Cortisol and your nervous system

Perimenopause often disrupts cortisol rhythms, which explains tired-but-wired feelings, poor sleep, anxiety, and daytime fatigue.

What is cortisol?

Cortisol is your primary stress hormone. It follows a daily rhythm:

• Higher in the morning (to wake you up)

• Lower in the evening (to allow sleep)

In perimenopause sex hormones fluctuate and the nervous system becomes more reactive, leading to higher baseline cortisol, bigger cortisol spikes in response to stress and cortisol staying too high in the evening

This can make you feel/have:

• ‘tired but wired’, with high cortisol at night (racing mind, poor sleep)

• poor sleep

• energy crashes in the day

• anxiety & overwhelm, emotional reactivity

What actually helps lower or stabilise cortisol?

1. Nervous system first (non-negotiable)

• Short daily breathing practices (5 minutes)

• Time outdoors / daylight

• Slowing transitions (especially morning & evening)

Not helpful:

• Pushing through exhaustion

• High-intensity everything

• “Just try harder” thinking

2. Stabilise blood sugar

• Protein in regular meals

• Avoid long fasting if tired/wired

• Reduce sugar & ultra-processed foods

• Limit caffeine (especially after midday)

3. Rethink exercise

Be cautious with stressful exercise, and prioritise recovery.

Choose walking, strength training (2–3x/week), yoga, Pilates, mobility

4. Reduce evening cortisol for better sleep

• Dim lights after sunset

• Screens off earlier

• No late workouts

• A consistent wind-down ritual

• Magnesium or herbal teas (if appropriate)

Try these approaches, instead of blaming yourself, aggressively cutting calories, over-exercising, turning to supplements!

If you are still feeling exhausted, ask your GP for tests to rule out thyroid, iron or B12 issues.