002: Why Stress Feels Different in Your 40s — The Hormonal Shift Behind It

Something feels off — and it's hard to explain.

You've always been someone who handles stress. Hard things would come up and you'd deal with them. That has been your baseline for as long as you can remember.

And lately, that baseline feels different: Small things hit harder than before. Emotions arrive that feel bigger than the situation warrants. You find yourself more reactive than usual — and it surprises you.

For women in their 40s and 50s navigating perimenopause and the years that follow, this is one of the most unexpected experiences of this season. And it has a specific biological explanation.

By the end of this episode, you'll know exactly what's driving the emotional intensity you may be feeling right now — and one thing you can do today that directly supports your nervous system in the moment.

The progesterone and GABA connection

Progesterone is often called the calming hormone — and there is a specific biological reason for that.

Inside the brain, progesterone converts into a neurosteroid called allopregnanolone. This compound works directly on GABA receptors — the system responsible for calming and regulating the nervous system.

When progesterone is well supported, your nervous system has a natural buffer. Stress comes in, your body processes it, and you return to balance. This feels normal — so you usually don't notice it until it shifts.

During perimenopause — often beginning in the 40s and continuing into the 50s and 60s — progesterone is usually the first hormone to shift, and it shifts before estrogen.

As progesterone shifts, allopregnanolone shifts with it. This changes how GABA — the brain's primary calming chemical — functions. Your nervous system now has a different level of calming support than it used to. The same stressors you used to move through without much effort now produce a reaction that feels out of proportion. The hormonal shift is doing most of the driving.

Estrogen plays a role too. Estrogen supports serotonin production — the neurotransmitter most connected to mood and the feeling that life is manageable. As estrogen rises and falls during these years, serotonin rises and falls with it. This is why the emotional experience can feel so inconsistent — better some days, harder on others — in a pattern that has nothing to do with what is happening in your outside life. It is coming from your internal hormonal patterns.

The gut connection

More than 90% of the body's serotonin is produced in the gut — not the brain. The gut and the brain are in constant communication through the vagus nerve and the hormonal system. The state of your gut directly affects the neurotransmitters available to your brain.

When gut bacteria shift during this hormonal season — in response to changing estrogen levels — the microbial communities that support serotonin production can become disrupted. A less diverse gut microbiome produces less serotonin. And less serotonin is associated with changes in mood and a lower threshold for emotional intensity.

This is why emotional changes and digestive changes so often show up at the same time during this season. They share a root cause. The gut and the brain are one connected system responding to the same hormonal shift — and when you support one, the other tends to improve too.

The cortisol piece

There is one more layer worth understanding.

Cortisol is the body's primary stress hormone. During this season, cortisol patterns can shift — including when cortisol rises and falls and overall cortisol levels.

Cortisol and progesterone share the same raw materials in the body. When cortisol production increases, fewer resources are available for progesterone. This means chronic stress — physical or emotional — draws from the same pool your body needs to make progesterone, which supports GABA, the brain's primary calming chemical.

These systems influence each other. Hormonal patterns affect how your body responds to stress. And stress patterns influence hormone production. Understanding that loop is the first step toward supporting it.

A note from my own experience

This particular aspect of the hormonal shift wasn't part of my own experience — my symptoms were physical. But I've spoken with enough women to know how disorienting this is. The calm that used to just be there now takes more effort to create. And without knowing why it's happening, it can feel really confusing — like something has changed but you're not sure why.

Understanding what your body is doing changes that. When you know what is driving these reactions, you can begin to recognize the pattern — when it happens, what tends to come before it, and what your body is asking for in that moment.

Your takeaway from today

One of the most direct ways to support your nervous system in the moment is through a simple breathing practice called box breathing.

Here's how it works: Breathe in for 4 seconds, hold for 4 seconds, breathe out for 4 seconds, and hold again for 4 seconds. Repeat for a few minutes.

As your breathing slows and becomes more even, your body receives a signal of safety and your nervous system begins to calm. You can also place a hand on your heart as you breathe — this gives your body a physical point of focus and makes the calming response more effective.

This works because it directly influences your vagus nerve and supports your parasympathetic nervous system — the part of your body responsible for rest and regulation. It supports GABA, the brain's primary calming chemical. It doesn't address the root cause on its own — but it gives you a way to support your body in the moment rather than simply waiting for it to pass.

The root cause is hormonal and nutritional. And that is exactly where Nourish begins.

Nourish is my 21-day ancestral nutrition immersion — designed for the woman who is ready to give her body what it actually needs to thrive during this season of life. It includes daily education, recipes, shopping lists, a suggested menu plan, and a bonus masterclass called Nourishing Your Hormones, for women in their 40s, 50s, and 60s navigating perimenopause and the decades that follow. You'll find it at nourishwithkatrina.com/nourish.

To your vibrant health and freedom,
Katrina