gland level, cortisol directly interferes with the enzymes needed to build both DHEA and testosterone. And at the raw-material level, your body preferentially shunts pregnenolone (the universal building block for all steroid hormones) toward making more cortisol during sustained stress — leaving less available for testosterone, DHEA, and estrogen production. This is sometimes called “pregnenolone steal” or “cortisol steal,” and it’s a genuinely useful concept for understanding why chronic stress and poor sleep can tank your other hormones even when nothing else appears wrong.
The relationship runs in both directions, too: low testosterone actually makes your stress response more reactive, which drives cortisol higher, which suppresses testosterone further — a downward spiral that’s hard to break by addressing either piece alone.
Video summary: Cortisol is the body’s response to stress, so persistently high cortisol is a sign of ongoing stress that needs attention. When it stays elevated, cortisol can push fat storage toward visceral (belly) fat and interfere with thyroid and testosterone function. Dr. Chalmers explains that a saliva test, collected several times from waking to bedtime, shows how cortisol rises and falls through the day; a healthy pattern rises in the morning and falls by evening, while a level that rises and stays high is a concern.
Helpful ways to bring cortisol down include regular exercise such as running or weight training, meditation, prayer and a daily gratitude practice. If you don’t feel especially stressed but your cortisol stays high, it can help to talk with a qualified professional about past or ongoing stressors. Keep tracking your levels, and work with a provider if they don’t improve.
“The best way to reduce the damage from chronic stress and cortisol is motion. Resistance training, weight lifting, is the best option for this… Getting quality sleep is the next best way to circumvent the damage stress does to your hormone system. This is one of the most overlooked and troublesome areas we have in modern lifestyles.”
— Dr. Matt Chalmers, The Pillars Path: A Root-Cause Guide to Hormones, Peptides, and Metabolic Health
The adrenal glands contain some of the highest concentrations of vitamin C in the body, which serves as a cofactor in cortisol synthesis. Vitamin B5, B6, and magnesium are also commonly discussed in relation to healthy adrenal hormone production — magnesium in particular plays a documented role in modulating the HPA axis and reducing excess cortisol output.
Cortisol itself (as hydrocortisone) is FDA-approved as a prescription therapy for diagnosed adrenal insufficiency. Evaluation of cortisol patterns is done through lab testing with our providers.
Cortisol is the body’s primary stress-response hormone, and its production follows a normal daily rhythm regulated by the HPA axis. Hydrocortisone (cortisol) is FDA-approved for diagnosed adrenal insufficiency. Evaluating cortisol patterns — not just single values — is typically done through lab testing with our providers, alongside lifestyle factors like sleep, resistance training, and stress load that our reference material identifies as the most impactful levers for most people.
Both can reflect different underlying issues with the HPA axis; a full pattern (often via multiple-point testing) gives more clinically useful information than a single measurement.
This page draws on The Pillars Path: A Root-Cause Guide to Hormones, Peptides, and Metabolic Health by Dr. Matt Chalmers — Pillars of Wellness’ clinical reference on hormone and peptide therapy.
