Chronic Fatigue Syndrome and CBD: The Research

For someone living with chronic fatigue syndrome, fatigue is not ordinary tiredness that a good night's sleep fixes; sometimes even taking a shower or a short walk can trigger a crash that lasts for days. When you are dealing with an illness whose cause is not fully known and that is hard to treat, it is very natural to look into new options. In this article, we explain in plain language what chronic fatigue syndrome is, what we know and don't yet know about CBD, the possible side effects, and topics you can discuss with your doctor.

What is chronic fatigue syndrome?

Chronic fatigue syndrome, also known in medicine as myalgic encephalomyelitis or ME/CFS for short, is a long-term illness that can affect different systems of the body. According to the UK's National Health Service (NHS), its four main symptoms are:

• Constant, extreme tiredness that makes even daily tasks hard,
• Sleep problems such as insomnia, sleeping too much, or waking up feeling unrefreshed and stiff,
• Trouble thinking, concentrating and remembering (brain fog),
• Symptoms getting worse after physical or mental effort, with recovery sometimes taking weeks (post-exertional malaise).

Some people also have pain in different parts of the body, headaches, joint and muscle pain, or flu-like symptoms. The cause is unknown, and there is no single test for the illness; diagnosis is based on the symptoms and on ruling out other conditions that can cause similar symptoms (NHS).

There is not yet a cure for ME/CFS, but there are approaches that help people cope with the symptoms: energy management, which teaches how to use energy without making symptoms worse; cognitive behavioral therapy; and medicines a doctor considers suitable for pain or sleep problems (NHS). England's national health guideline also offers detailed recommendations for diagnosis, support and symptom management (NICE 2021). An assessment prepared by specialist physicians stresses that graded exercise programs, in which activity is gradually increased, are no longer recommended as a first choice (Bateman 2021).

Why are people curious about CBD?

CBD (cannabidiol) is a substance found in the cannabis plant that, unlike THC, does not make you high or cloud your thinking. Because it is linked to the endocannabinoid system, which helps the body regulate pain, sleep and the stress response, it is being studied for pain and sleep.

Chronic fatigue syndrome shares some features with fibromyalgia in terms of widespread pain, fatigue and sleep problems. Some researchers have suggested that the endocannabinoid system may not be working well enough in conditions such as fibromyalgia, migraine and irritable bowel syndrome (Russo 2016). However, this is a hypothesis, and it has not been examined separately in chronic fatigue syndrome.

What does the research say?

In chronic fatigue syndrome: no studies yet

We found no human study of CBD or cannabis in chronic fatigue syndrome looking at its benefits or harms. This does not mean that CBD doesn't work; it only shows that the research to answer this question has not been done yet.

What is known from related conditions

• Fibromyalgia and pure CBD: In a 24-week controlled study of 200 patients, 50 mg of pure CBD a day did not reduce pain more than placebo (Rasmussen 2026). Details are in our article on fibromyalgia and CBD.
• Fibromyalgia and oil containing THC: In a 24-person pilot study of an oil containing equal amounts of THC and CBD, positive signs were seen for pain and sleep; there was no clear change in fatigue, however (Kurlyandchik 2026).
• Sleep: In an analysis combining controlled studies, products containing only CBD did not improve sleep quality clearly differently from placebo; a clearer effect was seen with products containing THC (da Silva 2025). Details are on the sleep page.
• Long-lasting pain: In 15 of 16 controlled studies of pure CBD for pain, CBD was not found to be better than placebo (Moore 2024).

Possible side effects and drug interactions

For someone with chronic fatigue syndrome, the most important point is this: fatigue and sleepiness are among CBD's most common side effects.

• Fatigue and sleepiness: In the epilepsy studies of the approved CBD medicine, sleepiness was one of the most common side effects; weakness and exhaustion were also more common in those taking CBD (11–12% vs. 4% with placebo) (FDA Epidiolex label). These high doses are not the same as products on the market, but the direction matters. In a review pooling clinical studies, fatigue was also among the most commonly reported side effects (Iffland 2017).
• Liver: In a 4-week study of healthy adults, liver enzymes rose markedly in 5.6% of those taking 5 mg of CBD per kilogram of body weight a day (Florian 2025).
• Drug interactions: CBD can slow down how the body breaks down some medicines. Together with sleeping pills, sedatives and some medicines used for pain, sleepiness and drowsiness may increase; a single dose of CBD somewhat raised blood levels of amitriptyline, which is also used for pain and sleep (Gorbenko 2026). You can look up your own medicine on the drug interactions page.

How was it used in studies?

Because CBD has not been tested in chronic fatigue syndrome, there is no study dose. In the fibromyalgia study, 50 mg of pure CBD a day was used for 24 weeks (a study dose, not a personal recommendation), and no clear difference from placebo was seen for pain.

If you are thinking about using CBD

If you have felt drained for a long time, it is very understandable to want to consider every option that offers hope. You can talk with your doctor about:

• Whether your fatigue has another cause (for example, checking for conditions such as anemia or thyroid problems).
• Energy management and planning daily activities without making symptoms worse.
• All the medicines you take, especially sleeping pills, sedatives, antidepressants and pain relievers.
• That CBD can cause fatigue and sleepiness, and how you would track your symptoms if you try it.
• Your liver health; pregnancy or breastfeeding.

Do not reduce or stop your prescription medicine on your own. In Turkey, cannabis-derived products, including CBD, may be sold only in pharmacies (Law No. 7557; regulation of January 31, 2026). Those classed as medicines or health products are dispensed with a prescription; the regulation does not state a prescription requirement for supplement products with a THC content of at most 0.3%. As of October 2026, there is no approved (licensed) CBD medicine in Turkey. For details, see our regulations page.

Conclusion

The effect of CBD in chronic fatigue syndrome has not yet been studied; in related conditions, there was no clear difference in pain with pure CBD, or in fatigue with an oil containing THC. What's more, fatigue and sleepiness are among CBD's known side effects. For this illness, energy management and symptom treatment planned with your doctor are the soundest path today; if you are curious about CBD, you can bring that into the conversation too.

Frequently asked questions

References