Working document · updated as we go

Our ME/CFS Research Log

A running, evidence-graded review of what's actually been studied on ME/CFS causes and treatments — built because "have you tried googling it" is not a referral pathway. Every entry below is graded by source quality, not vibes.

16 of 24 categories reviewed 155 sources logged 3 promising leads, 2 ruled out Last updated 30 Jul 2026

What we know so far

The clearest verdicts — good or bad

Three things have cleared the bar for genuinely decent evidence, and two have been ruled out clearly enough that they're worth knowing even if you never look at the rest. Everything else reviewed so far is real but inconclusive — see the full board below.

Infection can genuinely trigger this

Promising

A large NIH-funded study (RECOVER-Adult, 2025) tracked 11,785 people infected with SARS-CoV-2 against 1,439 uninfected people. The infected group was roughly five times more likely to go on to develop ME/CFS. Earlier studies going back to 2006 show the same pattern with other infections (glandular fever, Ross River virus) — the people who got sickest during the initial infection were the ones most likely to develop lasting illness afterward.

This doesn't explain every case — plenty of people develop ME/CFS with no clear preceding infection — but it's the single best-evidenced trigger found in this research so far.

Why it matters: this is a measurable, replicated, physiological response to infection, tracked in large controlled studies. Not a mystery, not "in your head."

12 sources reviewed · see sources.csv, category "Post-viral/post-infectious onset"

Pacing is the one thing every guideline agrees on

Promising

NICE (UK) and the CDC (US) both recommend staying inside a personal "energy envelope" — tracking what you can actually do without triggering a crash, and not exceeding it — over any fixed, incrementally-increasing exercise program. In 2021, NICE formally reversed its older guidance and now explicitly warns against Graded Exercise Therapy (GET), the "push through it, build up slowly" approach.

A 2019 patient survey of 2,310 people found roughly 45% reported improvement from pacing, versus roughly 10% from GET or CBT-based approaches — that survey was part of the evidence that led to NICE's reversal.

Why it matters: if a GP, an old leaflet, or a well-meaning relative suggests "just build up your exercise," that guidance has been formally withdrawn by NICE. It's not a lack of willpower — pushing through can make things worse.

12 sources reviewed · see sources.csv, category "Pacing / energy envelope management"

Structured exercise programs (GET) have been withdrawn as advice

Ruled out

Graded Exercise Therapy — fixed, incrementally-increasing exercise — used to be standard advice, built on a 2011 trial (PACE) that claimed strong recovery rates. An independent 2018 reanalysis of that trial's own data, using its original pre-registered scoring rules instead of the loosened ones actually published, found "recovery" rates fell from a claimed 60% to just 20%, and the difference from doing nothing stopped being statistically real.

Both NICE and the CDC have formally withdrawn GET as a recommendation. A large UK patient survey found 74% of people who tried it said it made them worse.

Why it matters: this is the single most actionable finding in this research so far. If anyone suggests a fixed, build-up exercise program as a treatment, the evidence it was based on didn't hold up, and the guidance has been officially reversed since 2021.

10 sources reviewed · see sources.csv, category "Graded Exercise Therapy (GET)"

Mast cell issues show up often enough to be worth checking

Promising

Mast Cell Activation Syndrome (MCAS) — where immune cells release excess histamine and other mediators — turned up in roughly 17–25% of ME/CFS patients across the largest study found (over 1,000 people combined). People with both conditions had noticeably more orthostatic intolerance (standing-up problems), and responded significantly better to mast-cell-targeted treatment than those without it.

This is genuinely early-stage: no randomized trials exist yet, and even a leading ME/CFS clinic (Bateman Horne Center) says plainly there's "no robust research to confirm a link" despite seeing it constantly in practice.

Why it matters: if certain symptoms (flushing, hives, reactions to heat/food/fragrance) are part of the picture, it may be worth asking a GP about MCAS specifically — not as a proven fix, but as a genuinely plausible, testable comorbidity.

9 sources reviewed · see sources.csv, category "Mast cell activation syndrome (comorbid)"

"It's not in your head" isn't just reassurance — it's the evidence

Ruled out

For decades, some UK psychiatric medicine framed ME/CFS as perpetuated by "false illness beliefs" — the theory that justified CBT/GET as a cure. Both NICE and the 2015 Institute of Medicine report formally rejected this after reviewing the evidence. The most direct test came from a huge Dutch population study (Lifelines, ~136,000 people): among people with no prior fatigue, having a pre-existing psychiatric diagnosis did not predict who went on to develop ME/CFS.

This doesn't mean mental health is irrelevant — living with any severe chronic illness genuinely causes real rates of depression and anxiety, and that's worth taking seriously and treating. But that's a consequence of being sick, not the cause of it, and conflating the two is exactly the mistake this field made for years.

