If you’re somewhere in your mid-to-late 40s and you’ve noticed that your mood, sleep, cycle, and even your jeans feel different lately, you are not imagining it, and you are definitely not alone. This PERIOD of life (pun fully intended) tends to arrive without much warning. The good news is that it’s also one of the most important windows you’ll ever have to invest in your health.
Here’s the reframe I want you to walk away with: perimenopause is not just a hormonal event. It’s a neurological and metabolic transition. During these years, your hormones don’t politely decline in a straight line. They swing, surge, and drop unpredictably, and your brain feels every bit of it.
This is exactly what neuroscientist Dr. Lisa Mosconi describes in The Menopause Brain. She makes the case that menopause is not something that simply happens to your ovaries. It’s a transition in which your brain takes center stage. Estrogen is one of your brain’s most protective allies. It supports blood flow, helps your neurons communicate, and fuels the brain’s ability to use glucose for energy. So when estrogen starts behaving erratically, your brain notices first, often before your period ever changes.
So if you’ve been feeling “not like yourself” lately, with more anxiety, irritability, low motivation, brain fog, or those out-of-nowhere waves of sadness, please hear this: those feelings are real, and they have a biological story behind them. As Dr. Louann Brizendine lays out in The Female Brain, a woman’s neurochemistry is shaped by her hormones at every stage of life, from puberty to pregnancy to perimenopause. The erratic hormonal swings of these years reliably show up as shifts in mood, sleep, and emotional reactivity. It’s the very real conversation happening between your hormones, your brain, your nervous system, and inflammation.
The most empowering part? Once you understand what’s actually happening, you can support it. With the right nutrition, movement, and lifestyle rhythms, perimenopause can shift from feeling like a slow unraveling into something that’s genuinely steadying and, dare I say, transformative.
Your hormones still have a rhythm, even now
Even when your cycle becomes irregular, your hormones often keep their monthly ebb and flow. What changes is the intensity and the unpredictability of the surges and crashes, especially with estrogen and progesterone.
Dr. Lara Briden has a wonderful way of framing this in the Hormone Repair Manual. She calls perimenopause a kind of “second puberty,” a recalibration rather than a simple winding down. The rhythm is still there. Someone just turned the volume knob up and left it spinning.
Let me walk you through the main players.
Estrogen, the amplifier
Estrogen is the hormone we tend to associate with feeling vibrant, focused, and emotionally open. Brizendine connects rising estrogen to a boost in serotonin and dopamine, which helps explain why your mood and motivation can feel so much better on your higher-estrogen days.
When estrogen is rising, you may notice your mood lifts, your words come more easily, and you feel more creative and connected. When it swings rapidly, the opposite can happen: more anxiety, heightened sensitivity to noise and light, and emotions that feel turned all the way up. Because estrogen supports both serotonin and your brain’s glucose metabolism (a point Mosconi emphasizes in The Menopause Brain), a sudden drop can feel like a genuine crash. That’s the irritability or low mood that seems to come from nowhere.
Progesterone, the calming one
Progesterone is your body’s natural chill pill. As Briden explains, it boosts GABA activity in the brain, which is part of why it helps you relax and sleep.
When progesterone is steady, your nervous system settles, your sleep improves, and you tend to feel more emotionally resilient. When it dips, which happens a lot in perimenopause, you can end up feeling “wired but tired,” waking at 3 a.m., and noticing that small things tip you into anxiety or overwhelm.
Here’s one of Briden’s most useful insights: because ovulation becomes less reliable in perimenopause, progesterone often drops before estrogen does. That leaves you in a state of relative estrogen dominance, which can crank up mood swings and sleep problems well before your periods ever stop. If you’ve felt like something was off but your labs looked “normal,” this is often why.
Testosterone, the quiet motivator
Testosterone gets overlooked, but it matters for energy, confidence, and mental clarity. When it’s balanced, you tend to feel more driven, more physically vital, and more interested in, well, life. When it dips, fatigue, low confidence, and brain fog can creep in. Briden reminds us that testosterone shifts during this transition too, and it deserves attention rather than a shrug.
Cortisol, the one that touches everything
Cortisol isn’t a reproductive hormone, but it has its hands on all of them. Chronic stress disrupts the HPA axis (your stress-response system), which talks directly to your reproductive hormones. Both Briden and Dr. Daniel Amen, in Unleash the Power of the Female Brain, treat stress regulation as foundational, not optional.
When cortisol stays high, your body prioritizes making stress hormones, which can come at the expense of progesterone. Your blood sugar gets shaky, which fuels mood swings, and your sleep suffers, which makes the whole hormonal picture worse. Getting a handle on stress is so often the missing piece in feeling stable again.
Why your mood feels so much less steady
Your hormones and your brain chemistry are deeply intertwined. As estrogen fluctuates, it pulls on serotonin (mood), dopamine (motivation), and acetylcholine (focus and memory). Those are the exact hormone-to-brain links Brizendine maps out in The Female Brain.
At the same time, shifts in metabolism, blood sugar, and gut health can stoke low-grade inflammation in the brain, which makes everything feel more reactive. Mosconi connects this directly to a kind of energy shift in the brain during the menopause transition, and she’s clear that perimenopause is a uniquely important window for protecting your long-term brain health.
