Why Am I Always Tired?

Why Am I Always Tired? A Deep Dive into Chronic Fatigue, Mitochondria, and Root-Cause Solutions

Feeling exhausted all the time is more than just an inconvenience—it’s a warning sign. If you find yourself constantly asking, “Why am I always tired?” despite rest, clean eating, and doing “all the right things,” you’re not alone—and you’re not crazy.

Persistent fatigue can signal an underlying imbalance, one that’s often misunderstood or missed entirely in conventional medicine. Let’s break it down using the latest research and a root-cause, functional medicine lens.

What Is Chronic Fatigue?

Chronic Fatigue Syndrome (CFS)—also known as Myalgic Encephalomyelitis (ME)—is a complex condition marked by unexplained, persistent fatigue lasting 6 months or more that isn’t relieved by rest. It affects millions globally and is often accompanied by:

• Brain fog.

• Muscle or joint pain.

• Sleep disturbances.

• Dizziness.

• Post-exertional malaise (feeling worse after physical or mental activity).

But even if you don’t meet the full CFS criteria, many of these symptoms may reflect early stages of bioenergetic dysfunction.

The Bioenergetic Model of Fatigue: Where Energy Really Comes From

Every cell in your body (except red blood cells) contains mitochondria. These tiny structures are responsible for converting the food you eat into ATP (adenosine triphosphate), the currency of energy used by all cellular processes. But ATP is not just about physical stamina; it powers:

• Brain function and memory.
• Hormone synthesis.
• Immune regulation.
• Detoxification.
• Cellular repair and regeneration (including regenerating the gut lining!)

When ATP production falters, these systems begin to fail. Over time, this shows up as:

• Chronic fatigue.
• Brain fog.
• Hormonal imbalance.
• Poor recovery from stress or illness.
• Inflammatory conditions and accelerated aging.
• Chronic gut issues.

You don’t just feel tired. You feel like your whole system is running on empty.

Bioenergetics Explained

Bioenergetics is the study of how your body converts food into usable energy. It involves digestion, nutrient transport, blood sugar regulation, oxygen delivery, mitochondrial dynamics, and waste clearance. If any of these systems are impaired, your energy drops.

Key players in bioenergetics include:

• Fuel Sources: Glucose and ketones provide raw material for energy.
• Mitochondria: Convert these fuels into ATP through oxidative phosphorylation.
• Oxygen: Delivered via red blood cells, it’s essential for efficient energy production.
• Antioxidants: Neutralise the free radicals created during ATP synthesis.
• Micronutrients: Co-factors like B vitamins, l-carnitine, magnesium, and CoQ10 are vital for mitochondrial enzymes.
• Hormones: Thyroid, estrogen, testosterone, and cortisol regulate mitochondrial function.
• Sleep and Circadian Rhythm: Align your body clock with mitochondrial activity.
• The Microbiome: Gut bacteria influence energy metabolism and inflammation via bacterial metabolites such as butyrate.

This is not a “one-issue” model. Fatigue is multifactorial, and bioenergetics gives us a map.

Spoiler alert: A product we mention below that provides several key nutrients for mitochondrial function is Mitochondrial Cofactors. Key Root Causes of Fatigue You Shouldn’t Ignore

Now we know what mitochondria require for optimal energy production, you can likely already name some common causes of mitochondrial dysfunction.

1. The Gut Microbiome

In recent years, scientists have been exploring how the gut microbiome—the community of microorganisms living in our digestive tract—might be altered in individuals with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS), and what that could mean for patients.

What they’ve found is compelling. People with ME/CFS often have significant imbalances in their gut bacteria compared to healthy individuals. These changes, known as dysbiosis, affect not just the gut, but also the microbiome of the saliva and feces—linking microbial imbalance to the disease itself.

