ME/CFS Evidence Browser — Classified Studies on Myalgic Encephalomyelitis

21–40 of 206 studies

Does oral coenzyme Q10 plus NADH supplementation improve fatigue and biochemical parameters in chronic fatigue syndrome?

Castro-Marrero, Jesús, Cordero, Mario D, Segundo, María José et al.·Antioxidants & redox signaling·2015

This 8-week study tested whether taking two supplements—coenzyme Q10 and NADH—could reduce fatigue in people with ME/CFS. Seventy-three Spanish patients received either the supplements or a placebo. The group taking the supplements reported less fatigue and showed improvements in blood markers related to energy production and oxidative stress compared to the placebo group.

Energy Metabolism

E1 ReplicatedTrialPEM not requiredRCT

Amantadine and L-carnitine treatment of Chronic Fatigue Syndrome.

Plioplys, A V, Plioplys, S·Neuropsychobiology·1997

This study tested whether two medicines—L-carnitine and amantadine—could help reduce fatigue in ME/CFS patients. Researchers gave 30 patients each medicine for 2 months to compare which worked better. L-carnitine was well-tolerated and showed improvement in most measured symptoms, while amantadine caused side effects that forced half the patients to stop taking it.

Energy Metabolism

E1 ReplicatedTrialPEM unclearRCT

Chronic fatigue syndrome and chronic primary magnesium deficiency (CFS and CPMD).

Durlach, J·Magnesium research·1992

This study explored whether people with chronic fatigue syndrome (ME/CFS) might have low magnesium levels in their bodies. Magnesium is a mineral that helps muscles and nerves work properly. The researcher examined the connection between magnesium deficiency and ME/CFS symptoms to understand if treating low magnesium could help patients feel better.

Energy Metabolism

E2 ModerateCohortPEM unclearCross-Sectional

Plasma Extracellular Vesicle Surface Marker Profiling Reveals Immune Cell-Associated Mitochondrial Membrane Potential Alterations in Long COVID and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Ikeda, Gentaro, Koike-Ieki, Mariko, Inoue, Hiroyuki et al.·Open forum infectious diseases·2026

Researchers analyzed tiny cell particles called extracellular vesicles in blood samples from people with Long COVID, ME/CFS, and healthy controls. They observed that both Long COVID and ME/CFS groups had elevated levels of certain immune cell-derived particles and alterations in mitochondrial (energy-producing) markers within B cells and other immune cells, though the findings were not identical between groups. These preliminary results suggest there may be shared immune and metabolic changes in these conditions, but the meaning of these changes for patient health remains unclear and needs further study.

BiomarkersEnergy MetabolismImmune SystemLong COVID Overlap

E2 ModerateCohortPEM not requiredCross-Sectional

Increased galanin-galanin receptor 1 signaling, inflammation, and insulin resistance are associated with affective symptoms and chronic fatigue syndrome due to long COVID.

Al Masoodi, Wasim Talib Mahdi, Radhi, Sami Waheed, Abdalsada, Habiba Khdair et al.·PloS one·2025

This study looked at 90 people, some with Long COVID and some without, to understand why Long COVID patients develop depression, anxiety, and chronic fatigue. Researchers measured several substances in the blood related to inflammation and metabolism. They found that people with Long COVID had higher levels of inflammatory markers and abnormal insulin function, and these changes were linked to their mood and fatigue symptoms.

NeuroinflammationEnergy MetabolismImmune System

E2 ModerateCohortPEM unclearCross-Sectional

Circulating Levels of SMPDL3B Define Metabolic Endophenotypes and Subclinical Kidney Alterations in Myalgic Encephalomyelitis.

Rostami-Afshari, Bita, Elremaly, Wesam, McGregor, Neil R et al.·International journal of molecular sciences·2025

Researchers found that people with ME have lower levels of a kidney protein called SMPDL3B in their blood and urine compared to healthy people. This protein is important for keeping the kidney's filtering system working properly. The study also identified several metabolic imbalances in ME patients' blood that are linked to kidney problems. These findings suggest that kidney function may be affected in ME, and this protein could potentially be used as a simple blood test to help understand the disease.

