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Healthy VolunteerstaVNS-DURNCT07532005

Non-Invasive Transcutaneous Auricular Vagus Nerve Stimulation Applied at Different Durations in Healthy Adults

A study testing Active taVNS in people with Healthy Volunteers, run by Sinop University at 1 site in Turkey (Türkiye).

Not yet recruiting

Opening soon. The study is approved but enrolment has not started yet. Sites may already take enquiries.

Sites and contacts
Official record
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Trial summary

This randomized, participant-blinded, sham-controlled interventional study aims to compare the acute effects of non-invasive transcutaneous auricular vagus nerve stimulation (taVNS) applied at different durations on autonomic nervous system responses in healthy adults. Read more about this study

Who is it for?
Ages 18 to 40 yearsHealthy volunteers can take part
Conditions the study is for
Healthy Volunteers
What is being tested?
Active taVNS
Type of treatment
Medical device
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
44 participants
Where
1 siteTurkey (Türkiye)
Study dates
1 May 2026to 15 Sep 2026
Phase
Interventional
Are there results?
Not yet: the study is under way

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 40 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • Healthy adults aged 18 to 40 years No known chronic systemic disease Non-smoker No regular medication use, including medications that may affect autonomic or cardiovascular function Able to understand the study procedures and provide written informed consent Willing to comply with study instructions and restrictions related to caffeine, alcohol, and strenuous exercise

Who cannot join

  • Any known chronic systemic disease Current smoker Regular medication use, including medications that may affect autonomic or cardiovascular function Inability to understand the study procedures or provide written informed consent Unwillingness or inability to comply with study instructions and restrictions related to caffeine, alcohol, and strenuous exercise

Trial locations and contacts

1 site in 1 country. Contact the study team or a site near you to ask about taking part.

Sefa Haktan Hatık Assistant professor, PhD contact

+90 368 271 55 28

haktanhtk@gmail.com

Turkey (Türkiye)1 site
  • Artvin Coruh University, Artvin Vocational School, Disabled Care and Rehabilitation Laboratory

    Artvin

    Ömer Dicle Kızıl, MSc, omerdiclekizil@gmail.com

    Ömer Dicle Kızıl, MSc

Other trials in Turkey (Türkiye)

About this study

Official title: Comparison of the Acute Effects of Non-Invasive Transcutaneous Auricular Vagus Nerve Stimulation Applied at Different Durations on the Autonomic Nervous System in Healthy Adults: A Sham-Controlled Study

This randomized, participant-blinded, sham-controlled interventional study aims to compare the acute effects of non-invasive transcutaneous auricular vagus nerve stimulation (taVNS) applied at different durations on autonomic nervous system responses in healthy adults. Participants will be assigned to either an active taVNS group or a sham stimulation group. Within each group, participants will complete three separate study visits in which stimulation will be applied for 5, 10, and 15 minutes in randomized order, with 48- to 72-hour washout intervals between visits. Heart rate variability, heart rate, blood pressure, respiratory rate, and subjective discomfort will be assessed immediately before and after each intervention session. The study is designed to determine whether the acute autonomic effects of taVNS vary according to stimulation duration and whether a duration-related response pattern can be identified.

Read the detailed description

Transcutaneous auricular vagus nerve stimulation (taVNS) is a non-invasive neuromodulation method in which electrical stimulation is applied to auricular regions innervated by the auricular branch of the vagus nerve. Because of its low-risk profile, non-surgical application, and potential autonomic regulatory effects, taVNS has attracted increasing interest in autonomic physiology and cardiovascular research.

Previous studies in healthy individuals suggest that taVNS may influence autonomic balance, particularly through changes in heart rate variability (HRV), heart rate, and related physiological parameters. However, substantial heterogeneity remains across published taVNS studies with regard to stimulation parameters such as frequency, pulse width, current intensity, and intervention duration. Among these parameters, stimulation duration is one of the least standardized, and sham-controlled comparisons of different application durations remain limited.

This study is designed to investigate whether the acute autonomic effects of taVNS differ according to stimulation duration. The study uses a randomized, participant-blinded, sham-controlled mixed design. Healthy adults aged 18 to 40 years will be randomized to either an active taVNS group or a sham stimulation group. Participants will remain in their assigned group throughout the study. Within each group, each participant will attend three separate visits and receive stimulation for 5, 10, and 15 minutes in randomized order. Visits will be separated by 48- to 72-hour washout intervals.

Active taVNS will be applied bilaterally to the cymba conchae region using non-invasive stimulation parameters consistent with the study protocol. Sham stimulation will be delivered under visually and procedurally similar conditions to minimize expectancy effects. Before and immediately after each intervention session, autonomic and physiological outcomes will be assessed, including heart rate variability derived from RR interval recordings, heart rate, systolic and diastolic blood pressure, respiratory rate, and subjective discomfort measured by a visual analog scale.

The primary objective is to compare the acute autonomic responses to active taVNS and sham stimulation across different stimulation durations. The study also aims to explore whether a duration-response relationship exists for autonomic outcomes in healthy adults. Findings from this trial may help inform duration selection in future experimental and clinical taVNS research.

