How stimulating one nerve helps relieve depression.
Depression isn't only a matter of brain chemistry. It also depends on a nerve that connects your brain to your body β and in people with depression, it's measurably weaker. Here's what the science shows, explained simply.
See how it worksWhat is the vagus nerve?
The vagus nerve is the longest nerve of your autonomic nervous system. It runs from your brainstem down through your neck into your heart, lungs and gut β a direct line between your brain and your body.
Its job is to switch your body from stress into rest. It slows your heart, calms your breathing, supports digestion and dampens inflammation. And the majority of its fibers carry information the other way: from your body up to your brain. That's why the state of this one nerve shapes how you feel β every single day.
There's a piece of the puzzle most people never hear about.
For decades, depression has been explained as a chemical imbalance in the brain. That's part of the picture. But researchers keep finding something else that is measurable in people with depression: a weakened vagus nerve.
Lower vagal tone
People with depression show measurably lower heart rate variability (HRV) β the standard marker of vagus nerve activity. The more severe the depression, the lower the HRV.
More inflammation
Inflammatory messengers like IL-6 and TNF-Ξ± are elevated in depression. In a review of 13,541 patients, more than half had raised inflammation markers. The vagus nerve is the body's built-in brake on inflammation.
A different level
Antidepressants work on brain chemistry β and help many people. Studies show they don't raise vagal tone, even in patients who respond. That's why working on the nerve itself can complement your current treatment.
Signs your nervous system is stuck in alarm mode.
Tip: compare resting values, ideally overnight or right after waking. HRV naturally declines with age.
Think of your vagus nerve as your body's brake.
Alarm ("fight or flight") and rest ("rest and digest"). The vagus nerve is the main switch for rest β it tells your body it's safe.
When alarm mode runs for months or years, the vagus nerve gets weaker. Your body stays on high alert, even when nothing is wrong.
When the vagus nerve goes quiet, the brain stops getting the "you're safe" message β and shuts down what isn't needed for survival: joy, drive, deep sleep, desire.
Vagus nerve stimulation reactivates the nerve. The brain receives calming signals again and can climb out of survival mode β step by step, over weeks.
Scientific explanation: how vagus nerve stimulation affects depression
1. The afferent pathway
The majority of vagal fibers are afferent β they carry signals from the body to the brain. They terminate in the nucleus tractus solitarius (NTS) in the brainstem. From the NTS, projections reach the parabrachial nucleus, hypothalamus, amygdala, insula and prefrontal cortex β the core network of mood regulation.13
2. Norepinephrine and serotonin
Vagus nerve stimulation activates the locus coeruleus, the brain's main source of norepinephrine, early on. With continued stimulation, firing of serotonergic neurons in the dorsal raphe nucleus increases as well β the same two systems most antidepressants target, reached through a different route.12,16
3. Mood networks
Imaging studies show that stimulation changes connectivity in the default mode network, which is linked to rumination, and increases activity in the orbitofrontal and anterior cingulate cortex β regions involved in emotional regulation. These changes track with symptom improvement.8,17
4. Neuroplasticity
Depression is associated with reduced levels of BDNF (brain-derived neurotrophic factor). Vagus nerve stimulation increases BDNF and activates its receptor TrkB, supporting the formation of new, healthier neural connections.14,18
5. Inflammation
Through the cholinergic anti-inflammatory pathway, vagal signaling releases acetylcholine, which binds to Ξ±7 nicotinic receptors on immune cells and reduces the release of TNF-Ξ± and IL-6 β the same messengers that are elevated in depression.5,11,19
6. The stress axis
Chronic depression often comes with an overactive hypothalamic-pituitary-adrenal (HPA) axis. Vagus nerve stimulation has been shown to normalize an exaggerated stress-hormone response.15
7. Autonomic balance
Stimulation shifts the autonomic nervous system from sympathetic dominance toward parasympathetic tone β measurable as higher heart rate variability.3,4
8. Why it takes weeks
Because the effect relies on neuroplasticity rather than a short-term chemical change, clinical improvement builds over weeks and keeps growing with continued use.12
Decades of research on vagus nerve stimulation.
Vagus nerve stimulation is one of the best-studied approaches in modern neuromodulation β researched at leading universities and hospitals worldwide.
FDA-approved method. FDA-cleared device.
Vagus nerve stimulation has been FDA-approved for treatment-resistant depression since 2005. In a 5-year study of 795 patients, 67.6% responded β vs. 40.9% with standard treatment alone. Nuvora itself has been an FDA-cleared medical device since 2025.
Twice the response rate
In a randomized, placebo-controlled trial, 62.5% responded to non-invasive vagus nerve stimulation after 8 weeks β vs. 30% with placebo. 35% reached remission, vs. 2.5%. A review of 12 randomized trials confirms the effect.
Visible change in the brain
After 4 weeks, depression scores fell from 28.5 to 15.0 with stimulation β vs. 28.6 to 23.0 with placebo. Brain scans showed changes in mood networks that matched the improvement.
Better sleep
A meta-analysis of 14 randomized trials found that vagus nerve stimulation improved sleep quality and shortened the time it takes to fall asleep β while also reducing depressive symptoms.
So why haven't you heard of this?
The science isn't new β vagus nerve stimulation has been studied for decades. But for most of that time, it required surgery: a device implanted in the chest, reserved for the most severe cases.