BiomarkersEnergy Metabolism

E2 ModerateCohortPEM not requiredCase-Control

Alterations in gut microbiota and associated metabolites in patients with chronic fatigue syndrome.

Cheng, Xinxin, Wang, Wenkuan, Xu, Tingting et al.·Scientific reports·2025

This study looked at the bacteria living in the gut of people with ME/CFS compared to healthy people, and found that ME/CFS patients have fewer types of bacteria and lower levels of helpful compounds called short-chain fatty acids (SCFAs) that bacteria produce. The study found that people with ME/CFS who eat more fiber have higher levels of these beneficial compounds, suggesting diet may help restore some of the bacterial imbalances seen in ME/CFS.

Energy Metabolism

E2 ModerateCohortPEM unclearLongitudinal

AI-driven multi-omics modeling of myalgic encephalomyelitis/chronic fatigue syndrome.

Xiong, Ruoyun, Aiken, Elizabeth, Caldwell, Ryan et al.·Nature medicine·2025

Researchers used artificial intelligence to analyze blood, gut bacteria, immune cells, and symptoms from 249 ME/CFS patients tracked over 4 years. The AI model discovered that ME/CFS involves abnormal patterns in gut bacteria products, blood fats, and immune cells that attack infections—particularly special T cells that become overactive. These findings suggest ME/CFS isn't caused by a single problem but by multiple connected systems going wrong together.

BiomarkersGut MicrobiomeEnergy MetabolismImmune System

E2 ModerateCohortPEM unclearCross-Sectional

Leveraging Explainable Automated Machine Learning (AutoML) and Metabolomics for Robust Diagnosis and Pathophysiological Insights in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).

Yagin, Fatma Hilal, Colak, Cemil, Al-Hashem, Fahaid et al.·Diagnostics (Basel, Switzerland)·2025

Researchers used advanced computer learning and blood tests to find chemical markers that could help diagnose ME/CFS. They analyzed 888 different chemicals in blood samples from 106 ME/CFS patients and 91 healthy people, and found a pattern of chemical imbalances that correctly identified ME/CFS patients 87% of the time. The key chemical imbalances involved energy production in cells, inflammation, and gut health—areas that have long been suspected in ME/CFS.

Energy Metabolism

E2 ModerateCohortPEM not requiredCross-Sectional

Functional and Morphological Differences of Muscle Mitochondria in Chronic Fatigue Syndrome and Post-COVID Syndrome.

Bizjak, Daniel Alexander, Ohmayer, Birgit, Buhl, Jasmine Leonike et al.·International journal of molecular sciences·2024

This study examined the energy-producing structures (mitochondria) inside muscle cells of people with ME/CFS and long COVID, comparing them to healthy people. Researchers found that mitochondria in both conditions work less efficiently and have structural damage, but the patterns differ: long COVID shows more damage to a specific energy-producing pathway, while ME/CFS shows more overall structural wear and tear in the mitochondria themselves.

Energy Metabolism

E2 ModerateCohortPEM not requiredObservational

Association between fatigue, peripheral serotonin, and L-carnitine in hypothyroidism and in chronic fatigue syndrome.

Raij, Tommi, Raij, Kari·Frontiers in endocrinology·2024

This study examined whether a supplement called L-carnitine could help reduce fatigue by increasing serotonin levels in the blood. Researchers tracked 12 people with ME/CFS and 40 people with hypothyroidism who were experiencing fatigue, measuring their serotonin and fatigue levels before and after taking L-carnitine for 7 weeks. They found that L-carnitine increased serotonin levels significantly and fatigue decreased by about half in both groups, suggesting a possible connection between low serotonin and fatigue.

BiomarkersEnergy Metabolism

E2 ModerateCohortPEM unclearCase-Control

Case-control study on post-COVID-19 conditions reveals severe acute infection and chronic pulmonary disease as potential risk factors.

Ghosh, Pritha, Niesen, Michiel J M, Pawlowski, Colin et al.·iScience·2024

This study looked at nearly 89,000 COVID-19 patients to understand why some develop long COVID (lasting symptoms months after infection) while others recover quickly. Researchers found that people with a history of lung disease, migraines, or fibromyalgia were more likely to develop long COVID, and those who had severe acute COVID infections were also at higher risk. The findings suggest that reducing the severity of the initial COVID infection, especially in vulnerable patients, might help prevent long COVID from developing.

