This article explores the emerging role of vagus nerve stimulation (VNS) as a supportive therapy for ME/CFS, fibromyalgia (FM), and long COVID. The vagus nerve plays a major role in regulating inflammation, heart rate, digestion, stress responses, and communication between the body and brain. Because these systems are often disrupted in energy-limiting illnesses, stimulating the vagus nerve has become a promising area of research.
Study Background and Intervention
Non-invasive VNS devices work by delivering gentle electrical pulses to the ear, where parts of the vagus nerve are accessible. These pulses activate the parasympathetic (“rest and digest”) system and may help calm the sympathetic dominance commonly seen in ME/CFS, FM, and long COVID. Dr. Ben Natelson’s team at Mount Sinai is currently running a long COVID VNS study using the Parasym™ device. Participation is simple: eligible people complete a phone/Zoom screening and then use the device at home for 35 minutes each morning over 12 weeks. Early pilot work showed improvements for a subset of patients, especially those who were not severely ill.
Key Findings
Low heart rate variability (HRV)—a sign of reduced parasympathetic activity—is common across ME/CFS, fibromyalgia, long COVID, and related conditions. Because VNS directly targets this system, it may help restore balance. Although research is still in its early stages, studies have reported reduced pain and autonomic symptoms in fibromyalgia, improvements in anxiety, cognition, sleep, and eventually fatigue in long COVID, increases in HRV and reductions in inflammatory markers in POTS, and decreased inflammation in autoimmune conditions such as rheumatoid arthritis. While results differ from person to person, many investigations have shown meaningful improvements with minimal side effects, suggesting that VNS may offer a helpful supportive therapy for a subset of individuals.
Broader Evidence and Theoretical Benefits
VNS signals the brainstem and links to regions involved in pain, fatigue, autonomic control, mood, and stress regulation—areas often affected in ME/CFS and FM. By activating the body’s anti-inflammatory reflex, VNS may reduce chronic inflammation and help stabilise autonomic nervous system function. Breathing is also important. Studies show that around 25% of people with ME/CFS hyperventilate during activity, while another 25% use breathing patterns that increase fatigue. Slow, diaphragmatic breathing can activate the vagus nerve naturally and may enhance the effects of VNS.
Practical Considerations
Non-invasive VNS devices offer a low-risk option. Sessions typically last about 30 minutes and can be done at home. Benefits tend to build gradually over several weeks. Although VNS is not a cure, it may improve sleep, stress tolerance, energy, autonomic function, and overall quality of life for some people. Large research initiatives, including major NIH projects, are working to refine stimulation settings and develop more precise, disease-specific devices. As understanding grows, the effectiveness of VNS is expected to improve.
Conclusion
Vagus nerve stimulation is an emerging tool with real potential to support symptom management in ME/CFS, fibromyalgia, and long COVID. While more large, controlled studies are needed, early research is encouraging. For now, VNS offers a safe, accessible option that may help ease autonomic dysfunction, improve sleep and mood, and support daily functioning.
Reference
Johnson, C. (2025, September 16). The Promise of Vagus Nerve Stimulation – and the No Brainer Long COVID Trial Underway. Health Rising. https://www.healthrising.org/blog/2025/09/16/vagus-nerve-stimulation-long-covid-me-cfs-fibromyalgia/