BY Samuel Mathis MD
Recently, my social media feed has been filled with advertisements for a new vagus nerve stimulator that works by using a device around the neck. These devices promise everything from improved heart rate, better sleep, lower cortisol levels, improved gut health, and improved mood and anxiety levels. As with any integrative therapy, I am skeptical of anything that sounds too good to be true. This led me to research external vagus nerve stimulators and the science behind them.
The vagus nerve has multiple functions, primarily related to its role in activating the parasympathetic nervous system, or the “rest and digest” function, as I was taught in medical school. This role is incredibly important as high vagal tone lowers stress levels, improves blood pressure, and helps the body reduce inflammation. It functions as a natural cardiac regulator to maintain an appropriate cardiac rhythm and stimulates the GI tract to digest our food. New studies in psychology are linking the vagus nerve to mental health and sports performance. Vagus nerve stimulators work by delivering a gentle electrical impulse to the vagus nerve along its course, either in the neck or in the ear. The thought process is that these impulses act as a semi-stimulator of the vagus nerve, causing increased vagal tone, the release of serotonin and norepinephrine in the brain, and signaling the body to reduce production of inflammatory cytokines. We know that deep vagus nerve stimulators do work to help with certain neurological conditions, but how effective are the transcutaneous stimulators?
Interestingly, there is evidence that supports these claims. A review of 109 studies found that transcutaneous auricular vagus nerve stimulation improved symptoms of depression and anxiety, reduced seizure frequency in epileptic patients, and even improved cardiac parameters in patients with paroxysmal afib, heart failure, post-MI patients, and those with postural tachycardia syndrome (1). The study also found some improvement in stroke patients, migraines, pain conditions, and patients with insomnia (1). Other conditions where transcutaneous auricular stimulation is being used include autoimmune conditions, dyspepsia, irritable bowel syndrome, traumatic brain injury, restless leg syndrome, Parkinson’s, and even opioid withdrawal syndrome, though there are only a few small studies for each of these conditions (1).
The other form of vagus nerve stimulation is a cervical device that sits around the neck instead of the ear. The evidence for this form of vagal stimulation is not as strong as auricular therapies. One study recently found that transcutaneous cervical nerve stimulation was not effective at creating deep cervical vagus nerve activation compared to auricular stimulation. This study used a triple-arm grouping of auricular, cervical, and sham vagus nerve stimulation. While the auricular therapy was successful in stimulating the deep cervical nerve activation threshold, they found the cervical and sham did not stimulate the nerve (2). This raises concerns about the veracity of claims surrounding cervical vagus nerve stimulation therapies. This may be overcome by use of stronger stimulation, but more research is needed to verify its effectiveness.
How then do we recommend transcutaneous vagus nerve stimulators for our patients? For patients who desire to explore this therapy option, I recommend auricular stimulators over cervical neck stimulators. The stimulator should be used a few times a week to once or twice per day, depending on the underlying condition working to be treated. I often recommend patients increase the stimulation to where they feel slightly uncomfortable with the strength of the stimulus. Treatments typically range from 15-60 minutes, and results may not be seen for up to 2-4 weeks. Some common side effects include irritation at the site, and sore ears following a treatment are also normal. If a rash or severe pain develops, patients should discontinue use of the device immediately. Transcutaneous vagus nerve stimulators are an interesting new option for patients seeking integrative therapies. I am excited to see the continuing research on these therapies and other conditions they may impact in the future.
Citations:
- Gerges ANH, Williams EER, Hillier S, Uy J, Hamilton T, Chamberlain S, Hordacre B. Clinical application of transcutaneous auricular vagus nerve stimulation: a scoping review. Disabil Rehabil. 2024 Dec;46(24):5730-5760. doi: 10.1080/09638288.2024.2313123. Epub 2024 Feb 16. PMID: 38362860.
- Yang X, Wei M, Jiao Y, Xue X, Liu Y, Li R, Zeng X, Sun J, Qin W. Site-specific stimulation imperative: Lessons from a failed auricular-cervical transcutaneous vagus nerve stimulation comparison using closely matched parameters. Brain Stimul. 2026 Mar-Apr;19(2):103022. doi: 10.1016/j.brs.2025.103022. Epub 2025 Dec 31. PMID: 41482152.