Energy Metabolism

E2 ModerateCohortPEM unclearLongitudinal

Muscle abnormalities worsen after post-exertional malaise in long COVID.

Appelman, Brent, Charlton, Braeden T, Goulding, Richie P et al.·Nature communications·2024

This study looked at muscle tissue changes in long COVID patients, particularly focusing on post-exertional malaise (PEM)—the worsening of fatigue and pain after activity. Researchers found that muscles in long COVID patients showed structural damage, metabolic problems, and unusual deposits that got worse after activity triggered PEM. These findings help explain why exertion makes symptoms worse in some long COVID patients.

Energy MetabolismPost-Exertional Malaise

E2 ModerateCohortPEM unclearCross-Sectional

Untargeted Metabolomics and Quantitative Analysis of Tryptophan Metabolites in Myalgic Encephalomyelitis Patients and Healthy Volunteers: A Comparative Study Using High-Resolution Mass Spectrometry.

Abujrais, Sandy, Vallianatou, Theodosia, Bergquist, Jonas·ACS chemical neuroscience·2024

Researchers compared blood chemistry between 38 people with ME/CFS and 24 healthy people to understand what might be different in their bodies. They found several chemical imbalances, particularly in how the body processes tryptophan (an amino acid) and in pathways related to energy production and inflammation. These differences suggest that ME/CFS patients may experience unusual immune activity and stress damage to their cells.

Energy MetabolismImmune System

E2 ModerateCohortPEM unclearCross-Sectional

Metabolomic and immune alterations in long COVID patients with chronic fatigue syndrome.

Saito, Suguru, Shahbaz, Shima, Luo, Xian et al.·Frontiers in immunology·2024

This study looked at blood samples from people with long COVID who have ME/CFS-like symptoms and compared them to people who recovered from COVID, people with acute COVID, and people who never had COVID. Researchers found that long COVID patients had unusual chemical patterns in their blood, higher levels of inflammation-promoting substances, and lower energy molecules (ATP). They also discovered that two specific chemicals (sarcosine and serine) were reduced in long COVID patients and connected to depression, anxiety, and brain fog.

Energy MetabolismImmune System

E2 ModerateCohortPEM unclearObservational

Prolonged indoleamine 2,3-dioxygenase-2 activity and associated cellular stress in post-acute sequelae of SARS-CoV-2 infection.

Guo, Lihui, Appelman, Brent, Mooij-Kalverda, Kirsten et al.·EBioMedicine·2023

This study found that people with long-COVID have persistent activity of an enzyme called IDO2 in their blood cells and brain tissue, months or years after initial infection. This enzyme breaks down tryptophan (an amino acid) into other compounds that may trigger cellular stress and energy problems. The researchers also discovered that blocking a specific receptor (called AHR) could stop this process in laboratory tests, suggesting a potential treatment target.

Energy MetabolismImmune SystemPost-Exertional Malaise

E2 ModerateCohortPEM not requiredCross-Sectional

A multi-omics based anti-inflammatory immune signature characterizes long COVID-19 syndrome.

Kovarik, Johannes J, Bileck, Andrea, Hagn, Gerhard et al.·iScience·2023

Researchers compared blood samples from three groups: healthy people, people who recovered from COVID-19 without ongoing symptoms, and people with long COVID who have chronic fatigue and other persistent symptoms. They found that people with long COVID have lower levels of inflammation markers and higher levels of compounds that reduce inflammation, which is unexpected since many assumed long COVID involved high inflammation.

Energy MetabolismImmune System

E2 ModerateCohortPEM not requiredCross-Sectional

Microbiome and metabolome profiles of high screen time in a cohort of healthy college students.

Jasbi, Paniz, Mohr, Alex E, Shi, Xiaojian et al.·Scientific reports·2022

This study looked at gut bacteria and their chemical byproducts in 60 college students who spent either a lot of time on screens (more than 75 minutes daily) or very little time. The researchers found that students with high screen time had different gut bacteria and metabolites than those with low screen time. The findings suggest high screen time might be linked to problems with how cells produce energy and process amino acids, which could connect to conditions like chronic fatigue syndrome and inflammatory bowel disease.

