Fatigue & Low Energy: Symptoms of Hormonal Imbalance?

Experiencing persistent fatigue or low energy that just won’t shift, no matter how much you sleep or how many coffees you have? You’re not alone. Many women and people with cycles dismiss chronic tiredness as a normal part of a busy life, yet it can be a sign that something is going on. When fatigue becomes persistent, heavy, and impacts your daily life, it’s time to look beyond just needing more rest.

• Fatigue is a feeling of constant tiredness or weakness, and it can be physical, mental, or both. 
• Low energy describes a lack of vigour or motivation. 

Whilst lifestyle factors – like a poor night’s sleep, stress, or a less-than-ideal diet – can certainly cause temporary dips, when these symptoms become chronic, it’s often a signal from your body that your delicate hormonal balance might be disrupted.

This article will explore the common, and often overlooked, hormonal drivers behind feeling tired all the time and outline how taking our Advanced At-Home Hormone and Fertility Test can uncover the root causes of your symptoms.

What Causes Fatigue and Low Energy?

The causes of fatigue are diverse, ranging from simple lifestyle factors to underlying medical conditions. However, many of the most persistent and hard-to-diagnose cases in women often circle back to hormone health.

Common Lifestyle and Medical Causes

Before diving into the hormonal links, it’s important to rule out the most common causes of low energy:

• Sleep Deprivation: Lack of quantity or quality sleep. Sleep disorders like sleep apnoea are common culprits.
• Nutrient Deficiencies: Low levels of iron (leading to anaemia), Vitamin B12, and Vitamin D are strongly associated with fatigue.
• Stress and Mental Health: Chronic stress, anxiety, or depression can deplete both physical and mental reserves.
• Other Medical Conditions: Fatigue is a key symptom of conditions such as coeliac disease, chronic fatigue syndrome (ME/CFS), and heart disease.

The Hormonal Connection: A Deeper Dive

For many, general medical checks come back clear, yet the profound tiredness persists. This is where hormones often step in as the missing piece of the puzzle. Hormones act as chemical messengers throughout the body, regulating metabolism, sleep cycles, stress response, and reproductive health – all of which are intrinsically linked to your energy levels.

How Hormones Affect Fatigue and Low Energy

Several key hormones play critical roles in regulating your energy, and imbalances in any of them can lead to that heavy, constant feeling of being drained.

1. Cycling Hormones (Oestrogen, Progesterone, LH & FSH)

The menstrual cycle is an intricately regulated process driven by the hypothalamic-pituitary-ovarian (HPO) axis. The fluctuation of key hormones – oestrogen (specifically estradiol), progesterone, luteinising hormone (LH) and follicle-stimulating hormone (FSH) – has a significant influence on central nervous system function, affecting energy metabolism, sleep architecture, and neuropsychiatric stability (Li et al., 2020). 

• Oestrogen’s Role: Oestrogen generally acts as a boost; it can be linked to improved muscle function, mood, and sleep quality. When oestrogen peaks in the late follicular phase (leading up to ovulation), many women report feeling their most energetic. A notable dip in oestrogen – such as during the early follicular phase (the start of the cycle/period) or during perimenopause – is often associated with low mood and brain fog.
• Progesterone’s Role: Often called the calming hormone, progesterone rises sharply after ovulation (in the luteal phase). Progesterone has a sedative effect, primarily by enhancing the activity of GABA, the brain’s main inhibitory neurotransmitter. While this is great for promoting sleep, high progesterone during the pre-menstrual (PMS) week can be a key driver of that characteristic fatigue or sluggishness. Poor sleep quality due to a fall in progesterone just before a period can also lead to day-time exhaustion (Ennour-Idrisi et al., 2015).
• LH & FSH: These hormones, released by the pituitary gland, regulate the production of oestrogen and progesterone. While they don’t directly cause fatigue, measuring their levels is crucial for diagnosing reproductive health conditions (like PCOS) or age-related shifts (like perimenopause/menopause), which have fatigue as a key symptom.

2. Androgens (Testosterone, DHEAS & SHBG)

Androgens are essential for vitality in women and people with menstrual cycles. Testosterone and its precursor, DHEAS, are powerful hormones linked to motivation, muscle mass, bone density, and energy metabolism.

• Testosterone’s Impact: A drop in testosterone can lead to decreased muscle mass, lower bone density, reduced libido, and a general sense of low energy (Bolour & Braunstein, 2005). Low testosterone levels often naturally occur with age or can be caused by certain hormonal contraceptives.
• Sex Hormone-Binding Globulin (SHBG): This protein acts as a transport mechanism, binding to sex hormones like testosterone and making them biologically inactive. If your SHBG levels are too high (often seen in high-oestrogen states or with certain medications), it can ‘hoover up’ your biologically active testosterone, leading to low energy and other symptoms, even if your total testosterone level is within the normal range (Szybiak-Skora et al., 2025).

