taVNS Reduces Pain, Improves Mood in Fibromyalgia Patients

A recent study showed that both left and bilateral Transcutaneous Auricular Vagus Nerve Stimulation (taVNS) reduced pain and improved mood and functioning in patients with fibromyalgia.1

Fibromyalgia Syndrome symptoms, including widespread pain, fatigue, emotional disturbances, and autonomic dysfunction, can be managed with taVNS. Patients can either receive left and bilateral taVNS, both noninvasive options.

In the past, it was advised to target the left vagus nerve to avoid the potential risk of heart-related complications.2 This concern was due to the right vagus nerve having more direct innervation of the sinoatrial node, which regulates heart rhythm. Experts raised concerns that right taVNS could interfere with the heart’s electrical system.

However, more research showed that stimulating the right side is not any more dangerous than stimulating the left side. A 2018 study found no adverse cardiovascular effects with right-sided or bilateral stimulation.3 Another study in 2020 reported no bradycardia or cardiac distress in patients receiving cervical VNS on the right side.4

Research may confirm that both left and bilateral taVNS are viable treatment options, but it is not known which one is better for treating fibromyalgia. In this study, Mustafa Ferit Akkurt, PhD, from the department of occupational therapy at Fenerbahce University in Turkey, and colleagues, sought to compare the effects of left and bilateral taVNS on pain, mood, functionality, and autonomic nervous system activity in individuals with fibromyalgia.1

The study included 40 females with fibromyalgia, assigned to receive either left (n = 20) or bilateral (n = 20) taVNS. In both groups, participants received 11 taVNS sessions targeting the tragus and concha regions over nonconsecutive days, excluding weekends and menstrual periods. Each session lasted 30 minutes each, 25 Hz, 300 µs.

The team assessed the Visual Analog Scale (VAS), the Beck Depression Inventory (BDI), the Beck Anxiety Inventory (BAI), and the Fibromyalgia Impact Questionnaire (FIQ). They also evaluated autonomic nervous system activity via heart rate variability. The study included a 2-week follow-up after the 11 sessions.

The study only observed significant differences between left and bilateral taVNS for the Fibromyalgia Impact Questionnaire and the Beck Anxiety Inventory on day 28 (P =.002 to 0.008). Both arms demonstrated significant within-group improvements in the Visual Analog Scale (P <.001), Fibromyalgia Impact Questionnaire (P <.001), Beck Depression Inventory (P <.001), and Beck Anxiety Inventory (P <.001). There were no significant between-group differences for parasympathetic nervous system (P =.365 to 0.776) and sympathetic nervous system (P =.598 to 0.880) indices, 2 sub-parameters of heart rate variability.1

“Both stimulation protocols effectively reduced pain and improved mood and functionality in fibromyalgia, indicating a safe, noninvasive adjunctive treatment option,” investigators concluded.

This study conflicts with a previous study published in 2024 that did not show the benefit of taVNS for reducing fibromyalgia pain.5 However, investigators of that study noted that this warranted future research due to its small sample size. This study had assessed the effect of taVNS and tcNS on chronic pain using 15 studies, and only 6 focused on taVNS.

In another report, an invasive VNS led to 5 out of 11 patients with fibromyalgia no longer meeting the diagnosis criteria after 11 months of treatment.6 Furthermore, a study on taVNS in conjunction with exercise found that taVNS significantly reduced the VAS scores in patients with fibromyalgia, but there was no significant difference between the control group (exercise only) and the treatment group.7

Akkurt and colleagues’ study reinforces that both left and bilateral taVNS can safely reduce pain and improve mood and functionality in patients with fibromyalgia, highlighting its potential as a noninvasive adjunctive therapy.

References

1. Akkurt MF, Özden AV, Akkurt HE, Akkurt B, Bildik C. Effects of left and bilateral transcutaneous auricular vagus nerve stimulation on pain, mood, and autonomic nervous system in female patients with fibromyalgia: a randomized controlled trial. Physiother Theory Pract. Published online December 2, 2025. doi:10.1080/09593985.2025.2594572

2. Do You Really Have to Avoid Stimulating the Right Side of the Vagus Nerve? Hoolest. Accessed December 19, 2025. https://hoolest.com/blogs/news/do-you-really-have-to-avoid-stimulating-the-right-side-of-the-vagus-nerve?srsltid=AfmBOoqBgQubc8OpELYeoPTpeVH8h2i-UwWhQPcSxjBN4CfYNkjQCEIE

3. Badran, B. W., Dowdle, L. T., Mithoefer, O. J., Labate, N. T., Coatsworth, J., Brown, J. C., ... & George, M. S. (2018). Neurophysiologic effects of transcutaneous auricular vagus nerve stimulation (taVNS). Brain Stimulation, 11(3), 492-500.

4. Goyal, M., Goyal, K., Patnaik, A., Mahapatra, A. K., & Singh, J. P. (2020). Non-invasive Vagus Nerve Stimulation for the Management of Epilepsy. Frontiers in Neurology, 11, 578965.

5. Costa V, Gianlorenço AC, Andrade MF, et al. Transcutaneous vagus nerve stimulation effects on chronic pain: systematic review and meta-analysis. Pain Rep. 2024;9(5):e1171. Published 2024 Aug 7. doi:10.1097/PR9.0000000000001171

6. Lange G, Janal MN, Maniker A, et al. Safety and efficacy of vagus nerve stimulation in fibromyalgia: a phase I/II proof of concept trial. Pain Med. 2011;12(9):1406-1413. doi:10.1111/j.1526-4637.2011.01203.x

7. Kutlu N, Özden AV, Alptekin HK, Alptekin JÖ. The Impact of Auricular Vagus Nerve Stimulation on Pain and Life Quality in Patients with Fibromyalgia Syndrome. Biomed Res Int. 2020;2020:8656218. Published 2020 Feb 28. doi:10.1155/2020/8656218