The vagus nerve has FDA-approved treatments, while the viral hacks are untested

Key takeaways

• In a 2015 trial in 10 English emergency departments, a modified Valsalva maneuver restored normal rhythm within a minute in 43% of people with a racing heart, compared with 17% who got the standard version¹.
• Implanted vagus nerve stimulators have been used for epilepsy since 1997 and were approved for hard-to-treat depression in 2005, though a trial against a sham device found no clear benefit at three months⁵⁷.
• In February 2026, a group of 39 scientists called polyvagal theory “untenable,” and its creator, Stephen Porges, replied that they had tested a distorted version of it¹⁰¹¹.
• We found no good trials showing that humming, gargling or “vagus nerve exercises” improve health, and a review of ear-stimulation trials rated most of them at risk of bias¹².
• Feeling faint when you stand, or new changes in bowel, bladder or sexual function, can signal a real autonomic problem worth a medical visit³.

In 2015, doctors at 10 emergency departments in England tested a simple fix for a racing heart, in a trial called REVERT¹. Their patients had supraventricular tachycardia, a fast rhythm that starts above the heart’s main pumping chambers.

Each patient strained by blowing hard against resistance for about 15 seconds, a move called the Valsalva maneuver¹. Half of them then lay flat right away with their legs raised¹.

Among 428 adults, 43% of the leg-raise group were back in normal rhythm a minute later, compared with 17% of the standard group¹.

That is a vagal maneuver. It uses the body’s own wiring to brake the heart, and American heart guidelines recommend such maneuvers as a first step². Most viral “vagus nerve hacks” have nothing like that behind them.

Your body’s autopilot has an accelerator and a brake

The autonomic nervous system is the part of your nervous system that works without your say-so. It sets your blood pressure and heart rate, controls sweating, and moves food and waste through your gut and bladder³.

It has two main branches, the sympathetic and the parasympathetic⁴. The sympathetic side acts like an accelerator. When it runs too hot, blood pressure and pulse can climb, according to the National Institute of Neurological Disorders and Stroke (NINDS)⁴.

The parasympathetic side acts more like a brake. It helps you rest, digest and recover. Many scientists also count a third branch, the enteric nervous system, a web of nerves in the gut wall. Our gut-brain article covers that one.

The vagus nerve is the parasympathetic system’s star player. It passes through the neck, where surgeons can reach it⁵⁶. Its right branch supplies the heart, which is why implanted stimulators go on the left side instead⁵.

Implanted stimulators seem to work mainly by sending messages up the nerve to a brainstem relay station that connects to brain areas involved in mood⁷.

Polyvagal theory is popular with therapists and disputed by physiologists

In a 1995 paper in Psychophysiology, Stephen Porges, now a scientist at Indiana University’s Kinsey Institute, laid out what he called the polyvagal theory⁸. It proposes that the vagus works through two circuits with different jobs and different evolutionary histories⁸.

In this model, a newer “ventral” circuit, based in a brainstem area called the nucleus ambiguus, runs what Porges calls the social engagement system. An older “dorsal” circuit is tied to going still, or immobilizing, under threat⁸. Porges also coined the word “neuroception” for the brain’s below-awareness scan for safety or threat⁸.

Many therapists who treat trauma have embraced this map. A 2023 commentary in the Journal of Psychiatry Reform granted that critics raise valid points about the biology. Its authors still called the framework useful for trauma recovery and mind-body healing⁹.

In 2023, researcher Paul Grossman challenged five core premises⁹. He argued that the nucleus ambiguus, not the dorsal circuit, drives the vagus nerve’s slowing of the mammalian heart. He added that the supposedly mammal-only social circuitry has counterparts in other animals⁹.

Grossman also took on a favorite measure. Your heart rate rises a little as you breathe in and falls as you breathe out, and he argued that this rhythm shows how breathing shapes the vagus nerve’s grip on the heart, not your overall “vagal tone”⁹.

In February 2026, Grossman and 38 co-authors, experts in vagus physiology, evolution and animal behavior, went further¹⁰. They concluded that the theory’s main tenets lack support and in places conflict with the evidence. They called it “untenable”¹⁰.

Porges replied in the same issue of Clinical Neuropsychiatry. He argued that the critics had tested a stand-in of their own making rather than the theory as he wrote it. In his view, their objections come down to choices about measurement and framing¹¹.