Why it matters: around 90% of ME/CFS patients report being told at some point their symptoms were psychosomatic before diagnosis. That framing has been formally withdrawn by the bodies that once endorsed it.

9 sources reviewed · see sources.csv, category "Psychological/psychiatric factors"

Full status board

Every category we're tracking

Click a row to expand our working notes. Source counts and confidence grow as we work through the list — nothing here is final.

Possible Causes

Post-viral / post-infectious onset 12 sources Promising ▸
Best-evidenced trigger found so far — large matched-control studies (COVID and earlier viruses) consistently show a dose-related minority developing ME/CFS after infection, tied to how severe the initial illness was. Explains a subset of cases, not all of them; what happens biologically after the trigger is still unclear (immune dysregulation is the leading candidate).
Immune dysregulation / chronic immune activation 14 sources Inconclusive ▸
Reduced natural killer (NK) cell activity is well-replicated across multiple independent reviews — one of the more solid objective findings in the field. But general inflammation markers (cytokines) are inconsistent study to study, and the largest single study found cytokines track with how severe someone's illness is, not whether they have it at all. Autoimmune-antibody findings are real but only show up in a subset (roughly a quarter) of patients.
Autonomic nervous system dysfunction (POTS, orthostatic intolerance) 10 sources Inconclusive ▸
Genuinely common and clinically significant — heart rate, blood pressure, and even blood flow to the brain on standing are frequently abnormal. But the best-powered study comparing ME/CFS patients to other fatigued patients found no meaningful difference in how common POTS was between the two groups — suggesting this may be a common companion condition rather than a distinguishing cause. Testing methods also vary a lot between studies.
Mitochondrial / metabolic dysfunction 12 sources Inconclusive ▸
The body's response to exertion is measurably and reproducibly abnormal — this is essentially the physical signature of post-exertional malaise. But whether that's caused by broken mitochondria specifically, or something further upstream (like oxygen delivery), is unresolved. One well-designed study found normal mitochondrial function in cells despite clearly abnormal real-world exercise performance in the same patients.
Neuroinflammation / CNS sensitization Not started
HPA axis dysfunction (cortisol/stress response) 10 sources Inconclusive ▸
The signal itself is real and well-replicated — mild low cortisol, blunted daily cortisol rhythm, and an exaggerated shutdown response, going back to a 1991 foundational study through a 2026 meta-analysis. It's biologically distinct from the high cortisol seen in classic depression. But the causal test undercuts it: replacing the missing cortisol with hydrocortisone only produced modest, short-term improvement in one trial, and in another, a higher dose caused clinically significant adrenal suppression severe enough the authors ruled out practical use. Most likely a downstream marker, not a fixable root cause.
Gut microbiome / gastrointestinal dysfunction Not started
Genetic / epigenetic predisposition Not started
Small fiber neuropathy Not started
Mast cell activation syndrome (comorbid) 9 sources Promising ▸
Early-stage but a genuine signal: the largest dataset found (n=687 + n=383) shows 17–25% comorbid prevalence, strongly linked to orthostatic intolerance, with a highly significant treatment-response difference favoring mast-cell-targeted therapy. Tempered by: no randomized trials exist yet, neither NICE nor the 2015 IOM report engages with MCAS at all, and the field's own diagnostic gold standard (a blood test called tryptase) is stricter than what most of these studies actually used. Plausible and patient-embraced, not yet formally proven.
Sleep architecture abnormalities 9 sources Inconclusive ▸
Objective sleep-study differences do exist on average (less efficient sleep, longer time to fall asleep, more awakenings) but are inconsistent study to study and, tellingly, don't track with how bad someone's "unrefreshing sleep" complaint actually is — an odd disconnect. The 2015 IOM report was explicit that standard sleep studies usually look basically normal despite the complaint being near-universal. One practical note: a study of patients referred for suspected ME/CFS found about 40% actually had obstructive sleep apnea on testing — worth ruling out a separate, treatable sleep disorder before assuming it's just "part of the illness."
Psychological / psychiatric factors 9 sources Ruled out ▸
See the featured write-up above — ruled out specifically as a primary cause of the illness, not as a claim that mental health doesn't matter once you're sick. NICE and the IOM both formally rejected the older "false illness belief" model; the strongest direct test (a ~136,000-person Dutch cohort) found pre-existing psychiatric diagnosis didn't predict who went on to develop ME/CFS. Secondary depression/anxiety from living with a severe chronic illness is real and well-documented — that's a consequence, kept clearly separate here from cause.