In several studies using advanced techniques like 16S rRNA sequencing to analyse stool samples, researchers have consistently observed reduced microbial diversity and altered bacterial composition in ME/CFS patients. One of the most striking findings is a drop in the population and diversity of Firmicutes, a group of bacteria generally associated with gut health, alongside an increase in Bacteroidetes. These shifts in the balance of bacterial groups mirror patterns seen in other autoimmune diseases such as Crohn’s disease, lupus, and type 2 diabetes, suggesting a potential connection between gut microbes and immune system dysfunction in ME/CFS.

In many cases, these microbial changes also include a rise in Enterobacteriaceae, a family of bacteria often linked to inflammation. Together, these patterns point to a complete reshuffling of the gut ecosystem in ME/CFS, which may help explain both digestive and immune-related symptoms.

It’s important to note that many factors can influence the microbiome, including diet, genetics, and environment—even geography. That’s why studies that compare people with ME/CFS to closely matched healthy individuals are essential. For example, one study found different gut microbial profiles in ME/CFS patients with and without IBS (Irritable Bowel Syndrome), a common comorbidity. Those with IBS tended to have increased levels of Alistipes and decreased Faecalibacterium, while those without IBS showed increases in certain Bacteroides species (excluding B. vulgatus). These differences highlight the complexity of the condition and underscore the need for larger, more diverse studies to confirm these findings.

Beyond microbial composition, dysbiosis in ME/CFS may also contribute to gut inflammation and increased intestinal permeability—commonly referred to as a “leaky gut.” In fact, some studies have found evidence of bacterial translocation, where bacteria or their components, like lipopolysaccharide (LPS), move from the gut into the bloodstream. LPS is a known trigger for inflammation, and elevated levels in ME/CFS patients suggest a link between dysbiosis, inflammation, and symptom severity.

While the exact mechanisms remain unclear, one leading theory is that the overgrowth of inflammatory bacteria like Enterobacteriaceae contributes directly to gut lining damage and immune activation. There’s also interest in whether bacterial byproducts might interfere with hormone receptors, such as the estrogen and vitamin D receptors, both of which are connected to immune regulation. This is particularly relevant given the high rates of autoimmune conditions seen alongside ME/CFS, though much more research is needed in this area.

Finally, we cannot ignore the gut-brain connection. The gut-brain axis, which links the digestive system to the nervous system, may help explain how microbial changes in the gut influence not just physical symptoms, but also neurological and cognitive issues experienced by many ME/CFS patients. The autonomic and enteric nervous systems are likely involved in this process, suggesting that gut health may play a far greater role in ME/CFS than previously appreciated.

While we’re still unraveling the details, targeting the gut microbiome represents a promising area for future therapies—one that could improve both gastrointestinal and systemic symptoms. More high-quality, large-scale research is needed to validate these early discoveries and move toward personalised treatment strategies based on gut health.

Discover the reasons for your gut symptoms.

View our gut health tests

2. Leaky Gut

The gut is more than just a digestive organ—it plays a critical role in overall health. The intestinal lining, made up of a single layer of tightly connected cells, acts like a selective filter. It allows important nutrients and water to pass through while keeping harmful substances like bacteria and toxins out of the bloodstream.

In a healthy gut, these cells are held together by specialized structures (tight junctions) made of proteins like occludin and claudins. But when the gut is under stress—due to inflammation, an imbalance of gut bacteria (dysbiosis), long-term use of NSAIDs, or even chronic stress—this protective barrier can become “leaky.” This condition, often referred to as leaky gut, allows unwanted bacteria and toxins to enter the bloodstream.

One of the most concerning consequences of a leaky gut is the movement of a bacterial toxin called lipopolysaccharide (LPS) into the blood. This triggers the immune system, leading to chronic low-grade inflammation, a state known as metabolic endotoxemia. Over time, this persistent immune activation can contribute to a variety of health problems.

Research shows that this process may play a key role in diseases like obesity, diabetes, non-alcoholic fatty liver disease, atherosclerosis, and ME/CFS (Myalgic Encephalomyelitis/Chronic Fatigue Syndrome). In people with ME/CFS, studies have found elevated levels of immune responses to LPS and gut bacteria, and these levels often correlate with the severity of symptoms. This suggests that a leaky gut may be a significant contributor to the disease process.

