Long COVID (post-COVID-19 syndrome) affects an estimated 1.9 million people in the UK — 2.9% of the population — with over 500,000 reporting symptoms that significantly limit their daily activities. The UK has emerged as a global leader in long COVID research, with the NIHR and UKRI investing over £100 million in dedicated studies. Here is what is actively recruiting.
The UK was the first country to establish a national network of long COVID specialist clinics (post-COVID assessment services, or PCAS), providing a ready infrastructure for clinical trials. The STIMULATE-ICP and HEAL-COVID trial platforms are some of the largest long COVID studies in the world.
There are currently over 120 actively recruiting long COVID trials in the UK, covering pharmacological, rehabilitative, psychological, and device-based interventions. The National Long COVID Research Consortium coordinates multi-centre trials through the NIHR.
Debilitating fatigue with post-exertional malaise (PEM) is the most common long COVID symptom, affecting over 70% of patients:
Post-exertional pacing strategies — UK trials comparing energy management, heart rate-based pacing, and structured activity modification for PEM reduction
Mitochondrial support — CoQ10, NAD+ precursors, creatine, and carnitine supplementation trials targeting mitochondrial dysfunction in long COVID fatigue
Low-dose naltrexone (LDN) — UK placebo-controlled trials of LDN for long COVID fatigue, following positive ME/CFS data
Graded exercise therapy (GET) and CBT — adapted protocols for long COVID, modified from the PACE trial experience to avoid PEM exacerbation
Transcranial direct current stimulation (tDCS) — targeting prefrontal cortex and motor cortex for fatigue reduction in long COVID
Cognitive Impairment and Brain Fog
"Brain fog" affects 50–60% of long COVID patients and can be as disabling as physical fatigue:
Computerised cognitive training — UK trials of online cognitive rehabilitation platforms targeting attention, working memory, and executive function
Neuromodulation for cognition — transcranial alternating current stimulation (tACS) targeting theta-gamma coupling in prefrontal-parietal networks
Pharmacological cognitive enhancement — trials of modafinil, methylphenidate, and other cognitive enhancers for long COVID brain fog
Occupational and speech therapy — compensatory strategies, metacognitive training, and return-to-work interventions for cognitive symptoms
Biofeedback-based cognitive training — real-time EEG feedback to help patients regulate brain activity patterns associated with cognitive dysfunction
Autonomic Dysfunction
Postural orthostatic tachycardia syndrome (POTS) and other autonomic issues are common in long COVID:
Long COVID POTS trials — UK multi-centre trials comparing beta blockers (propranolol, bisoprolol), ivabradine, fludrocortisone, and midodrine specifically in post-COVID POTS
Non-pharmacological POTS management — trials of high-salt diet, compression garments, counter-manoeuvres, and tilt table desensitisation
Heart rate variability biofeedback — resonance frequency breathing training to improve cardiac autonomic regulation
Post-exertional POTS assessment — using NASA lean test and CPET (cardiopulmonary exercise testing) to quantify autonomic dysfunction and track treatment response
Inflammation and Immune Modulation
Persistent immune dysregulation is hypothesised to drive many long COVID symptoms. UK trials are tackling this directly:
Monoclonal antibodies for novel targets — trials of mAbs targeting immune-inflammatory pathways implicated in long COVID (IL-6, TNF-alpha, complement)
Baricitinib — the JAK inhibitor used in acute COVID, now in long COVID trials for its anti-inflammatory effects at lower doses
Antihistamine combinations — UK trials of H1 and H2 receptor blockers (cetirizine + famotidine, fexofenadine + cimetidine) following positive retrospective data
Metformin — trials testing whether metformin's anti-inflammatory and metabolic effects improve long COVID outcomes
Multidisciplinary Rehabilitation
The NHS post-COVID assessment services provide structured rehabilitation, and ongoing trials are refining these programmes:
Digital rehabilitation programmes — app and web-based long COVID rehab programmes with physiotherapist and occupational therapist supervision
Breathing retraining and respiratory physiotherapy — trials of diaphragmatic breathing, airway clearance, and chest physiotherapy for breathlessness
Return-to-work programmes — structured occupational health interventions to support patients returning to employment after long COVID
Group-based rehabilitation — comparing individual with group rehabilitation delivery for cost-effectiveness and social support benefits
Exercise prescription after CPET — personalised exercise programmes based on cardiopulmonary exercise testing to determine safe exertion thresholds
Who Can Participate?
Long COVID trial eligibility typically requires:
Confirmed prior COVID-19 — documented positive PCR, lateral flow, or antibody test. However, some trials accept symptom-based diagnosis when testing was not available during early pandemic waves
Symptom duration — typically ≥12 weeks after acute infection (NICE definition of post-COVID syndrome), with symptom onset after or persisting beyond the acute phase
Symptom clusters — many trials target specific symptom clusters (fatigue-dominant, respiratory-dominant, cognitive-dominant), so your symptom profile determines suitability
Exclusion of alternative causes — baseline investigations (bloods, ECG, spirometry, chest X-ray) to exclude other explanations for symptoms
Exclusions — active autoimmune disease, significant immunosuppression, pregnancy, and participation in other COVID trials (typically) are common exclusions
💡 Tip: Document Your Symptom Trajectory
Trial teams will want a clear timeline of your COVID infection and subsequent symptom development. Keep a log of your main symptoms (using the Long COVID Symptom Tool or a simple diary), any treatments tried, and how your symptoms have changed over time. Your GP can provide a summary of consultations and investigations. Many trials use the COVID-19 Yorkshire Rehabilitation Scale (C19-YRS) for baseline assessment.
UK Long COVID Trial Locations
Major UK centres running long COVID trials include:
London — UCL, Imperial College, King's College London, Royal Free Hospital (long COVID clinic), St Thomas' Hospital
Birmingham — University Hospitals Birmingham (leading STIMULATE-ICP platform), Birmingham Biomedical Research Centre
Leicester — University Hospitals of Leicester, Leicester Biomedical Research Centre
Manchester — Manchester University NHS Foundation Trust, University of Manchester
Newcastle — Newcastle upon Tyne Hospitals, Newcastle University
Southampton — University Hospital Southampton, NIHR Southampton Clinical Research Facility
Cardiff — Cardiff University, University Hospital of Wales
Edinburgh — University of Edinburgh, NHS Lothian (leading HEAL-COVID platform)
How to Find Your Match
Use our Smart Matcher to find long COVID trials tailored to your dominant symptom cluster (fatigue, brain fog, breathlessness, POTS), symptom duration, and treatment history. Whether you are looking for pharmacological approaches, cognitive rehabilitation, or autonomic management, we can help.
Browse our long COVID condition page for all recruiting studies, or explore related conditions like depression or anxiety if you are managing mental health alongside physical long COVID symptoms.
Find Long COVID Trials For You
Our Smart Matcher uses your symptom profile, duration, and health background to find the most relevant clinical trials.