What does that mean for you? The critics argue that the theory’s psychological ideas came mostly from earlier psychology¹⁰. If so, the parts many therapists value, such as feeling safe, connecting with others and noticing your body, don’t hinge on this wiring diagram. The specific claims about vagal branches are in serious dispute, so be wary of any product or program that promises to “reset” one.

A vagal maneuver that works, with a doctor’s guidance

In REVERT, patients strained while half-reclining, the usual position, by blowing into a pressure gauge or a syringe¹.

Why would posture help? Lying flat with the legs up may send more blood back to the heart, which in turn stirs the vagus nerve to slow it, according to a summary from the UK’s National Institute for Health and Care Research (NIHR)¹.

NIHR, a public research funder, paid for the trial¹. An independent expert checked each heart tracing, and no one had a serious side effect¹. People with very low blood pressure were excluded¹.

There were limits. Success was measured only one minute after the maneuver, and most people in the modified group did not convert from the maneuver alone¹.

The 2015 U.S. guideline from the American College of Cardiology, American Heart Association and Heart Rhythm Society gives vagal maneuvers its strongest recommendation as a first treatment for this kind of regular fast rhythm, and says patients should be taught how to do them².

This is a treatment for a diagnosed rhythm problem, not a relaxation exercise. If you have one, ask your cardiologist whether a maneuver like this suits you.

Four vagus nerve treatments have FDA approval or clearance

Some vagus devices were “approved” through the FDA’s most stringent type of review⁶. Others were “cleared” through a different path, which our device article explains.

Implanted stimulation for epilepsy. A small generator placed under the skin of the upper left chest sends pulses through a wire to the left vagus nerve in the neck⁵. It has been used for hard-to-control epilepsy since 1997⁷.

Implanted stimulation for depression. The FDA approved the same kind of device in July 2005 for depression that hadn’t responded to standard treatment⁷. The approval covers episodes that have failed at least four adequate trials of medicines or electroconvulsive therapy⁵.

The evidence is mixed. In a 235-patient trial against a sham device, response after three months was 15% versus 10%, a difference too small to rule out chance⁵. Benefits grew over a year in open-label follow-up, where everyone knew they had the real device⁵. To reach its decision, the FDA accepted a comparison with a matched group of patients who were not randomly assigned⁵.

A 2006 review of the depression evidence was supported by an educational grant from Cyberonics, the device’s maker⁷. Common side effects include a hoarse voice, cough and shortness of breath while the device is firing⁵.

Stroke rehabilitation. The Vivistim system, from MicroTransponder, is meant for people whose arm stays moderately to severely weak long after an ischemic stroke, the kind caused by a blocked blood vessel⁶. The implant pairs vagus nerve stimulation with rehab exercises, and the FDA approved it on Aug. 27, 2021⁶.

The gains in its pivotal trial of 108 people were real but modest. At 90 days, about twice as many treated patients as controls had improved at least 6 points on a standard arm-function scale, 47.2% versus 23.6%; the average gain was about 5 points versus 2.4⁶. Reported side effects included hoarseness, trouble speaking, throat irritation, dizziness and falls⁶.

Headache. gammaCore is a handheld stimulator placed on the neck over the vagus nerve. Its maker, electroCore, announced in November 2018 that the FDA had cleared it as an add-on treatment to help prevent cluster headache in adults¹³. The company said it was already cleared for acute treatment of pain from episodic cluster headache and migraine¹³. That account comes from the company’s announcement.

Each of these devices was tested for a specific disease, and most need surgery. None shows that a gadget can fix everyday stress.

Humming, gargling and cold water: rating the vagus hacks

Social media sells humming, gargling, cold plunges and ear massage as ways to “tone” the vagus nerve.

Slow breathing has the best case. Your heart rate already rises and falls with each breath through vagal control⁹. Slow, steady breathing builds on that link and is the basis of HRV biofeedback. Our HRV and sleep-relaxation articles rate slow breathing for stress and sleep as promising but early.

Humming and chanting. They stretch out each exhale, so they may work partly through that same breathing link. Many traditions pair long breaths with sound, from Hindu mantra chanting to sung prayer, and these practices can be meaningful. But we found no good trials showing that humming itself improves health. Rating: Not enough evidence.

Gargling. We found no controlled trials at all. Rating: Not enough evidence.