Energy Metabolism

E2 ModerateMechanismPEM requiredObservational

Plasma metabolomics reveals disrupted response and recovery following maximal exercise in myalgic encephalomyelitis/chronic fatigue syndrome.

Germain, Arnaud, Giloteaux, Ludovic, Moore, Geoffrey E et al.·JCI insight·2022

Researchers studied 60 ME/CFS patients and 45 healthy people by measuring thousands of chemical substances in their blood before and after intense exercise tests done 24 hours apart. They found that ME/CFS patients had very different chemical patterns in their blood, especially after exercise and during the 24-hour recovery period, suggesting their bodies struggle to respond to and recover from physical exertion in ways that may explain post-exertional malaise (the worsening of symptoms after activity).

Energy MetabolismPost-Exertional Malaise

E2 ModerateCohortPEM unclearCross-Sectional

A map of metabolic phenotypes in patients with myalgic encephalomyelitis/chronic fatigue syndrome.

Hoel, Fredrik, Hoel, August, Pettersen, Ina Kn et al.·JCI insight·2021

This study examined the chemicals in the blood of 83 ME/CFS patients compared to 35 healthy people to understand how their bodies use energy differently. Researchers found that ME/CFS patients had common metabolic changes suggesting their bodies are working harder to produce energy and are using fats and proteins differently as fuel. Interestingly, patients also fell into different subgroups with distinct metabolic patterns, suggesting ME/CFS may involve different energy problems in different people.

Energy MetabolismPost-Exertional Malaise

← Previous Next 20 studies →

Or browse by topic

PEM Immune Neuro Metabolic Biomarkers Severe ME Long COVID Cognitive

Evidence Atlas

Evidence browser

Does oral coenzyme Q10 plus NADH supplementation improve fatigue and biochemical parameters in chronic fatigue syndrome?

Amantadine and L-carnitine treatment of Chronic Fatigue Syndrome.

Chronic fatigue syndrome and chronic primary magnesium deficiency (CFS and CPMD).

Plasma Extracellular Vesicle Surface Marker Profiling Reveals Immune Cell-Associated Mitochondrial Membrane Potential Alterations in Long COVID and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome.

Increased galanin-galanin receptor 1 signaling, inflammation, and insulin resistance are associated with affective symptoms and chronic fatigue syndrome due to long COVID.

Circulating Levels of SMPDL3B Define Metabolic Endophenotypes and Subclinical Kidney Alterations in Myalgic Encephalomyelitis.

Alterations in gut microbiota and associated metabolites in patients with chronic fatigue syndrome.

AI-driven multi-omics modeling of myalgic encephalomyelitis/chronic fatigue syndrome.

Leveraging Explainable Automated Machine Learning (AutoML) and Metabolomics for Robust Diagnosis and Pathophysiological Insights in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS).

Functional and Morphological Differences of Muscle Mitochondria in Chronic Fatigue Syndrome and Post-COVID Syndrome.

Association between fatigue, peripheral serotonin, and L-carnitine in hypothyroidism and in chronic fatigue syndrome.

Case-control study on post-COVID-19 conditions reveals severe acute infection and chronic pulmonary disease as potential risk factors.

Muscle abnormalities worsen after post-exertional malaise in long COVID.

Untargeted Metabolomics and Quantitative Analysis of Tryptophan Metabolites in Myalgic Encephalomyelitis Patients and Healthy Volunteers: A Comparative Study Using High-Resolution Mass Spectrometry.

Metabolomic and immune alterations in long COVID patients with chronic fatigue syndrome.

Prolonged indoleamine 2,3-dioxygenase-2 activity and associated cellular stress in post-acute sequelae of SARS-CoV-2 infection.

A multi-omics based anti-inflammatory immune signature characterizes long COVID-19 syndrome.

Microbiome and metabolome profiles of high screen time in a cohort of healthy college students.

Plasma metabolomics reveals disrupted response and recovery following maximal exercise in myalgic encephalomyelitis/chronic fatigue syndrome.

A map of metabolic phenotypes in patients with myalgic encephalomyelitis/chronic fatigue syndrome.

Curated Collections

Neuroinflammation Evidence

Metabolism & Mitochondria

Biomarkers

PEM-Specific Research