The big-picture takeaway: this isn’t “just hormones.” It’s a full neuroendocrine and metabolic recalibration. And that’s actually good news, because it means there are a lot of levers you can pull.
Eating to steady your mood
Food is one of your most powerful tools here. It can stabilize blood sugar, calm inflammation, and give your brain the raw materials it needs to make feel-good neurotransmitters. What I love is that all of these authors land in almost exactly the same place, just coming at it from different angles.
Stabilize your blood sugar first. This is the cornerstone for both Amen and Briden. Amen says it again and again: let your blood sugar crash and you sabotage your mood, focus, and decision-making. So aim for protein at every meal, plenty of fiber-rich vegetables, healthy fats like olive oil, avocado, and nuts, and go easy on refined sugar and processed carbs. Blood sugar dips can feel exactly like hormonal anxiety, so steadying your meals often steadies your emotions.
Support how your body processes estrogen. Your liver and gut do the work of clearing estrogen efficiently, something Briden covers in real depth. Cruciferous vegetables (broccoli, arugula, cauliflower), flax and chia seeds, and high-fiber plants all help keep estrogen from over-stimulating your nervous system.
Feed your brain anti-inflammatory fats. Omega-3s support mood and calm brain inflammation, and both Mosconi and Amen single them out as essential. Think wild salmon, sardines, walnuts, and algae-based omega-3s if you’re plant-based.
Don’t skimp on protein. This is where exercise physiologist Dr. Stacy Sims comes in. In Next Level, her guide to training and eating through menopause and beyond, she is blunt about the fact that most women in this stage are eating far too little protein right when they need it most. Her ballpark is roughly 1.8 to 2 grams of protein per kilogram of body weight per day, which works out to something like 30 grams per meal. Protein protects your muscle, steadies your blood sugar, and gives your brain the building blocks for neurotransmitters. Sims also recommends skipping fasted workouts in this stage and getting protein in soon after you train.
Don’t forget your minerals. Magnesium, zinc, and vitamin B6 help regulate neurotransmitters and promote calm. Magnesium and B6 in particular sit right at the heart of Briden’s foundational support stack. You’ll find them in pumpkin seeds, dark leafy greens, lentils, and bananas.
Moving and living in a way that supports your hormones
Food matters enormously, but it’s only part of the picture. Your hormones also respond to how you move, how you sleep, and how you process stress and emotion.
Lift heavy, and don’t be shy about it. This is Sims’s signature message, and it’s a big shift for a lot of women who came up in the cardio era. In Next Level, she makes the case that as estrogen declines, your body responds best to a real strength stimulus. That means heavy resistance training a few times a week with compound lifts (think squats, deadlifts, presses) in a lower rep range that actually challenges you. She also points to short, hard efforts like sprint intervals and a bit of jump training to protect your bones and your metabolism. Long, grinding cardio is no longer the hero of the story. Briden, Amen, and Mosconi all agree that strength work is protective for your metabolism and your brain.
Treat sleep like medicine. Deep sleep supports progesterone and helps regulate cortisol. A consistent bedtime, a wind-down routine, and dimming the lights in the evening all help. Mosconi considers sleep one of the most powerful levers you have for protecting your brain through this transition.
Calm your nervous system on purpose. Breathwork, mindfulness, gentle somatic practices, even a daily walk outside all help quiet the HPA axis and take the edge off those cortisol-driven swings.
Stay connected. Perimenopause often lands right in the middle of big life changes. Brizendine’s work shows just how central connection and relationship are to the female brain, which is part of why leaning on friends, a therapist, or a community group helps you move through the emotional shifts rather than white-knuckle past them.
A different way to see this season
Perimenopause gets framed as a season of loss: of fertility, of youth, of feeling steady. But Mosconi makes the opposite case in The Menopause Brain. She describes menopause not as an ending but as a transition, one your brain is actively adapting and rewiring to navigate. Many women come out the other side feeling clearer, more grounded, and more themselves, not less.
When you support your body with nourishing food, intentional movement, real sleep, and a calmer nervous system, those wild hormonal swings start to lose their grip. The goal isn’t to fight your body. It’s to work with the intelligence of your hormones, honoring the natural ebb and flow while giving your brain and body what they need to stay steady.
You are not broken. You are recalibrating. And you have far more say in how that goes than anyone ever told you.
📍 Tara Trebesch, Therapist, CN, IHP, CFA Integrative Health & Psychotherapy Park City, Utah | taratrebesch.com
References
Briden, L. (2021). Hormone Repair Manual: Every Woman’s Guide to Healthy Hormones After 40. Greenpeak Publishing.
Mosconi, L. (2024). The Menopause Brain: New Science Empowers Women to Navigate the Pivotal Transition with Knowledge and Confidence. Avery.
Sims, S., & Yeager, S. (2022). Next Level: Your Guide to Kicking Ass, Feeling Great, and Crushing Goals Through Menopause and Beyond. Rodale.
Amen, D. G. (2013). Unleash the Power of the Female Brain: Supercharging Yours for Better Health, Energy, Mood, Focus, and Sex. Harmony.
Brizendine, L. (2006). The Female Brain. Morgan Road Books.