Cold water. Cold plunges are often pitched as instant vagus resets. We don’t recommend cold shock as a way to calm down; our cold plunge article covers what cold water can and can’t do. Rating as a calming tool: Not enough evidence.

Neck and ear gadgets. A device cleared for headache has evidence for that use, not for stress¹³. Clip-on ear stimulators, which target a small vagus branch in the outer ear, are at an earlier stage.

A 2021 systematic review in Frontiers in Neuroscience found 41 randomized trials of ear stimulation, but only 2 of the 38 papers earned a low risk-of-bias rating, and it judged the evidence low in quality overall¹². It saw early hints of benefit for pain and inflammation, and conflicting results on heart rate variability¹².

One co-author was affiliated with LivaNova, a maker of implanted vagus stimulators¹². Rating for ear stimulation: Promising but early.

Myths and facts about your autonomic nervous system

Claim	Myth or fact?	What the evidence shows	Rating
A simple maneuver can stop some racing heart rhythms	Fact, with medical guidance	U.S. guideline’s top recommendation2; leg-raise version: 43% vs. 17% in a 428-person ER trial1	Strong evidence for vagal maneuvers; the leg-raise version rests mainly on one large trial
Ear stimulators calm the nervous system	Unproven	41 trials, most at some or high risk of bias; heart rate variability results conflict12	Promising but early
Implanted VNS treats hard-to-treat depression	Partly true	FDA approved, but no clear edge over a sham device at three months5	Promising but early
Polyvagal theory is settled science	Myth	39 experts call its core wiring claims unsupported; its author disputes that1011	Not enough evidence for its specific vagal claims
Humming or gargling “tones” your vagus nerve	Untested	No good trials found	Not enough evidence
Breathing changes your heart rhythm	Fact	Heart rate rises and falls with each breath through vagal control9	Strong evidence for the effect on heart rhythm
Dizziness when you stand is “just stress”	Myth	It can signal a blood pressure drop from autonomic nerve problems3	See a clinician

A calming list, rated, with where to read more

Each has been reviewed in another article in our library.

1. Slow breathing, about six breaths a minute. Try breathing in for about 4 seconds and out for about 6. Rated promising but early for stress and, before bed, for self-rated sleep. Read our HRV article and “The Viral ‘Military Sleep Method’ Hasn’t Been Tested in Trials. Older Relaxation Methods Have.”
2. Regular exercise. Rated strong evidence for easing anxiety symptoms. Read “Moving can ease anxiety, though viral shaking and somatic workouts are less proven.”
3. Mindful walking. Rated promising but early for stress and low mood. Read “Mindful walking eased stress in small trials, and the walking itself deserves some credit.”
4. Tai chi. Slow movement paired with steady breath. Rated promising but early for blood pressure and sleep. Read “Tai chi began as a martial art, and its best-proven use is preventing falls.”
5. A mindfulness course. Rated strong evidence for modestly easing anxiety. Read “What Meditation Groups Can Do, and What They Can Stir Up.”

If a practice makes you dizzy, short of breath or more anxious, stop and return to normal breathing.

When the autopilot really fails: dysautonomia and POTS

Doctors use the umbrella term dysautonomia for autonomic trouble⁴. Usually one branch underperforms, though NINDS notes the system can also overreact⁴. Some forms stay local while others involve the whole body; some, as after Guillain-Barré syndrome, a sudden inflammation of the nerves, can reverse, while others worsen over years⁴.

Many cases ride along with another illness, such as diabetes, heavy drinking, Parkinson’s disease or multiple system atrophy³⁴.

Postural orthostatic tachycardia syndrome, or POTS, makes standing up hard to tolerate: rising from lying down sets the heart racing¹⁴. Dizziness and fainting are the hallmark symptoms, along with fatigue, a pounding heartbeat, trouble concentrating and stomach upset, says NIH’s Genetic and Rare Diseases Information Center (GARD)¹⁴. Most people diagnosed are women ages 15 to 50, and symptoms often start after pregnancy, major surgery, an injury or a viral illness¹⁴.

A clinician may compare your blood pressure and heart rate lying down, sitting and standing, and may order tests of sweating and heart-rate control³.