Encouragingly, targeting gut health through dietary changes and anti-inflammatory supplements has shown promising results. In some cases, patients experienced symptom relief when these approaches were combined. Similar findings have been reported in individuals with depression, pointing to shared mechanisms involving gut health and brain function.

We also know that neuroinflammation—inflammation in the brain—is a common feature of many chronic illnesses, including ME/CFS. Because substances that leak from the gut can promote systemic inflammation, some researchers believe they may also disrupt the blood-brain barrier, leading to changes in brain function and contributing to the cognitive symptoms seen in ME/CFS. While this theory is compelling, more research is needed to confirm it.

There’s also growing interest in the possibility that ME/CFS has autoimmune features. A viral infection may trigger gut dysbiosis and immune dysfunction in genetically predisposed individuals, potentially leading to the body mistakenly attacking its own tissues. Again, gut permeability and bacterial translocation appear to play a role in this autoimmune-like response.

Overall, what emerges is a complex relationship between the gut, immune system, and brain. When the gut barrier breaks down, it sets off a chain reaction: inflammation rises, healthy gut bacteria decline, and harmful bacteria thrive—especially those from the Enterobacteriaceae family. This shift reduces the production of beneficial short-chain fatty acids (SCFAs), which are vital for gut and brain health. As a result, both the gut and the brain may become inflamed, contributing to the symptoms of ME/CFS.

As an expert in this field, I believe that therapies aimed at restoring gut integrity and balance (known as eubiosis) offer a promising new direction. These may include prebiotics, probiotics, and targeted dietary strategies. While the early results are encouraging, we still need more rigorous studies to fully understand their potential and effectiveness in ME/CFS and related conditions.

Discover the reasons for your gut symptoms.

View our gut health tests

3. Nutrient Deficiencies

Even with a healthy diet, poor absorption and high demand from chronic stress or illness can lead to deficits. It’s important to stress that ideally supplementation would be based on functional test results so you know precisely what nutrients are required to optimise mitochondrial function. Having said that, there are some that research has shown can generally be helpful including:

Magnesium

While I haven’t been able to find any randomised control trials on magnesium for CFS, we know that magnesium plays a central role in energy production at the cellular level, which is why a deficiency can leave you feeling constantly drained. This essential mineral is required for the activation of adenosine triphosphate (ATP), the molecule that delivers energy to nearly every cell in your body. Without enough magnesium, your mitochondria—your cells’ power plants—struggle to generate ATP efficiently. This means your body literally can’t produce or access the energy it needs to function optimally, resulting in fatigue, brain fog, and muscle weakness.

Chronic stress, poor diet, and certain medications can deplete magnesium levels, making it a frequently overlooked but critical factor in persistent tiredness.

Recommend product: Magnesium Biglycinate

CoQ10

A recent high-quality clinical trial (source) has brought encouraging news for people living with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS). In this 12-week randomised, double-blind, placebo-controlled study—the gold standard in clinical research—scientists evaluated the effects of a daily supplement combining Coenzyme Q10 (CoQ10) and NADH, two natural compounds involved in cellular energy production.

The trial involved 207 patients with ME/CFS, who were randomly assigned to take either the active supplement (200 mg CoQ10 and 20 mg NADH) or a placebo, once a day. Patients were assessed at the beginning of the study, then again at 4 weeks, 8 weeks, and 4 weeks after stopping treatment, using well-established tools that measure symptoms like fatigue, sleep, and quality of life.

The results were promising. Patients who took the CoQ10 + NADH supplement reported a significant reduction in cognitive fatigue—the kind of mental exhaustion that many ME/CFS patients struggle with daily. They also showed overall improvements in fatigue symptoms (as measured by the FIS-40 scale) and a better quality of life (according to the SF-36 health questionnaire).

