Why am I so tired during menopause?

Fatigue during menopause is frequently underestimated - both in how severe it can be and how many distinct causes it has. It's often attributed entirely to disrupted sleep, which is a factor, but the tiredness many women experience during perimenopause and menopause has roots that go beyond sleep alone. Understanding the different mechanisms helps because some of them are quite directly addressable.

The dismissal of menopausal fatigue as "just part of getting older" does real harm. The tiredness is real, it has identifiable causes, and there are specific interventions for each of them.

Menopausal fatigue isn't one thing. It's the compounding effect of several hormonal and physiological changes happening simultaneously - and each layer has its own point of intervention.

Oestrogen, mitochondria and cellular energy

What's less widely known is that oestrogen has a direct relationship with mitochondrial function - the cellular energy production process. Oestrogen receptors are present in mitochondria, and oestrogen supports mitochondrial biogenesis (the creation of new mitochondria) and efficiency. When oestrogen declines, mitochondrial function declines with it, and this has a tangible effect on cellular energy output throughout the body.

This is a different mechanism from sleep-related fatigue. It's a reduction in the cells' capacity to produce energy - the same fundamental driver as the age-related energy decline that affects everyone, but accelerated by the hormonal shift. It explains why menopausal fatigue often has a quality of physical heaviness or effort that isn't relieved by rest in the way that sleep-deprivation fatigue is.

The sleep cascade

Disrupted sleep is a major contributor to menopausal fatigue, but it's worth understanding how the cascade works. Hot flushes and night sweats fragment sleep. Progesterone's decline reduces slow-wave sleep depth. Elevated nocturnal cortisol increases wakefulness. The combined effect is sleep that feels insufficient even when its duration is technically adequate.

Chronic sleep deprivation then amplifies every other symptom of menopause - it elevates cortisol further, increases insulin resistance, worsens mood, reduces cognitive resilience, and makes the emotional demands of this period harder to manage. Addressing sleep quality isn't just about feeling more rested; it's about reducing the systemic burden that sleep deprivation imposes on an already stretched system.

Thyroid function and menopause

Thyroid dysfunction becomes more common in midlife and disproportionately affects women. The symptoms of hypothyroidism - fatigue, weight gain, low mood, cognitive slowing, cold intolerance - overlap significantly with menopausal symptoms, and the two can be difficult to distinguish without testing. Oestrogen influences thyroid hormone binding and metabolism, so hormonal changes during menopause can affect thyroid function or unmask a pre-existing subclinical issue.

It's worth ruling out thyroid dysfunction if fatigue is a prominent or dominant symptom - a simple blood test (TSH, free T4, free T3) provides clarity. This is a common enough driver of menopausal fatigue that it warrants checking before assuming the tiredness is purely hormonal.

Iron and perimenopause

During perimenopause, periods often become heavier and more irregular before stopping. This can cause or worsen iron deficiency, and iron deficiency fatigue - which tends to be persistent, physical, and accompanied by breathlessness on exertion - is frequently overlooked as a contributor to perimenopausal tiredness. If periods have been heavier than normal in the years leading up to menopause, iron status is worth checking.

Cortisol and adrenal load

The demands on the HPA axis (stress response system) increase during menopause. Oestrogen normally regulates the cortisol response, and its decline makes the system more reactive. Women who are also managing significant life stressors - which are frequently coinciding with the menopausal transition at this stage of life - often find their fatigue has a strong adrenal or nervous system quality: wired and tired, difficulty switching off, drained by things that used to feel manageable.

Supporting the adrenal and cortisol response is a meaningful intervention here. Adaptogenic herbs - particularly ashwagandha (KSM-66 extract) - have good evidence for reducing cortisol and supporting HPA axis regulation under chronic stress, and several formulations targeting menopausal wellbeing incorporate them alongside nutrients that directly address the hormonal transition.

What helps

Prioritising sleep quality is the most impactful single intervention for menopausal fatigue, given how much of the tiredness is downstream of disrupted sleep. Managing the bedroom environment, reducing alcohol, and consistent sleep timing all make a meaningful difference. Magnesium and Ashwagandha KSM-66 address the hormonal and nervous system contributors to poor sleep rather than just masking the symptom.

Exercise is counterintuitive when you're exhausted, but it's one of the most evidence-supported interventions for menopausal fatigue. It improves mitochondrial function, regulates cortisol, supports sleep quality, and reduces vasomotor symptom frequency. The evidence consistently shows that regular exercisers report lower fatigue severity during menopause than sedentary women, even accounting for other variables.

Checking thyroid function and iron status is worthwhile if fatigue is significant - these are treatable contributors that often go undetected. Adequate vitamin D is similarly worth ensuring, as deficiency compounds fatigue and is extremely common in the UK.

From a supplement perspective, a comprehensive menopause formulation that addresses the hormonal, adaptogenic and nutritional aspects of the transition - alongside magnesium for sleep and Coenzyme Q10 or NMN for cellular energy support - covers the main bases for fatigue that has multiple contributing causes.