Vagus Nerve Stimulation: Implanted and Noninvasive
How implanted and noninvasive vagus nerve stimulation differ, which U.S. devices have regulator records for epilepsy, depression, stroke rehabilitation and headache, and what trials show.
Content last updated . This page has not been medically reviewed.
Urgent first
If you or someone you know is struggling or having thoughts of suicide, call or text 988 (the 988 Suicide and Crisis Lifeline, United States) or call 911 in a life-threatening situation. [1] This page is education only. Do not change or stop any treatment because of it.Two different things with one name
The vagus nerve runs from the brainstem through the neck and down the side of the chest and abdomen. [1] Vagus nerve stimulation (VNS) can mean:- Implanted VNS: a surgical procedure in which a pulse generator is implanted in the upper left chest and a lead is connected to the left vagus nerve. [1]
- Noninvasive or transcutaneous VNS (tVNS): a portable device that sends electrical stimulation through the skin. [1]
They are separate technologies with separate evidence and separate regulatory records. A result for one is not a result for the other. For the general landscape, see electrical and magnetic brain stimulation.
Evidence labels (established, promising but limited, mixed, insufficient evidence) are explained in how we label evidence.
What the research shows
Epilepsy (implanted). A Cochrane review of five trials with 439 participants compared higher with lower stimulation and found that high-frequency VNS was over one and a half times more effective than low-frequency VNS for a 50% or greater reduction in seizures. [9] The reviewers note that blinding is difficult because stimulation causes side effects such as voice alteration. [9] Label: approved device with moderate-quality trial evidence for the 50%-responder outcome; the trials compared higher with lower stimulation, not with no device.Depression (implanted). NIMH says VNS is not a first-line treatment and remains infrequently used, and that study results on depression have been mixed. [1] A 2026 systematic review of long-term studies (10 cohort studies and 8 case series) rated the certainty of evidence very low. [10] Label: mixed. Not all people respond, and NIMH notes some get no improvement and some may get worse. [1]
Depression (noninvasive, auricular). A meta-analysis of 12 studies (838 participants) reported lower depression scores, but described the evidence quality as low to very low and the subgroups as small. [11] Label: insufficient evidence, in line with the FDA position above.
Stroke rehabilitation (implanted, paired with therapy). In the VNS-REHAB randomized sham-controlled trial, 108 people were assigned to rehabilitation with active or sham stimulation, all of them implanted. [12] Arm impairment score on the Fugl-Meyer scale improved by 5.0 points with active VNS and 2.4 with sham, a difference of 2.6 (95% CI 1.0 to 4.2). [12] The trial was funded by the device maker. [12] Label: promising but limited; one trial, an impairment scale rather than daily-life function, a modest absolute difference.
Headache (noninvasive). The 2018 migraine submission relied on a multicenter, randomized, double-blind, sham-controlled study at 10 headache centers in Italy. [8] The earlier cluster-headache clearance states that clinical studies were not required to validate the modifications to that device. [6] A clearance is not an endorsement of every claim made for similar handheld devices.
Frequently asked questions
Is vagus nerve stimulation FDA approved?
Specific implanted systems are approved for specific uses: epilepsy, depression and, for a separate system, stroke rehabilitation. [2] [3] [4] The status of one product does not apply to others.
Is noninvasive VNS approved for depression?
NIMH says tVNS is not currently authorized by the FDA as a treatment for depression. [1]
Does VNS cure depression?
No. Results are mixed; NIMH says some people do not improve and some get worse. [1]
What are the side effects?
Voice changes, cough, neck pain and swallowing or breathing difficulty are listed by NIMH, plus surgical complications for implants. [1]
Can I stimulate my vagus nerve at home?
The regulator records here are for specific devices used as labeled. See clinical vs consumer devices and DIY stimulation risks.
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Regulatory records read for this page (United States, 2026-10-22)
| Product and use | What the FDA record says |
|---|---|
| VNS Therapy System, epilepsy | Original PMA P970003 approved July 16, 1997 [2]. A 2017 supplement set the indication as adjunctive therapy to reduce seizure frequency in patients 4 years and older with partial onset seizures that are refractory to antiepileptic medications. [2] |
| VNS Therapy System, depression | Supplement P970003/S50, approval notice July 15, 2005 [3]: adjunctive long-term treatment of chronic or recurrent depression in people 18 and older who have not had an adequate response to four or more adequate antidepressant treatments. [3] |
| Vivistim Paired VNS System, stroke | PMA P210007, approved August 27, 2021; stimulates the vagus nerve during rehabilitation therapy to reduce upper extremity motor deficits in chronic ischemic stroke patients with moderate to severe arm impairment. [4] |
| gammaCore-S (noninvasive), headache | 510(k) cleared with a decision date of May 30, 2017 [5] for the acute treatment of pain associated with episodic cluster headache in adults [6]; a later submission (decision January 23, 2018 [7]) added migraine headache. [8] |
NIMH states that tVNS is not currently authorized by the FDA as a treatment for depression. [1] Rules outside the United States were not verified here.
Risks and who should not use it
- Implant surgery: infection or pain, or a device that comes loose, moves or malfunctions and may need further surgery. [1]
- Common effects: voice changes or hoarseness, cough, neck pain, breathing problems especially during exercise, and difficulty swallowing. [1]
- Long term: the long-term side effects of all forms of VNS are unknown. [1]
- Contraindications in the FDA record: people after a bilateral or left cervical vagotomy cannot use the VNS Therapy System, and shortwave, microwave or therapeutic-ultrasound diathermy is not to be used on implanted patients because of heating risk. [3]
Safety note
References
- National Institute of Mental Health. Brain Stimulation Therapies. Read 2026-10-22.
- U.S. Food and Drug Administration. PMA P970003/S207: Summary of Safety and Effectiveness Data (VNS Therapy System, epilepsy). Read 2026-10-22.
- U.S. Food and Drug Administration. PMA P970003/S50: Summary of Safety and Effectiveness Data (VNS Therapy System, depression). Read 2026-10-22.
- U.S. Food and Drug Administration. PMA P210007: Summary of Safety and Effectiveness Data (Vivistim Paired VNS System). Read 2026-10-22.
- U.S. Food and Drug Administration. 510(k) database record K171306. Read 2026-10-22.
- U.S. Food and Drug Administration. 510(k) summary K171306 (gammaCore-S). Read 2026-10-22.
- U.S. Food and Drug Administration. 510(k) database record K173442. Read 2026-10-22.
- U.S. Food and Drug Administration. 510(k) summary K173442 (gammaCore-S). Read 2026-10-22.
- Panebianco M, et al. Vagus nerve stimulation for partial seizures. Cochrane Database Syst Rev. 2015. Read 2026-10-22.
- Rosson S, et al. Long-term efficacy and safety of vagus nerve stimulation in treatment-resistant depression: A systematic review. J Affect Disord. 2026. Read 2026-10-22.
- Tan C, et al. The efficacy and safety of transcutaneous auricular vagus nerve stimulation in the treatment of depressive disorder: A systematic review and meta-analysis of randomized controlled trials. J Affect Disord. 2023. Read 2026-10-22.
- Dawson J, et al. Vagus nerve stimulation paired with rehabilitation for upper limb motor function after ischaemic stroke (VNS-REHAB): a randomised, blinded, pivotal, device trial. Lancet. 2021. Read 2026-10-22.