Interestingly, the supplement group also experienced better sleep outcomes, including longer sleep duration after 4 weeks, and improved sleep efficiency after 8 weeks, compared to their own baseline measurements.

As an expert in the field, I find these findings particularly encouraging because they offer evidence that this combination therapy may be both effective and safe in helping to manage some of the most debilitating symptoms of ME/CFS—especially fatigue and poor sleep, which often go hand-in-hand.

Recommended product: CoQ10, or, a nice product that contains CoQ10, NADH, acetyl-l-carnitine and vitamins B12 and B6 is Mitochondrial Cofactors. As you can see we discuss all of these within the blog.

B-vitamins.

A recent randomised, double-blind, placebo-controlled crossover study (source) explored whether high-dose thiamine (vitamin B1) could help relieve this fatigue—and the results were promising.

The study involved 40 patients with quiescent (inactive) IBD who were also experiencing severe, unexplained chronic fatigue. Participants received either high-dose oral thiamine (600–1800 mg/day) or a placebo for four weeks, followed by a four-week washout period, and then switched to the other treatment. This crossover design allowed each participant to serve as their own control, improving the reliability of the findings.

Fatigue levels were tracked using a specialised questionnaire designed for people with IBD. The main goal was to see how many patients experienced a clinically meaningful improvement—defined as a reduction of 3 or more points in their fatigue score after taking thiamine.

The results were clear:

Patients reported a significant average reduction in fatigue while taking thiamine (a drop of 4.5 points), compared to a slight increase in fatigue on placebo.

More than half of the participants improved while taking thiamine (55% in one group and 75% in the other), compared to just 25–35% while on placebo.

No serious side effects were reported—only mild ones—suggesting the treatment is well tolerated.

I find these results encouraging. They suggest that high-dose thiamine may be a simple, safe, and effective way to reduce fatigue in people with IBD, especially when no other medical explanation for their fatigue is found.

B vitamins generally are the unsung heroes of energy metabolism. Acting as coenzymes, B1 (thiamine), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6, B9 (folate), and B12 are all essential for converting carbohydrates, fats, and proteins into ATP—the energy currency of your cells. Deficiencies in any of these can impair cellular energy production and lead to symptoms like tiredness, irritability, poor concentration, and even mood imbalances.

Vitamin B12 and folate, in particular, are critical for red blood cell formation, which helps transport oxygen throughout the body—a vital process for sustaining energy.

Recommended product: B Complex Plus

L-carnitine

Carnitine is an amino-acid-like nutrient that plays a pivotal role in fat metabolism by transporting long-chain fatty acids into the mitochondria, where they’re burned for energy. Without enough carnitine, your body struggles to access fat stores efficiently—one of your most abundant energy sources. This can result in sluggishness, poor endurance, and even muscle fatigue.

A recent study offers new hope in the form of a natural compound called Acetyl L-Carnitine (ALCAR). Amantadine is one of the most commonly prescribed medications for MS-related fatigue, its effectiveness varies—and side effects can be a concern. In this randomised, double-blind, crossover trial, researchers compared ALCAR (1,000 mg twice daily) with amantadine (100 mg twice daily) in 36 patients with MS-related fatigue. Each patient received one treatment for three months, followed by a three-month washout, and then switched to the other treatment for another three months.

• The main outcome measure was the Fatigue Severity Scale (FSS), a well-validated tool for assessing fatigue in MS. The results were clear:
• ALCAR was significantly more effective than amantadine at reducing fatigue (p = 0.039).
  Fewer side effects were reported with ALCAR—only one patient dropped out due to side effects, compared to five on amantadine.
• There were no significant differences in depression or social functioning, indicating that the key benefit of ALCAR was directly related to physical fatigue reduction.

Recommended product: Acetyl-L-Carnitine

Iron

Iron is fundamental to maintaining your energy levels because it’s a key component of heamoglobin, the protein in red blood cells that transports oxygen from your lungs to your tissues. Without enough iron, your cells are starved of oxygen, and the result is often a deep, physical fatigue—commonly described as feeling “wiped out” or short of breath. Iron deficiency is especially common in menstruating women, athletes, and people with digestive issues that impair absorption.