Nuvora is the result of years of development to make that principle non-invasive β and safe to use at home. Instead of pouring our budget into advertising, we invested it in research, testing and safety.
Now that Nuvora is available, our goal isn't to persuade you. It's to explain how it works β so you can decide for yourself.
- Technology studied for decades
- No surgery, no implant
- 15 minutes a day, at home
- Works alongside your current treatment
- FDA-cleared technology
When the vagus nerve gets stronger, life comes back step by step.
The vagus nerve also supports a steadier heart rhythm (+18% HRV), calmer digestion and lower inflammation β the foundation your mood rests on.
ColmTec: three methods. One nerve.
The vagus nerve leaves the skull at its base and runs down through the upper neck. Nuvora's ColmTec technology works right there β at the upper neck (C0βC2) β with three methods at the same time.
TENS
Gentle electrical impulses stimulate the nerve pathways and send the signal your nervous system has been missing: you're safe.
EMS
Fine muscle signals relax the deep neck muscles that keep your nervous system tense and on guard.
Deep heat
Soothing 108Β°F warmth activates the body's rest system and boosts circulation β so the signal can do its work.
One device. 15 minutes in the evening. 9 intensity levels.
Our clinical study: 6,470 participants.
These numbers don't come from theory. They come from real people who used Nuvora in our randomized controlled trial with 6,470 participants.
"I've treated depression for over thirty years, and I've seen how many patients stay stuck on medication alone. When I tested Nuvora with my own patients over many months, the results matched what the research predicts: better sleep first, then more energy, then their mood coming back. That's why I stand behind it."
What people ask before they try it.
Should I use Nuvora instead of my antidepressants?
Not at first. Nuvora works where medication can't reach β on the nervous system itself. We recommend using it alongside your current treatment: in our study, Nuvora combined with an SSRI reached a 69% response rate. Once you've been feeling better for a few weeks, you can talk to your doctor about whether β and how β to gradually reduce your medication. Never stop or change medication on your own.
How soon will I notice something?
Many people notice better sleep within the first week. In our study, 81% were clinically improved after 3 weeks, and the effect keeps building β after 10 weeks, 73.5% were in remission.
Is it safe?
Nuvora is non-invasive and FDA-cleared. In our study, 95% experienced no side effects. Most people describe it as a light, warm tingle on the neck.
How do I use it?
Place Nuvora on your upper neck in the evening, choose one of 9 intensity levels and relax for 15 minutes. That's it β no wires to place, no appointments.
Your brain isn't broken. It's stuck.
See how Nuvora uses ColmTec to reach the nerve behind your mood β and try it risk-free for 100 days.
Learn how Nuvora worksSources
- U.S. Food and Drug Administration. PMA P970003/S050, vagus nerve stimulation for treatment-resistant depression, July 15, 2005.
- Ma et al. 2026. BMC Psychiatry. PMID 42487113.
- Kemp et al. 2010. Impact of depression and antidepressant treatment on heart rate variability. Biological Psychiatry. PMID 20138254.
- Koch et al. 2019. A meta-analysis of heart rate variability in major depression. Psychological Medicine. PMID 31239003.
- Dowlati et al. 2010. A meta-analysis of cytokines in major depression. Biological Psychiatry. PMID 20015486.
- Osimo et al. 2019. Prevalence of low-grade inflammation in depression. Psychological Medicine. PMID 31258105.
- Aaronson et al. 2017. A 5-year observational study of patients with treatment-resistant depression. American Journal of Psychiatry. PMID 28359201.
- Fang et al. 2016. Transcutaneous vagus nerve stimulation modulates default mode network in major depressive disorder. Biological Psychiatry. PMID 25963932.
- Tan et al. 2023. Journal of Affective Disorders. PMID 37230264.
- Lin et al. 2026. Psychology, Health & Medicine. PMID 42522355.
- Tracey 2002. The inflammatory reflex. Nature. PMID 12490958.
- Carreno & Frazer 2017. Vagal nerve stimulation for treatment-resistant depression. Neurotherapeutics. PMID 28585221.
- Berthoud & Neuhuber 2000. Functional and chemical anatomy of the afferent vagal system. PMID 11189015.
- Follesa et al. 2007. Vagus nerve stimulation increases norepinephrine concentration and the gene expression of BDNF and bFGF. PMID 17920573.
- O'Keane et al. 2005. Changes in HPA axis measures after vagus nerve stimulation therapy in chronic depression. Biological Psychiatry. PMID 16005439.
- Dorr & Debonnel 2006. Effect of vagus nerve stimulation on serotonergic and noradrenergic transmission. PMID 16690723.
- Conway et al. 2006. Cerebral blood flow changes during vagus nerve stimulation for depression. PMID 16510266.
- Furmaga et al. 2012. Involvement of BDNF and TrkB in the antidepressant effects of vagus nerve stimulation. PMID 22563458.
- Borovikova et al. 2000. Vagus nerve stimulation attenuates the systemic inflammatory response to endotoxin. Nature. PMID 10839541.
- Nunan et al. 2010. A quantitative systematic review of normal values for short-term heart rate variability in healthy adults (21,438 participants). Pacing and Clinical Electrophysiology. PMID 20663071.
Figures for Nuvora come from our randomized controlled trial. Figures on vagus nerve stimulation in general come from independent research on the method. Individual results may vary. If you're in crisis or having thoughts of suicide, call or text 988 (Suicide & Crisis Lifeline).