In 1994 the neuroscientist Stephen Porges proposed polyvagal theory: that the vagus nerve has two distinct branches which evolved in sequence, and that human beings move between three autonomic states — social engagement, fight-or-flight, and shutdown — according to unconscious threat detection he named neuroception. It was a theory about physiology. It became something much larger.

The route out of the laboratory ran through trauma therapy. Clinicians found the model intuitive and humane: it reframed freezing, dissociation and collapse as automatic protective states rather than personal failures. Deb Dana turned it into teachable practice, and through her work the vocabulary — ventral, dorsal, regulation, co-regulation — reached hundreds of thousands of therapists. Alongside it, and often blended with it, ran Peter Levine's Somatic Experiencing, a separate tradition with its own lineage that the popular literature rarely distinguishes.

From there it reached everyone. The language escaped clinical practice into Instagram, then into products. If the nervous system is the thing to fix, something can be sold to fix it — and because the vagus nerve is reachable from the skin of the neck and ear, a device category followed. By 2026 the Global Wellness Summit was naming neurowellness one of its ten trends of the year, splitting it into lo-fi somatic practice on one side and consumer neurotech on the other.

Then, in September 2026, thirty-nine autonomic researchers led by Paul Grossman published a comprehensive challenge. Their objections were specific: there is no evidence for the role polyvagal theory assigns the dorsal vagus; respiratory heart-rate variability is an approximate proxy for vagal activity, not the direct measure the theory treats it as; and the evolutionary claim fails, because complex social behaviour exists in vertebrates that lack the branch said to make it possible. The Polyvagal Institute maintains a standing critical-discussion page, and a formal scholarly rebuttal has been published. This is a live scientific dispute, not a closed one.

The part that gets lost in the headlines is the part that matters most. Grossman does not say somatic practice is worthless. He says the opposite: meditation, yoga and relaxation predate polyvagal theory by centuries and may well remain beneficial without it, and practitioners should reach for other established psychophysiological explanations rather than this one. The claim under challenge is the explanation, not the experience.

This category is unusually easy to check, because the gap between what is claimed and what is shown tends to sit in plain sight. These are the questions we apply to every listing in it.

Fourteen listings sit under Nervous System & Neurowellness, deliberately spanning the full evidence range rather than only the credible end. At the regulated end: Flow Neuroscience, electroCore (gammaCore), Nurosym and Alpha-Stim. In the consumer-wellness middle: Apollo Neuro, Sensate and Elemind. At the weak end, and listed for prominence rather than substantiation: Pulsetto.

The people who built the vocabulary are listed too — Stephen Porges, Deb Dana and Peter Levine — along with Somatic Experiencing International in Boulder, Colorado, which issues the SEP credential and is one of the few verification anchors the practitioner side of this field has. Two events are listed: PESI's clinician summit, and one of the free online summits that now saturate the space, included with a note on how that format actually works.

Apollo Neuro deserves a specific mention for something it does rather than sells: it states plainly that it is a consumer wellness device, does not require FDA approval, and is not intended to treat or cure anything. That disclosure is unusual enough in this category to be worth naming.