Possible Treatments

Pacing / energy envelope management 12 sources Promising ▸
Unanimously endorsed by NICE, the CDC, and the 2015 IOM report as safer and more appropriate than structured exercise. Meta-analyses show a moderate, consistent reduction in fatigue, and one 2025 review found pacing's benefits held up at 2.5-year follow-up where GET's did not. Caveat: no large multi-site trial exists yet, and in one survey around 14% of patients said pacing made things worse for them — individual variation matters.
Graded Exercise Therapy (GET) 10 sources Ruled out ▸
Ruled out as a recommended standard treatment — not a flat "never helps under any protocol." Both NICE (2021) and the CDC (2017) now advise against fixed-incremental exercise programs. The flagship 2011 trial that justified GET (PACE) was substantially undermined by an independent 2018 reanalysis using its own pre-registered scoring: claimed 60% recovery fell to 20% and lost statistical significance. A large patient survey found 74% who tried GET said it made them worse. A Cochrane review still says exercise therapy probably helps, but that review is itself under open dispute within Cochrane for being outdated.
CBT 10 sources Inconclusive ▸
Splits by framing. As coping support for living with a chronic illness: plausible and low-controversy, recent large meta-analyses show real, modest benefit. As treatment for the underlying disease (the historically contested claim, built on the same PACE trial as GET, above): doesn't hold up — the same independent reanalysis found CBT's claimed recovery rates collapsed under the original scoring rules. NICE and the CDC have both formally withdrawn CBT's status as a cure. Nearly every study on both sides relies on self-reported outcomes rather than objective measures.
Low-dose naltrexone (LDN) 8 sources Inconclusive ▸
Evidence doesn't yet back the patient-community buzz. NICE explicitly declined to recommend it in 2021 for lack of placebo-controlled trials — and that gap still hasn't been filled: only a small uncontrolled retrospective study (n=218, no placebo arm, ~74% reported a positive response) exists for ME/CFS specifically. Stronger results exist for related conditions (fibromyalgia, Long COVID) but aren't ME/CFS-specific. A large patient survey rated LDN the single most effective treatment tried — worth discussing with a doctor given its low cost and risk, but not yet clinically proven. Two real trials are underway.
Antiviral therapy 9 sources Inconclusive ▸
A consistent split: general ME/CFS populations show no benefit from antivirals (a 1988 placebo-controlled trial found nothing). But patients specifically selected for elevated EBV/HHV-6 antibody levels showed a possible, unconfirmed benefit in a small trial (30 people) — never independently replicated since, despite the same researchers calling for exactly that follow-up. NICE reviewed this in 2021, rated it very low quality, and doesn't recommend it. Bottom line: any positive signal applies to an antibody-tested minority, not everyone.
Supplements (CoQ10, D-ribose, carnitine, B vitamins, magnesium) 11 sources Inconclusive ▸
Not all supplements are equally evidenced. CoQ10 (especially paired with NADH or selenium) has the strongest case: the largest trial here (207 people) and the most recent systematic review both found real, statistically significant fatigue reduction. Magnesium, D-ribose, carnitine, and B12 each rest on only one or two small, old, or uncontrolled studies — meaningfully weaker evidence. Neither NICE nor two independent reviews recommend any supplement outright given the small sample sizes involved, but CoQ10 is the one worth an actual conversation with a doctor about.
POTS-directed treatment 9 sources Inconclusive ▸
Splits cleanly by type. Non-drug measures (salt/fluid loading, compression garments, careful posture changes) have the most consistent support and the lowest risk — one ME/CFS-specific trial found compression stockings measurably improved blood flow to the brain during standing tests. Medication is a mixed bag: beta-blockers and pyridostigmine both showed some benefit, but fludrocortisone — a mainstay for POTS generally — was tested head-to-head against placebo in ME/CFS patients specifically and failed outright. No guideline body recommends a specific drug order; both defer to specialist judgment.
Sleep management Not started
Antihistamines / mast cell stabilizers 0 dedicated sources In progress ▸
Not yet independently reviewed — surfaced as a side note from the MCAS comorbidity research above. One finding worth flagging early: a small case series (5 patients) found high-dose oral cromolyn sodium improved symptoms in ME/CFS patients with confirmed MCAS who hadn't responded to standard dosing. Too small and uncontrolled to call promising on its own — needs its own proper pass.
Immunomodulatory therapy (rituximab, IVIG) Not started
Dietary interventions Not started
Emerging / repurposed drug trials Not started

What's next

8 categories still untouched

Causes

  • Neuroinflammation / CNS sensitization
  • Gut microbiome / GI dysfunction
  • Genetic / epigenetic predisposition
  • Small fiber neuropathy

Treatments

  • Sleep management
  • Antihistamines / mast cell stabilizers (finish proper review)
  • Immunomodulatory therapy
  • Dietary interventions
  • Emerging / repurposed drug trials