What no longer serves, needs to leave

Menopause as a rebuild of the brain and of life

3 a.m., a bedroom in Munich. A woman, 47, wakes up drenched in sweat. Her heart is racing, a heat rising from the inside. She lies awake thinking about things she has carried for years. The next day, in a meeting, a word she has used a thousand times escapes her. On the drive home she cries in the car without quite knowing why.

And months later she says a sentence I hear very often in my work: "I'm not doing this anymore."

Many people read that sentence as exhaustion. Neuroscience suggests a different reading: it may be the visible end of a rebuild that started in the brain long before.

The brain doesn't just build, it also clears out

We like to think of learning as growth: more connections, more knowledge, more capacity. But the brain works just as much through reduction.

During puberty, grey matter decreases in many brain regions. This is not decline, it is maturation. Synapses that are rarely used are removed. Connections that are used often are strengthened. Researchers call this synaptic pruning, like cutting back a fruit tree. The principle behind it is "use it or lose it". What isn't needed disappears. What remains becomes more efficient.

The same pattern appears in pregnancy. A study in Nature Neuroscience found reductions in grey matter in first-time mothers, in regions involved in social cognition. These changes were linked to the bond with the baby and were still detectable two years later (Hoekzema et al., 2017). Less volume, but more targeted function.

Puberty, pregnancy, menopause: neuroscientist Lisa Mosconi describes all three as hormonally driven rebuilding phases of the female brain.

What happens in the brain during perimenopause

Estradiol is not just a reproductive hormone. In the brain it acts as a neurosteroid. It influences how many connections nerve cells form in the hippocampus and prefrontal cortex, regulates the energy supply of the cells, and modulates the serotonin and dopamine systems.

During perimenopause, this hormone often fluctuates irregularly for years before it eventually declines. The brain has to adapt. Mosconi and her team studied 161 women using brain scans. Structure, connectivity and energy metabolism changed depending on menopausal status, not on age. After menopause, many of these measures partly stabilized again (Scientific Reports, 2021). The researchers interpret this as a sign of adaptation: the brain finds a new balance.

Cognition follows the same arc. In the large US cohort study SWAN, many women's learning performance stalled during perimenopause and recovered afterwards (Greendale et al., Neurology, 2009). For most women, the fog is a phase, not an end state.

Less energy forces prioritization

The brain uses around 20% of the body's energy. Estrogen helps nerve cells use glucose. When it declines, the brain has less fuel available. Neuroscientist Roberta Brinton therefore describes perimenopause as a bioenergetic transition, in which the brain also shifts to alternative fuels such as ketones. A system with less energy can no longer run everything at once. It has to decide what it keeps supplying.

This is where biology becomes a life question. Many women find that things which somehow worked for years suddenly don't anymore. The evening appointment after a packed day. The role of the one who catches everything. The relationship that has long been one-sided. The job that has become nothing but obligation. Tolerance for the trivial drops. Clarity about what matters rises.

That is not a character flaw. It fits a brain that is reallocating its resources.

Rebuild, not breakdown

Neuroplasticity has no built-in direction. A brain in transition learns helpful patterns as quickly as harmful ones. Women who simply push through this phase without consciously changing anything risk exhaustion, withdrawal and self-doubt settling in as new patterns. The risk of depressive symptoms is significantly higher during perimenopause.

Those who see it as a restructuring, on the other hand, can decide deliberately what to strengthen and what to let go.

What supports the brain in this phase is well documented and unspectacular:

• Sleep, because even one bad night makes the amygdala, the brain's alarm system, noticeably more reactive.

• Movement, especially endurance training, because it boosts BDNF, a growth factor that supports new connections between nerve cells.

• New learning, because connections that are used, stay.

• Supportive relationships and meaningful work, because they regulate the stress system.

• Medical support, for some women including hormone therapy, weighed individually with their doctor.

And perhaps the most uncomfortable measure of all: letting go of what no longer holds. The brain shows us how.

What this means for organizations

Many women go through this rebuild exactly when they bring the most experience, responsibility and leadership to the table. "I'm not doing this anymore" can end in a resignation. But it can also be the beginning of a realignment the organization benefits from: clearer priorities, less patience for inefficient processes, more focus on what really counts. Which way it goes is rarely decided in a one-on-one conversation. It is decided by culture. As long as there is no language for this phase, women stay silent, managers guess, and good people leave without anyone knowing the real reason.

It shows up in three places that matter to every organization:

• Productivity. Poor sleep, difficulty concentrating and word-finding problems cost performance, often unnoticed. Knowing what helps in this phase means you can respond in a targeted way instead of misreading changes in performance.

• Trust. When Google studied what makes its best teams work in "Project Aristotle", one factor came out on top: psychological safety. The trust that you can speak openly without fearing negative consequences. High-performing teams emerge where people are allowed to say that something isn't working right now. A woman who has to hide her perimenopause spends energy on concealing instead of on her work. A team where it can be talked about gets that energy back.

• Loyalty. People who feel seen during their most demanding phase stay. People who feel left alone leave, and take decades of experience with them.

This is exactly where Cycle Positivity comes in. In our data-driven culture change programs, we start by finding out what the women in your organization actually experience and need. From that, we develop a shared language that lets employees, managers and teams talk openly about the menstrual cycle, perimenopause and menopause. And we measure what changes: in productivity, trust and retention.

Menopause is not decline. It is a rebuild. And as with any rebuild, what stands at the end is decided during construction.

If you'd like to know what the women in your organization need to go through this rebuild with their experience and expertise on board, send me a message at alissia@cyclepositivity.com. I look forward to the conversation.

Sources Brinton et al. (2015), Nature Reviews Endocrinology · Edmondson (1999), Administrative Science Quarterly · Google re:Work (2015), Project Aristotle · Greendale et al. (2009), Neurology · Hoekzema et al. (2017), Nature Neuroscience · Mosconi et al. (2021), Scientific Reports