Most dysautonomia can’t be cured, NINDS says, though forms caused by another disease may ease when that disease is treated⁴. If your blood pressure sags when you stand, a clinician may suggest sleeping with the head raised, compression stockings or more salt, and sometimes fludrocortisone or midodrine³⁴.

For POTS, GARD says no single treatment works for everyone; fluids, salt and exercise are common starting points¹⁴. Make any of these changes with your clinician.

Questions readers ask

The bottom line

Your autonomic nervous system is real, measurable and worth respecting. The vagus nerve is the target of FDA-approved and FDA-cleared treatments, and vagal maneuvers can stop some racing heart rhythms.

Most viral hacks haven’t been tested, and polyvagal theory’s wiring claims face serious scientific challenge. Slow breathing, movement and rest are the best-supported ways to work with your body’s brake. Real autonomic symptoms, like fainting when you stand, deserve a medical visit, not a hack.

Related reading

• Your HRV is personal and noisy, so read the trend rather than the day
• Your gut and brain really talk, but many mood claims started in mice
• “FDA registered” isn’t “FDA approved”: a buyer’s map to wellness devices
• A cold plunge eases soreness but can shrink your muscle gains
• Moving can ease anxiety, though viral shaking and somatic workouts are less proven

Sources

1. National Institute for Health and Care Research. “A New Simple Postural Manoeuvre Can Stop an Abnormally Fast Heart Rate” (summary of Appelboam A, Reuben A, Mann C, et al., The Lancet, 2015). NIHR Evidence. evidence.nihr.ac.uk
2. American College of Cardiology, American Heart Association and Heart Rhythm Society. “2015 ACC/AHA/HRS Guideline for the Management of Adult Patients With Supraventricular Tachycardia.” Published September 23, 2015 (AHA guideline slide set). professional.heart.org
3. MedlinePlus. “Autonomic Neuropathy.” U.S. National Library of Medicine, reviewed 2024. medlineplus.gov
4. National Institute of Neurological Disorders and Stroke. “Dysautonomia” (NINDS disorder information, via BrainFacts.org). brainfacts.org
5. Janicak PG, Dowd SM, Rado JT, Welch MJ. “The Re-Emerging Role of Therapeutic Neuromodulation.” Current Psychiatry, 2010;9(11):67-74. cdn.mdedge.com
6. U.S. Food and Drug Administration. “FDA Approves First-of-Its-Kind Stroke Rehabilitation System.” News release, Aug. 27, 2021 (via BioSpace). biospace.com
7. Nemeroff CB, Mayberg HS, Krahl SE, et al. “VNS Therapy in Treatment-Resistant Depression: Clinical Evidence and Putative Neurobiological Mechanisms.” Neuropsychopharmacology, 2006;31(7):1345-1355. experts.umn.edu
8. Porges SW. “The Vagal Paradox” (Polyvagal Institute statement by the theory’s originator). Polyvagal Institute, 2026.
9. Giroux C, Ahlers D, Miawotoe A. “Polyvagal Approaches: Scientifically Questionable but Useful in Practice.” Journal of Psychiatry Reform, 2023;10(11). journalofpsychiatryreform.com
10. Grossman P, et al. “Why the Polyvagal Theory Is Untenable: An International Expert Evaluation of the Polyvagal Theory.” Clinical Neuropsychiatry, 2026;23(1):100-112. clinicalneuropsychiatry.org
11. Porges SW. “When a Critique Becomes Untenable: A Scholarly Response to Grossman et al.’s Evaluation of Polyvagal Theory.” Clinical Neuropsychiatry, 2026. clinicalneuropsychiatry.org
12. Verma N, Mudge JD, Kasole M, et al. “Auricular Vagus Neuromodulation: A Systematic Review on Quality of Evidence and Clinical Effects.” Frontiers in Neuroscience, 2021;15:664740. frontiersin.org
13. electroCore Inc. Press release on FDA 510(k) clearance for cluster headache prevention, Nov. 28, 2018 (SEC Form 8-K, Exhibit 99.1; company announcement). sec.gov
14. Genetic and Rare Diseases Information Center (GARD). “Síndrome de taquicardia postural ortostática” (postural orthostatic tachycardia syndrome). National Institutes of Health, Spanish-language page, updated January 23, 2017. rarediseases.info.nih.gov
15. MedlinePlus. “Stress and Your Health.” U.S. National Library of Medicine, reviewed 2026. medlineplus.gov