Chronic fatigue syndrome

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Chronic fatigue syndrome (CFS)

Chronic fatigue syndrome (CFS), also known as myalgic encephalomyelitis (ME), is a long-term condition that can drastically affect daily life. It causes extreme tiredness that doesn’t improve with rest and often worsens after physical or mental activity. People living with CFS experience a wide range of symptoms, including problems with thinking, sleep difficulties, muscle and joint pain, and immune system issues. Despite affecting millions worldwide, CFS remains poorly understood and challenging to diagnose and treat.

This blog explores what CFS is, its symptoms, possible causes, and current treatment options. We also highlight innovative therapies available through Courier Pharmacy designed to support those living with this complex condition.

Five key takeaways

• Chronic fatigue syndrome causes severe, lasting tiredness and a range of other symptoms that disrupt daily life.
• The exact cause of CFS is unknown but likely involves a mix of genetic, immune, and environmental factors.
• Diagnosis is difficult due to symptom overlap and lack of specific tests.
• Treatment focuses on managing symptoms, with new compounded  therapies like low dose naltrexone (LDN), melatonin buccal film, and CoQ10 buccal film showing promise.
• Courier Pharmacy offers a unique “Three R” program combining these treatments to help patients Recover energy, Rest better, and Recharge.

What is chronic fatigue syndrome (CFS)?

Chronic fatigue syndrome (CFS) is a complex illness that affects many parts of the body. It causes extreme tiredness that doesn’t go away with rest and often worsens after even minor physical or mental effort. This worsening is called post-exertional malaise (PEM), a key feature that sets CFS apart from ordinary tiredness [1], [2].

People with CFS may also experience:

• Problems with memory, focus, and concentration, often called “brain fog” [2].
• Muscle and joint pain [2].
• Sleep disturbances such as insomnia or unrefreshing sleep [2].
• Flu-like symptoms, headaches, and sore throat [2].
• Symptoms related to the immune system  [1].

CFS can be profoundly disabling, with some patients unable to work or even leave their homes [3].

How common is chronic fatigue syndrome?

Globally, CFS affects between 0.1% and 0.8% of the population, which translates to roughly 17 to 24 million people worldwide  [1], [4]. In the UK, over 250,000 people are estimated to live with CFS, with some areas reporting rates of about 0.2% of the population [5]. Many cases go undiagnosed because of the condition’s complexity and lack of clear diagnostic tests.

What causes chronic fatigue syndrome?

The exact cause of CFS is unknown, but experts believe it results from a combination of genetic and environmental factors  [1]. Common triggers include viral infections (like glandular fever), physical or emotional stress, and exposure to toxins [6], [7], [8].

Genetic factors

Some evidence shows that CFS can run in families, suggesting genes may play a role [9]. However, the specific genes involved remain unclear.

Viral infections

Many people report that their symptoms began after a viral illness, such as Epstein-Barr virus infection [10], [11]. Viruses may trigger immune system changes that contribute to CFS symptoms.

Environmental triggers

Exposure to chemicals, heavy metals, or certain medications can sometimes lead to symptoms similar to CFS [12], [13]. However, vaccines have not been shown to increase CFS risk [14].

What happens in the body with CFS?

CFS affects multiple body systems. Key changes include:

Immune system and inflammation

The immune system may become overactive, causing chronic inflammation and sometimes attacking the body’s own tissues (autoimmunity) [15], [16]. This ongoing inflammation can reduce blood flow and oxygen delivery to muscles and organs, leading to fatigue and pain.

Gut health

Many with CFS have gut issues like bloating and irritable bowel syndrome. Studies show an imbalance in gut bacteria, which may worsen inflammation [17].

Energy production and blood flow

Inflammation and blood vessel changes can reduce oxygen supply to muscles and the brain, making even small activities exhausting [18].

Brain and nerves

Inflammation can affect the brain, causing memory problems, poor concentration, and sleep difficulties [19].

Hormones and blood clotting

Stress hormones may be out of balance, and tiny blood clots might block small vessels, contributing to symptoms [20], [21].

Diagnosing chronic fatigue syndrome

There is no single test for CFS. Diagnosis relies on clinical criteria, such as unexplained fatigue lasting six months or more and other symptoms like PEM, sleep problems, and cognitive issues [22], [2]. Because symptoms overlap with other conditions, diagnosis can take years.

Managing chronic fatigue syndrome: current treatments

There is no cure for CFS, but treatments can help manage symptoms.

Medicines

Common medicines include:

• Painkillers and anti-inflammatories for pain and headaches.
• Anticonvulsants for nerve pain and sleep.
• Antidepressants for mood, sleep, and pain.
• Narcotics for severe pain (short-term use).
• Antivirals and immune-modulating drugs are being researched but are not widely available.

Non-medicine approaches

• Adaptive pacing therapy (APT) helps balance activity and rest.
• Cognitive behavioural therapy (CBT) may help some cope but is not a cure.
• Graded exercise therapy (GET) is controversial and can worsen symptoms for many.

Patient experiences and challenges

Many patients feel misunderstood and face stigma, partly because some doctors don’t recognise CFS as a real illness. The controversy over GET and CBT has caused frustration and anxiety among patients, especially when treatments worsen symptoms or dismiss their experiences [23], [24], [25].

Innovative treatments from Courier Pharmacy: the three R program

Courier Pharmacy offers the unique “Three R” program for ME/CFS, combining three compounded treatments designed to help patients recover, rest, and recharge.

Low Dose Naltrexone (LDN)

LDN may help reduce fatigue, pain, and inflammation by balancing the immune system. A retrospective study of 218 patients showed about 70% reported symptom improvements with LDN [26].