💡 Find out what your hormones are telling you

Take our Advanced At-Home Hormone and Fertility Test to uncover the root causes of your symptoms, including persistent fatigue and low energy.

3. Cortisol (The Stress Hormone)

Cortisol is released by the adrenal glands and is part of the body’s natural “fight or flight” stress response. While essential in short bursts, chronic stress leads to chronically elevated cortisol, which eventually impacts energy regulation (Kumari et al., 2009).

• Chronic Stress and Adrenal Fatigue (Exhaustion): While “adrenal fatigue” isn’t a recognised medical diagnosis, prolonged high stress can lead to dysregulation of the HPA (Hypothalamic-Pituitary-Adrenal) axis, which manages cortisol. This dysregulation is linked to the symptoms of tired all the time and low energy women. Initial high cortisol can disrupt sleep, and later dysregulation can leave you feeling depleted and unable to manage stress.

4. Insulin

Insulin regulates blood sugar, which is your body’s primary fuel source. When insulin is dysregulated (known as insulin resistance), your cells struggle to absorb glucose, leaving your body and brain starved of the energy they need. This common issue is a significant driver of hormonal fatigue and often a core feature of conditions like PCOS.

When to Get Tested

If your fatigue is persistent, severe, and doesn’t improve with rest or lifestyle adjustments, or if you also experience other symptoms such as irregular periods, unexplained weight changes, brain fog, or mood swings, it is a clear sign to investigate your hormone health.

Many hormonal issues, especially early-stage thyroid conditions or sex hormone imbalances, can be missed in routine testing. Getting a comprehensive panel gives you a full picture, moving beyond general blood work to assess the specific hormonal markers that could be causing your low energy.

Consider testing if you:

• Have been consistently tired for three months or more.
• Have tried improving sleep and diet without success.
• Suspect a link between your symptoms and your menstrual cycle (e.g., severe fatigue pre-period).
• Have a family history of thyroid issues or autoimmune conditions.

💡 Find out what your hormones are telling you

Take our Advanced At-Home Hormone and Fertility Test to uncover the root causes of your symptoms, including persistent fatigue and low energy.

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What Your Results Can Tell You

Taking a dedicated hormone and fertility test offers valuable, actionable insights that traditional testing often overlooks. By analysing key hormones, including thyroid hormones, cortisol, and sex hormones (oestrogen, progesterone, testosterone), your results can:

1. Pinpoint Imbalances: Directly identify whether your fatigue is driven by hormonal fluctuations.
2. Uncover Root Causes: Detect underlying conditions such as PCOS, perimenopause or hypothyroidism that have fatigue as a key symptom. Knowing the root cause is the first and most critical step towards effective management and treatment.
3. Guide Management: Provide data to inform a personalised care plan, whether that involves lifestyle changes, targeted nutritional support, or medical interventions, allowing you to move from simply coping with fatigue to actively regaining your energy.

Finding out why you are feeling so tired is empowering. It transforms the symptom from a vague complaint into a clear, treatable medical pathway.

References

• Bolour, S., Braunstein, G. Testosterone therapy in women: a review. Int J Impot Res 17, 399–408 (2005). https://doi.org/10.1038/sj.ijir.390133 
• Ennour-Idrissi, K., Maunsell, E., Diorio, C. (2015). Effect of physical activity on sex hormones in women: a systematic review and meta-analysis of randomized controlled trials. Breast Cancer Res, 17: 2015 https://doi.org/10.14200/jrm.2019.0119 
• Kumari, M., Badrick, E., Chandola, T., Adam, E. K., Stafford, M., Marmot, M. G., Kirschbaum, C., & Kivimaki, M. (2009). Cortisol secretion and fatigue: associations in a community based cohort. Psychoneuroendocrinology, 34(10), 1476–1485. https://doi.org/10.1016/j.psyneuen.2009.05.001 
• Li, S. H., Lloyd, A. R., & Graham, B. M. (2020). Physical and mental fatigue across the menstrual cycle in women with and without generalised anxiety disorder. Hormones and behavior, 118, 104667. https://doi.org/10.1016/j.yhbeh.2019.104667 
• Szybiak-Skora, W., Cyna, W., & Lacka, K. (2025). New Insights in the Diagnostic Potential of Sex Hormone-Binding Globulin (SHBG)-Clinical Approach. Biomedicines, 13(5), 1207. https://doi.org/10.3390/biomedicines13051207