Even low-normal levels of iron can lead to fatigue, making it essential to assess and optimise iron status when energy is low.

In my clinical practice it is rare to see clients with iron deficiency anaemia but it is one of the first things to rule out.

Recommended product (if required!): Iron-C

Copper

Copper often flies under the radar, but it’s absolutely crucial for energy production and iron metabolism. It works as a cofactor for enzymes involved in the electron transport chain, where ATP is generated in the mitochondria. Additionally, copper is required to help transport and utilise iron properly. Without adequate copper, you may experience similar symptoms to iron deficiency—fatigue, weakness, and poor concentration—even if your iron levels appear normal.

This is especially relevant for individuals taking high-dose zinc supplements, which can deplete copper over time.

Recommended product: Zinc & Copper

4. Hormonal Dysregulation

Hormonal dysfunction—particularly involving the hypothalamic-pituitary-adrenal (HPA) axis—has been consistently observed in people with ME/CFS. Many patients exhibit blunted cortisol output, altered diurnal rhythm, or a reduced ability to mount a stress response, which may contribute to symptoms like severe fatigue, sleep disturbances, poor stress tolerance, and cognitive fog. Dysregulation of other hormones, including thyroid hormones, DHEA, aldosterone, and even sex hormones (like estrogen and testosterone), can also be seen in subsets of patients. These imbalances may impair energy metabolism, worsen autonomic dysfunction, and contribute to the wide variability of symptoms experienced in ME/CFS. Clues that hormonal dysfunction could be a factor include orthostatic intolerance, temperature sensitivity, unrefreshing sleep, libido changes, and exacerbation of symptoms around hormonal shifts (such as menstruation or menopause).

5. Chronic Infections

Epstein-Barr Virus (EBV)

Infections—particularly viral ones—are well-established as potential triggers and perpetuating factors in ME/CFS (source). Viruses like Epstein-Barr Virus (EBV), human herpesvirus 6 (HHV-6), cytomegalovirus (CMV), and even enteroviruses have been linked to ME/CFS onset in a subset of patients. These pathogens may contribute to chronic immune activation, mitochondrial dysfunction, and neuroinflammation, even after the initial infection has resolved. Symptoms that may suggest an infectious component include sore throat, swollen lymph nodes, low-grade fevers, post-exertional malaise, and a flu-like feeling that lingers long after the acute phase. In some cases, patients report that their ME/CFS began abruptly following a viral illness, which supports the theory that a dysregulated immune response to infection, rather than the infection itself, may be driving ongoing symptoms.

Blood work, specifically white blood cells, can shed light on whether an infection might be at play.

6. Environmental Toxins (e.g., Mycotoxins or/and Heavy Metals)

Several studies have reported that patients diagnosed with ME/CFS frequently carry mycotoxins—toxins produced by moulds like Aspergillus—in their urine. In one (source) patients with chronic fatigue and known exposure to water-damaged buildings, over 90% had detectable levels of toxins such as ochratoxin A, aflatoxin, or trichothecenes, even when the exposure occurred years earlier.

A larger prevalence study involving 236 ME/CFS patients with histories of mould exposure found 92.4% had mycotoxin biomarkers, with ochratoxin A being most common (source).

These studies suggest that long-term internal reservoirs—such as sinus biofilms—might continue releasing toxins for years after initial exposure, potentially contributing to persistent symptoms through mitochondrial dysfunction, oxidative stress, and immune activation.

Though direct studies of heavy metal levels in ME/CFS cohorts are limited, heavy metals such as cadmium, mercury, nickel, and gold have been implicated in fatigue, immune dysregulation, and neuropathology:

A hypothesis-driven paper proposed that cadmium exposure may contribute to neurological symptoms in ME/CFS—such as reduced gray matter volume, impaired attention and memory—based on cadmium’s known neurotoxicity and its impact on cerebral blood flow and angiogenesis (source).

