Perimenopause & Energy: How to Support Your Body Through Hormonal Changes

Feeling Exhausted in Your 40s? It’s Not Just You

If you’re in your 40s and suddenly feel like your energy has vanished, you’re not imagining it. The afternoon crashes, difficulty getting out of bed, reliance on caffeine, and unpredictable mood swings aren’t just a side effect of getting older - they’re often a sign of perimenopause, the transition leading up to menopause.

This is something I see in clinic all the time. Women who are doing "all the right things" but still feel like they’re running on empty.

Perimenopause can start as early as your late 30s or early 40s and last anywhere from 4 to 10 years. During this time, your hormones fluctuate significantly, impacting everything from energy and metabolism to mood, sleep, and brain function.

If you’ve been feeling exhausted no matter how much sleep you get, struggling with motivation, or noticing an increase in stress and anxiety, it’s time to look at how your hormones are affecting your energy, and what you can do about it.

What’s Happening to Your Hormones in Perimenopause?

Perimenopause is a gradual process, not an overnight change. It’s marked by fluctuations in oestrogen, progesterone, and cortisol, all of which play a direct role in energy levels, metabolism, and nervous system regulation.

The Key Hormones Affecting Your Energy

• Oestrogen – Helps maintain energy, mood, and brain function. During perimenopause, oestrogen becomes erratic, leading to fatigue, brain fog, mood swings, and increased stress sensitivity.

• Progesterone – Known as the “calming hormone”, progesterone helps with sleep, stress management, and inflammation control. Its levels start to decline in perimenopause, making it harder to feel rested and resilient to stress.

• Cortisol – Your stress hormone. As oestrogen and progesterone fluctuate, cortisol can become dysregulated, leading to chronic fatigue, disrupted sleep, and increased belly fat storage.

• Thyroid Hormones – Changes in oestrogen and progesterone can also impact thyroid function, which controls metabolism and energy production. Many women experience undiagnosed thyroid slowdowns in perimenopause, worsening fatigue.

The Result? An Energy Crisis

When these hormones shift, your body can’t regulate energy as efficiently, making you feel constantly drained, overwhelmed, and mentally foggy. But the good news is, there are proven strategies to support your body through these changes.

How to Support Your Energy Levels During Perimenopause

1. Balance Blood Sugar to Avoid Energy Crashes

If you’re reaching for caffeine or sugar to get through the day, you’re likely dealing with blood sugar instability, a key factor in perimenopausal fatigue.

How to Keep Blood Sugar Stable

• Start your day with protein & healthy fats – Swap toast or cereal for eggs, avocado, nuts, or Greek yoghurt to keep blood sugar steady.

• Eat regular meals – Skipping meals can spike cortisol, worsening energy crashes. Aim for balanced meals every 4-5 hours.

• Reduce refined carbs – Processed carbohydrates (like white bread, pastries, and pasta) cause quick energy spikes followed by crashes. Instead, focus on whole grains, fibre, and protein.

2. Support Your Nervous System to Reduce Cortisol Overload

Chronic stress is one of the biggest drivers of perimenopausal fatigue. As oestrogen and progesterone decline, your body becomes more sensitive to stress, making cortisol levels harder to regulate.

Simple Ways to Lower Cortisol

• Prioritise deep rest – Short, intentional breaks during the day reduce cortisol build-up.

• Breathe to regulate your nervous system – Slow, deep breathing (like 4-7-8 breathing) lowers stress hormones in minutes.

• Daily movement (but not excessive cardio) – Over-exercising (especially long cardio sessions in combination to insufficient fueling) can raise cortisol further. Instead, opt for strength training, walking, and yoga, which support hormonal balance.

3. Get More (and Better) Sleep

Perimenopause often brings disrupted sleep, early waking, and night sweats, all of which drain energy reserves.

How to Improve Sleep During Perimenopause

• Get morning sunlight – Exposure to natural light regulates melatonin, helping you fall asleep more easily at night.

• Limit caffeine after midday – Caffeine clearance slows down in perimenopause, making afternoon coffee more likely to disrupt sleep.

• Support progesterone naturally – Magnesium-rich foods (like leafy greens, nuts, and dark chocolate) help calm the nervous system and improve sleep quality.

4. Optimise Your Diet for Hormonal Balance

Certain nutrients and dietary habits can support your body through perimenopause and help stabilise energy levels.

Key Nutrients for Energy & Hormonal Support

• Magnesium – Supports progesterone, reduces stress, and improves sleep (found in almonds, spinach, and dark chocolate)

• B Vitamins – Help convert food into energy and support brain function (found in eggs, lean meat, and leafy greens)

• Omega-3s – Reduce inflammation and support mood and energy (found in salmon, flaxseeds, and walnuts)
  Adaptogens – Herbs like ashwagandha and rhodiola support cortisol balance and stress resilience

The Bottom Line: You Don’t Have to Accept Fatigue as Your New Normal

Perimenopause is a natural transition, but feeling exhausted, foggy, and out of balance isn’t something you have to put up with. By focusing on blood sugar balance, stress regulation, quality sleep, and a nutrient-dense diet, you can support your body through hormonal changes and reclaim your energy.

Want more personalised support?

Book a free 15-minute discovery call or explore the diet lifestyle revamp to get started with nervous system-first support for energy and hormones.