Choosing a vagus nerve stimulation device
Devices sold under the same name work in quite different ways. Some stimulate the nerve through the ear, some through the neck, and some do not stimulate a nerve at all. This guide sets out what actually differs, so you can choose the one that suits you.
What vagus nerve stimulation is, and what it is not
Implanted VNS is a different thing
Surgically implanted stimulators are approved medical treatments, prescribed for specific conditions. Their evidence does not transfer to devices you buy for home use, which work through the skin and are far gentler.
The ear is the most studied route
Part of the outer ear is supplied by a branch of the vagus nerve, which is why ear stimulation, known as taVNS, can reach it through the skin.¹ Most research on non-invasive stimulation uses this route. Neck devices are studied less.
People respond differently
Responses vary from person to person, and research on taVNS has not found a reliable rise in HRV.² That is why any device promising you a fixed improvement deserves scepticism, including on HRV.
How the main approaches compare
Five well-known devices, grouped by how they work. Details come from each brand's published product information.
| Device | Where it works | What it delivers | How settings are chosen | Typical session | What else it needs |
|---|---|---|---|---|---|
| SONAMindSpire | Ear (taVNS) | Electrical stimulation, combined with a guided breathing pacer and audio soundscapes | Adapts during and between sessions, using its own built-in sensors, including HRV | 5 to 40 minutes | Free app, no subscription. Gel recommended, and a gel pen is included |
| NurosymParasym | Ear, clipped to the tragus | Electrical stimulation | You set the intensity on a handheld controller | 30 to 60 minutes a day recommended | No app or subscription. The ear is moistened before use |
| Pulsetto | Neck, both sides at once | Electrical stimulation | You choose a programme and intensity in the app | Varies by programme | App required. Conductive gel. Optional paid subscription |
| TruvagaelectroCore | Neck, held against one side | Electrical stimulation | You set the intensity | 2 minutes | Conductive gel. App on the Plus model only |
| Apollo Neuro and Sensate | Wrist, ankle or chest | Vibration, and in Sensate's case sound. Not nerve stimulation | You choose a mode or soundscape | Varies | Optional paid app subscriptions |
Competitor details as published by each brand, October 2026. Products and prices change, so check each brand's own site for current information. SONA, and the devices listed, are sold for general wellbeing and are not medical devices.
HRV trackers and SONA do different jobs
Rings, straps and watches such as Oura, WHOOP, Polar and Apple Watch measure HRV well. They report it back to you. SONA measures it too, with its own built-in sensors, but uses it differently.
A tracker measures
It records HRV, usually overnight or across the day, and shows you the trend. It does nothing to your body, which is exactly what you want from a measuring device.
SONA measures, then adapts
SONA reads your HRV during each session as an input, not a target. It uses that signal, together with what it learns between sessions, to adjust the stimulation to you.
In many people HRV dips briefly when stimulation begins. That is a recognised response, which is why we do not promise you a higher number.
Which approach suits you
If you want sessions tailored to you
Choose a device that measures your response and adjusts to it. SONA adapts within each session and from one session to the next.
If you want to wind down in the evening
A short, guided session fits more easily into a bedtime routine than an hour-long one. SONA sessions take 5 to 40 minutes and combine stimulation with a guided breathing pacer and audio soundscapes.
If you would rather not use an app
A device with a simple handheld controller, such as Nurosym, may suit you better. You give up personalisation in exchange for simplicity.
If you are curious but not ready to commit
Start with the free fundamentals: regular sleep, slow breathing and time outdoors. They help whichever device you choose later, and with none at all.
Questions people ask
Do vagus nerve stimulation devices work?
Research on non-invasive vagus nerve stimulation is growing, for both ear and neck devices, and some devices are now approved for specific medical uses. SONA is not yet one of them, and makes no medical claims. Results vary between people, so judge any wellbeing device by how you feel over several weeks of regular use, and be wary of one that promises a fixed result.
Is SONA a medical device?
No. SONA is a wellbeing product. It is not intended to diagnose, treat, cure or prevent any condition, and it is not a substitute for medical care.
What is taVNS?
Transcutaneous auricular vagus nerve stimulation. A gentle electrical signal passes through the skin of the outer ear, where a branch of the vagus nerve, the auricular branch, sits close to the surface. That branch carries signals to the brainstem, mainly to a region called the nucleus of the solitary tract, which relays to areas involved in heart rate, breathing and alertness.¹ There are no implants or needles.
Ear or neck: which is better?
Both routes are used. Ear stimulation has the larger body of data, and the side effects it reports are generally mild and short-lived, such as skin irritation or tingling. That gives the ear route the stronger safety evidence of the two.³ An ear device can also be worn hands-free while you sit or lie down, which makes longer guided sessions easier.
What happens to my HRV during a session?
HRV can move in either direction. In some people it dips when stimulation begins, recovers, and then rises. In others it rises straight away. Both are normal responses, not a sign that something is wrong. SONA uses these changes to tailor the stimulation to you, which is why we treat HRV as an input rather than a score.
Who should not use a vagus nerve stimulation device?
Speak to your doctor first if you have a pacemaker or other implanted electronic device, a heart condition, epilepsy, or are pregnant. Do not use any stimulation device on broken or irritated skin.
Stimulation that adapts to you
SONA measures how you respond and adjusts each session to suit you, in 5 to 40 minutes, combining stimulation with a guided breathing pacer and audio soundscapes.
References
- Butt MF, Albusoda A, Farmer AD, Aziz Q. The anatomical basis for transcutaneous auricular vagus nerve stimulation. J Anat. 2020;236(4):588‑611.
- Wolf V, Kühnel A, Teckentrup V, Koenig J, Kroemer NB. Does transcutaneous auricular vagus nerve stimulation affect vagally mediated heart rate variability? A living and interactive Bayesian meta-analysis. Psychophysiology. 2021;58(11):e13933.
- Kim AY, Marduy A, de Melo PS, et al. Safety of transcutaneous auricular vagus nerve stimulation (taVNS): a systematic review and meta-analysis. Sci Rep. 2022;12(1):22055.