The Pregnenolone Steal: How Stress Hijacks Your Hormones

Tammy Miller
Oct 20
5 min read

The preg-nen-o-lone steal, it may be tricky to pronounce, but what matters most isn’t getting the name right, it’s understanding the steroidal hormone pathways and what’s happening physiologically in the body when we feel stressed.

When I was studying Naturopathy, we were taught that stress can disrupt the hormonal balance. Over the years, I’ve shared this with clients and friends, "Stress can throw your hormones out of sync", but what does this really mean? How does feeling stressed or anxious actually interfere with your body’s hormones?

Ever heard of couples trying to conceive for years, only to fall pregnant while on a holiday? Why is this?

They basked in the sun, dined out, ate fresh foods, received massages, switched off their minds and finally relaxed. It’s a story I hear often and it can be explained.

When you are truly relaxed, chilling by the ocean, getting enough sleep, spending time in nature, free from cooking and daily demands - your nervous system finally takes a break too. You stop the stress loop.

Cortisol, the stress hormone, steps aside, no longer hijacking the delicate balance of your reproductive hormones. The hormones that support your menstrual cycle and then fertility begins to flow again. Your body stops buzzing with nervous tension and starts breathing again. And in that harmonious state, conception becomes possible.

This blog isn’t about fertility specifically, but it’s a powerful example of how stress can disrupt the natural flow of hormone production. When we learn to CALM the nervous system, we create space for healing, balance and renewal - whether that’s for fertility, energy or emotional wellbeing.

So what’s actually happening?

What is the Pregnenolone Steal?

Pregnenolone is a steroid naturally produced in the adrenal glands, derived from cholesterol and the precursor to steroidal hormones including: progesterone, testosterone, the oestrogens, dehydroepiandrosterone (DHEA) and cortisol.

When we are constantly in a state of stress, your body shifts its priorities. Instead of distributing pregnenolone evenly across all steroidal hormonal pathways, it diverts it toward cortisol production - your primary stress hormone. This is known as the pregnenolone steal.

To help you visualise what’s happening inside the body, I’ve included the Steroid Hormone Cascade diagram below. You’ll see I’ve highlighted in yellow where cortisol production can dominate the hormonal pathway during times of stress. Cortisol draws heavily from pregnenolone, the shared precursor for many other vital hormones. As a result, those other hormones receive less support and the delicate feedback loop that keeps our hormonal system in balance becomes disrupted.

Figure 1: The Steroid Hormone Cascade, highlighting the Pregnenolone steal (Nutripath, 2018)

The Role of Cortisol

Cortisol plays an important role in maintaining balance within the body. While it’s best known as the “stress hormone”, it has other functions. When cortisol rises, like during times of stress, it increases glucose in the blood to provide quick energy but it also plays a role in regulating metabolism, the anti-inflammatory response, modulating the immune system, blood pressure control and our sleeping patterns.

Cortisol levels naturally fluctuate throughout the day, peaking between 6-8am to help you wake up and then dropping at night to support restful sleep. This rhythm is part of your body’s internal clock, known as the circadian rhythm (Figure 2 below).

Signs of High Cortisol – Stressed & Wired

Under normal conditions, pregnenolone supports a balanced hormonal ecosystem. But when the hypothalamic-pituitary-adrenal (HPA) axis is constantly activated by stress, your body begins to favour cortisol synthesis over reproductive and mood-regulating hormones. See example below of high cortisol levels during the day (Figure 3).

Figure 3: Nutripath example report of high salivary cortisol levels throughout the day

High cortisol levels may lead to:

Sleep disturbances - waking up in the middle of the night;
Less progesterone - leading to pre-menstrual tension (PMS), anxiety, infertility and menstrual cycle issues (Explored further in Blog 3);
Lower oestrogen levels, but oestrogen dominant compared to progesterone - affecting mood, memory, and menstrual regularity;
Reduced testosterone - lack of motivation, reduced libido, reduced muscle mass, reduced strength and fatigued; and
Depleted DHEA - mood swings, decreased muscle mass, decreased bone density, memory problems, reduced libido, depression and anxiety.

Signs of Low Cortisol – Adrenal Exhaustion

We’ve explored how elevated cortisol can disrupt hormonal balance, but what happens when stress becomes chronic, stretching across months or even years?

Over time, persistent stress can lead to adrenal exhaustion, a state where the adrenal glands struggle to produce adequate levels of key hormones, including cortisol. For women between the ages of 45 and 55, this becomes especially significant. During the transition into peri-menopause and eventually menopause, oestrogen and progesterone naturally decline. With the ovaries slowing their production, the adrenal glands take on the role of supplying these hormones.

But if your adrenals are already under pressure from long-term stress, their ability to support this hormonal shift becomes compromised. The result? Depletion. Hormonal imbalances that can affect everything from mood and energy to sleep and menstrual health.

Figure 4: Nutripath example report of low salivary cortisol levels throughout the day

Symptoms of adrenal insufficiency include:

Tiredness / fatigue / low energy
Body aches
Muscle weakness
Loss of appetite and weight loss
Low blood pressure
Light-headedness / nausea
Hair loss
A change in skin colour (hyperpigmentation)
Craving salty foods
Depression

Personalised Support at Natural Inner Health

It’s not always realistic to escape on holidays or spend every day unwinding by the beach. But there are small, intentional choices we can make daily to support our nervous system, starting with the decision to choose CALM over stress. It begins with mindset: noticing when stress shows up and gently redirecting your response.

If you feel like stress is your default setting, or it’s just “how you are” it’s worth listening closely. Your body will eventually show you, revealing signs that it’s overwhelmed. These signals might show up as fatigue, exhaustion, nervousness, menstrual problems or mood swings.

To truly understand how stress is affecting your body, I recommend Salivary Hormone Testing. This non-invasive test can measure cortisol and key sex hormones, offering a clear snapshot of your stress-hormone profile.

Remember - CALM is your Superpower

Endocrine Society (2022) Adrenal insufficiency, Endocrine Society. Available at: https://www.endocrine.org/patient-engagement/endocrine-library/adrenal-insufficiency (Accessed: 19 October 2025).

Jones, C., & Gwenin, C. (2020). Cortisol level dysregulation and its prevalence—Is it nature’s alarm clock? Physiological Reports, 8(24). https://doi.org/10.14814/phy2.14644