A small clinical series using MELISA lymphocyte transformation testing found that many patients with chronic fatigue (and autoimmune thyroid disease) were hypersensitive to metals—especially mercury and nickel—and that removal of dental metal restorations led to improvement in symptoms (source).

Heavy metals may bind to mitochondrial enzymes, trigger oxidative stress, and promote inflammatory immune responses—mechanisms also identified in ME/CFS pathophysiology

Integrated Mechanisms

Reviews of ME/CFS biology emphasise that environmental exposures (including moulds, organophosphates, pesticides, heavy metals, and even low-level radiation) may act in concert with immune, neuro-oxidative, and mitochondrial pathways to perpetuate chronic illness. Thus, toxins may be among several triggers or perpetuating factors rather than sole causes.

What You Can Do: A Functional Medicine Roadmap for Fatigue

1. Run the Right Labs

Don’t rely on surface-level blood work. Consider:

• Mitochondrial function panels.

• Organic acid tests (OAT).

• EBV and viral titers.

• Stool and SIBO testing.

• Mycotoxin and heavy metal testing.

• Full thyroid panel (TSH, Free T3, Free T4, reverse T3, antibodies).

• Cortisol salivary test, or DUTCH testing.

2. Nourish Your Mitochondria

In a great paper entitled Nutrition, Bioenergetics and Metabolic Syndrome the authors discussed the importance of mono- and polyunsaturated fatty acids, vitamins A, B, C, D and E, selenium, zinc, olive oil, polyphenols such as resveratrol (from things like grapes), organosulfured compounds (like garlic) and catechins (from green tea). Ultimately a whole food nutrient dense diet that limits refined sugar and processed foods is going to support mitochondrial function and gut microbiome health. There are times, the more extreme cases, where are ketogenic diet may be of value too.

3. Support Gut Health

Supporting gut health will depend on the exact issues but the first consideration should be around optimising the digestive process itself. In my experience many suffering with chronic fatigue have low stomach acid that can contribute to poor digestion, SIBO, and IBS like symptoms. This is not surprising considering that the production of stomach acid is a very energy intensive process.

This begs the question, do those with CFS/ME have gut issues because of a lack of cellular energy within the cells that create stomach acid – the parietal cells.

4. Support Gentle Detox

Now is not the time to get deep in to detoxification but when detoxification is needed start with dietary and lifestyle changes. It’s important you are having at least one well formed bowel movement per day before starting supporting detox. And go slow – more is never better.

• Support liver pathways with cruciferous vegetables, and bitter foods such as wild rocket, dandelion, dark chocolate and cruciferous vegetables. Detox is dependent on a long list of nutrients including B vitamins, antioxidants and amino acids such as glycine.

• Infrared sauna, lymphatic drainage, dry brushing.

• Air purifiers and dehumidifiers will also be important if still living in mould-prone environments.

Again the liver is a very energy consuming organ and so supporting mitochondrial health may actually lay the foundation for better detoxification capacity too.

5. Balance the Nervous System

This ultimately is the first priority as a regulated nervous system is foundational to healing. I am a huge advocate for nervous system healing and polyvagal informed practice.

You can also consider adaptogens like Rhodiola, Ashwagandha, and Korean Ginseng.

Final Thoughts On Why I Am Always Tired

Chronic fatigue is not “all in your head.” It’s often a multi-layered condition involving mitochondrial dysfunction, gut imbalances, infections, hormonal imbalances, toxic burden, and nutrient depletion. The good news? These imbalances are reversible with a root-cause approach.

But a logical, systematic, layered approach is often needed. You can’t do everything at once, and so the question becomes where do we start. And unfortunately that is going to be unique for each person dependent on their current state. But know there is a solution and working with an experienced practitioner in this field can take the guess work and overwhelm out of the equation.

You don’t have to accept exhaustion as your new normal.