The Hormonal Shift After 35

Understanding estrogen, progesterone, stress, gut health, brain fog, libido, and why so many women stop feeling like themselves during perimenopause.

Just before I turned 40, I became deeply curious about what this new decade would hold for me.

In previous decades, I mostly thought about things like career, travel, relationships, and building a life. But as I approached my forties, my curiosity shifted inward. I started wondering:

What is going to happen inside my body as I age?

We hear about menopause long before we experience it ourselves. Maybe your mother shared parts of her journey with you. We hear about hot flashes, emotional mood swings, stubborn weight gain, poor sleep, anxiety, and feeling unlike ourselves.

My own mom had quite an intense experience and shared a lot with me over the years. And as I entered my forties, I realised I didn’t want to wait until symptoms arrived before learning what was happening in my body.

I wanted to understand:

• what changes hormonally during this transition,

• why women suddenly feel so different,

• and most importantly:
  what can we actually do to support our bodies well during this phase of life?

This is where my passion for perimenopausal health truly began.

Two things I want to clarify:

1. Now, you may or may not have “symptoms” yet. For a long time, I personally didn’t notice major signs either. But because I spend so much time studying health, hormones, and body awareness, I now pick up subtle changes quite quickly.

2. And you may still fall within the perimenopause age range while feeling completely “normal.” That’s important to understand too. Because perimenopause often begins long before most women realise it.

Hormones Are Chemical Messengers

Hormones are chemical messengers. They tell your body what to do, when to do it, and how strongly to respond. They influence how you store or release fat, how hungry you feel, how deeply you sleep, how stable your mood is, how well you handle stress, and how much energy you have throughout the day.

And hormones never work in isolation. They function as a web. When one shifts, the others respond.

This is why hormonal changes can feel so confusing.

You may think:

• it’s just anxiety,

• I just sleep poorly,

• It’s just bloatinging,

• just low libido,

• just fatigue,

• just brain fog,

• or just stress.

But often these symptoms are connected through hormonal shifts happening underneath the surface.

The Hormonal Shift After 35

As we spoke about in “How Do You Know You’re in Perimenopause?” (the first article in this series), most women associate hormonal changes with menopause. But for many women, hormonal shifts actually begin much earlier - often as early as the mid-to-late thirties. During this phase, estrogen and progesterone, two of your primary female hormones, begin fluctuating as the body slowly prepares for its next hormonal chapter.

And while some women are very familiar with hormones and how they work, many of us were never really taught what these hormones actually do inside the body.

I know I certainly wasn’t.
So let’s explore them together.

Let’s start with estrogen.

Estrogen is often labelled a “female hormone,” but its role goes far beyond reproduction or your menstrual cycle.

Estrogen influences:

• metabolism,

• insulin sensitivity,

• mood,

• brain function,

• gut health,

• libido,

• bone density,

• inflammation,

• skin,

• energy production,

• and even how resilient you feel emotionally.

That’s a lot of responsibility for one hormone.

As estrogen begins fluctuating during the late 30s and 40s, many women notice:

• increased bloating,

• more fat stored around the belly,

• anxiety,

• mood swings,

• fatigue,

• brain fog,

• digestive changes,

• poor sleep,

• lower stress tolerance,

• or simply feeling unlike themselves.

This isn’t your body failing. It’s your body recalibrating to a new hormonal environment.

So we need to stop treating our bodies like they are problems to fix.

This phase of life asks for more support.
More nourishment.
More rest.
More compassion.
Not more punishment.

At the same time, progesterone, often called the calming hormone, also begins declining. Progesterone helps soothe the nervous system, supports sleep, balances estrogen, and helps regulate anxiety and fluid retention.

Considering this, it makes complete sense that when progesterone drops, many women begin feeling:

• more wired,

• more anxious,

• more emotionally sensitive,

• less resilient to stress,

• and more exhausted.

This is one of the reasons stress suddenly feels harder to manage after 35.

What We Were Never Properly taught

While aging is absolutely part of life, most women were never properly taught how profoundly hormones affect the entire body.

Your hormones affect your gut — and your gut affects your hormones.

As we mentioned earlier, when estrogen changes, many women experience bloating, constipation, food sensitivities, slower digestion, or increased inflammation. Often, these are signs that the gut and hormonal system are no longer communicating as smoothly as before.

Hormonal shifts also influence libido, intimacy, emotional regulation, and relationships.

Sadly, this is often the phase where women silently begin wondering: “What’s wrong with me?”

But low libido, emotional exhaustion, anxiety, and feeling disconnected are often not simply psychological.

They can be deeply physiological.

And because hormones also affect mitochondrial energy production, the tiny energy systems inside your cells, many women begin experiencing fatigue, poor recovery, brain fog, and that “wired but tired” feeling. (If you missed my Mitochondria Health article, read it here.)

Do you notice the thread connecting all of this, and the profound effect hormones can have on your biology, nervous system, and emotional wellbeing?

Women are often taught to expect suffering during hormonal transitions instead of understanding. But understanding changes everything.

A Gentle Note About Modern Life

One thing I’ve also become increasingly aware of is how much modern life influences our hormones.

We are surrounded daily by artificial light, ultra-processed foods, and environmental toxins. We think overstimulation and chronic stress is normal. It’s not.

I was shocked when I learned that certain chemicals found in plastics, fragrances, cosmetics, receipts, and food packaging can mimic estrogen-like activity. Imagine the added confusion to an already fluctuating hormonal system inside your body.

This doesn’t mean we need to panic or become obsessive but it does invite awareness. Small shifts like reducing plastic food containers, avoiding heating food in plastic, filtering water where possible, and becoming more conscious of what we place on and inside our bodies can become supportive acts of care during this phase of life.

This Is a Different Season

This phase of life can become the beginning of a much deeper relationship with your body, one rooted in awareness, understanding, and greater respect for what your body is navigating hormonally, instead of constant criticism or control.

Most women spend years trying to manage their bodies through restriction, discipline, and pushing harder. But after 35, the body often responds very differently.

So, here is my invitation to you: approach this season with curiosity, compassion, and support for your body.

This is your new beginning.

Next week, we’ll explore one of the biggest hidden drivers behind hormonal symptoms after 35: “Stress”, and why so many women are living in survival mode without even realising it.

Xoxo
Cerina