Melatonin buccal film

Melatonin supports sleep and may reduce fatigue [27]. Courier Pharmacy’s melatonin buccal film is absorbed through the mouth lining for better uptake. It is available only after completing the ME/CFS questionnaire to ensure safe use.

Coenzyme Q10 (CoQ10) 50mg buccal film

CoQ10 helps produce energy and improve quality of life in those people with chronic fatigue syndrome [28]. It also behaves as an antioxidant and helps to protect cells but is poorly absorbed in standard pills. Courier Pharmacy’s CoQ10 buccal film dissolves in the cheek for faster, more efficient absorption, improving energy support.

By combining these three therapies, the Three R program offers a comprehensive, science-backed approach to managing CFS symptoms. This program is the first of its kind available in the UK and is tailored to support patients’ unique needs.

Looking to the future

Research continues to explore the causes and treatments of CFS, including genetics, immune function, and new technologies. The goal is to develop better tests and personalised therapies to improve patient outcomes.

References:

1. Arron, H.E., Marsh, B.D., Kell, D.B., Khan, M.A., Jaeger, B.R. and Pretorius, E., 2024. Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: the biology of a neglected disease. Frontiers in Immunology, 15, p.1386607.
2. Chronic fatigue syndrome (CFS). Available at: https://www.nhs.uk/conditions/chronic-fatigue-syndrome-cfs/ (Accessed: 21 October 2025).
3. Lim, E.J. and Son, C.G., 2020. Review of case definitions for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Journal of translational medicine, 18(1), p.289.
4. Lim, E.J. and Son, C.G., 2020. Review of case definitions for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Journal of translational medicine, 18(1), p.289.
5. Nacul, L.C., Lacerda, E.M., Pheby, D., Campion, P., Molokhia, M., Fayyaz, S., Leite, J.C., Poland, F., Howe, A. and Drachler, M.L., 2011. Prevalence of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) in three regions of England: a repeated cross-sectional study in primary care. BMC medicine, 9(1), p.91.
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8. Behan, P.O., 1996. Chronic fatigue syndrome as a delayed reaction to chronic low-dose organophosphate exposure. Journal of Nutritional & Environmental Medicine, 6(4), pp.341-350.
9. Underhill, R.A. and O’gorman, R., 2006. Prevalence of chronic fatigue syndrome and chronic fatigue within families of CFS patients. Journal of Chronic Fatigue Syndrome, 13(1), pp.3-13.
10. Lerner, A.M., Ariza, M.E., Williams, M., Jason, L., Beqaj, S., Fitzgerald, J.T., Lemeshow, S. and Glaser, R., 2012. Antibody to Epstein-Barr virus deoxyuridine triphosphate nucleotidohydrolase and deoxyribonucleotide polymerase in a chronic fatigue syndrome subset. PloS one, 7(11), p.e47891.
11. Blomberg, J., Gottfries, C.G., Elfaitouri, A., Rizwan, M. and Rosén, A., 2018. Infection elicited autoimmunity and myalgic encephalomyelitis/chronic fatigue syndrome: an explanatory model. Frontiers in immunology, 9, p.229.
12. Behan, P.O., 1996. Chronic fatigue syndrome as a delayed reaction to chronic low-dose organophosphate exposure. Journal of Nutritional & Environmental Medicine, 6(4), pp.341-350.
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15. Proal, A. and Marshall, T., 2018. Myalgic encephalomyelitis/chronic fatigue syndrome in the era of the human microbiome: persistent pathogens drive chronic symptoms by interfering with host metabolism, gene expression, and immunity. Frontiers in pediatrics, 6, p.373.
16. Sotzny, F., Blanco, J., Capelli, E., Castro-Marrero, J., Steiner, S., Murovska, M. and Scheibenbogen, C., 2018. Myalgic encephalomyelitis/chronic fatigue syndrome–evidence for an autoimmune disease. Autoimmunity reviews, 17(6), pp.601-609.
17. Newberry, F., Hsieh, S.Y., Wileman, T. and Carding, S.R., 2018. Does the microbiome and virome contribute to myalgic encephalomyelitis/chronic fatigue syndrome?. Clinical Science, 132(5), pp.523-542.
18. Fluge, Ø., Tronstad, K.J. and Mella, O., 2021. Pathomechanisms and possible interventions in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). The Journal of Clinical Investigation, 131(14).
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21. Hannan, K.L., Berg, D.E., Baumzweiger, W., Harrison, H.H., Berg, L.H., Ramirez, R. and Nichols, D., 2000. Activation of the coagulation system in Gulf War Illness: a potential pathophysiologic link with chronic fatigue syndrome A laboratory approach to diagnosis. Blood coagulation & fibrinolysis, 11(7), pp.673-678.
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26. Polo, O., Pesonen, P. and Tuominen, E., 2019. Low-dose naltrexone in the treatment of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). Fatigue: Biomedicine, health & behavior, 7(4), pp.207-217.
27. Castro-Marrero, J., Zaragozá, M.C., López-Vílchez, I., Galmés, J.L., Cordobilla, B., Maurel, S., Domingo, J.C. and Alegre-Martín, J., 2021. Effect of melatonin plus zinc supplementation on fatigue perception in myalgic encephalomyelitis/chronic fatigue syndrome: a randomized, double-blind, placebo-controlled trial. Antioxidants, 10(7), p.1010.
28. Vitetta, L., Leong, A., Zhou, J., Dal Forno, S., Hall, S. and Rutolo, D., 2018. The plasma bioavailability of coenzyme Q10 absorbed from the gut and the oral mucosa. Journal of Functional Biomaterials, 9(4), p.73.