Being tested
Active taVNS, Sham stimulation
Keywords
Transcutaneous Auricular Vagus Nerve Stimulation, Sham Stimulation, Autonomic Nervous System

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Active taVNSDevice

    Active transcutaneous auricular vagus nerve stimulation will be applied bilaterally to the cymba conchae region. Stimulation frequency will be 25 Hz, pulse width 200 to 300 microseconds, and intensity will be individually adjusted to a clearly perceptible but comfortable level. Depending on the study visit, stimulation will be delivered for 5, 10, or 15 minutes.

  • Sham stimulationDevice

    Sham stimulation will be delivered using the same device under visually similar conditions. The sham procedure will be applied at a non-vagal auricular site or with minimal non-therapeutic stimulation, depending on the study protocol, for 5, 10, or 15 minutes according to the study visit.

Study groups in NCT07532005
Study groupRoleWhat they receive
Active taVNSExperimentalParticipants assigned to this arm will receive active transcutaneous auricular vagus nerve stimulation during three separate study visits. Stimulation will be applied for 5, 10, and 15 minutes in randomized order, with 48- to 72-hour washout intervals between visits.
Receives: Device: Active taVNS
Sham stimulationSham comparatorParticipants assigned to this arm will receive sham stimulation during three separate study visits. Sham stimulation will be applied for 5, 10, and 15 minutes in randomized order, with 48- to 72-hour washout intervals between visits.
Receives: Device: Sham stimulation

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Change in RMSSD

    Change in the root mean square of successive differences (RMSSD), derived from RR interval recordings, from pre-intervention (T0) to post-intervention (T1) after active taVNS or sham stimulation at 5, 10, and 15 minutes.

    Measured: [Time Frame: Baseline (pre-intervention) and immediately after intervention, at each study visit (5, 10, and 15 minutes)]

  2. Change in high-frequency heart rate variability (HF-HRV)

    Change in high-frequency heart rate variability (HF-HRV) from pre-intervention (T0) to post-intervention (T1) after active taVNS or sham stimulation at 5, 10, and 15 minutes.

    Measured: [Time Frame: Baseline (pre-intervention) and immediately after intervention, at each study visit (5, 10, and 15 minutes)]

Secondary outcomes (7)
  1. Change in heart rate

    Change in heart rate from pre-intervention to post-intervention after active taVNS or sham stimulation at each study visit.

    Measured: [Time Frame: Baseline (pre-intervention) and immediately after intervention, at each study visit (5, 10, and 15 minutes)]

  2. Change in systolic blood pressure

    Change in systolic blood pressure from pre-intervention to post-intervention after active taVNS or sham stimulation at each study visit.

    Measured: [Time Frame: Baseline (pre-intervention) and immediately after intervention, at each study visit (5, 10, and 15 minutes)]

  3. Change in diastolic blood pressure

    Change in diastolic blood pressure from pre-intervention to post-intervention after active taVNS or sham stimulation at each study visit.

    Measured: [Time Frame: Baseline (pre-intervention) and immediately after intervention, at each study visit (5, 10, and 15 minutes)]

  4. Change in respiratory rate

    Change in respiratory rate from pre-intervention to post-intervention after active taVNS or sham stimulation at each study visit.

    Measured: [Time Frame: Baseline (pre-intervention) and immediately after intervention, at each study visit (5, 10, and 15 minutes)]

  5. Change in subjective discomfort assessed by visual analog scale (VAS)

    Change in subjective discomfort assessed by visual analog scale (VAS) from pre-intervention to post-intervention after active taVNS or sham stimulation at each study visit.

    Measured: [Time Frame: Baseline (pre-intervention) and immediately after intervention, at each study visit (5, 10, and 15 minutes)]

  6. Change in SDNN

    Change in the standard deviation of normal-to-normal intervals (SDNN) from pre-intervention to post-intervention after active taVNS or sham stimulation at each study visit.

    Measured: [Time Frame: Baseline (pre-intervention) and immediately after intervention, at each study visit (5, 10, and 15 minutes)]

  7. Change in LF/HF ratio

    Change in the low-frequency/high-frequency ratio (LF/HF ratio) from pre-intervention to post-intervention after active taVNS or sham stimulation at each study visit.

    Measured: [Time Frame: Baseline (pre-intervention) and immediately after intervention, at each study visit (5, 10, and 15 minutes)]

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted15 Apr 2026
  2. Study start1 May 2026 (estimated)
  3. Primary completion31 Aug 2026 (estimated)
  4. Study completion15 Sep 2026 (estimated)

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Basic science
Allocation
Randomised
Intervention model
Parallel groups
Model description
Participants will be randomized to either an active taVNS group or a sham stimulation group and will remain in their assigned group throughout the study. Within each group, participants will complete three separate visits with stimulation durations of 5, 10, and 15 minutes in randomized order, with 48- to 72-hour washout intervals between visits.
Masking
Single blind
Who is masked
Participant
Enrolment
44 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07532005
Sponsor's protocol ID
TAVNS5
Acronym
taVNS-DUR
Status last verified
Apr 2026
First submitted
6 Apr 2026
Last updated
15 Apr 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • Frangos E, Ellrich J, Komisaruk BR. Non-invasive Access to the Vagus Nerve Central Projections via Electrical Stimulation of the External Ear: fMRI Evidence in Humans. Brain Stimul. 2015 May-Jun;8(3):624-36. doi: 10.1016/j.brs.2014.11.018. Epub 2014 Dec 6.

    PubMed 25573069
  • Farmer AD, Strzelczyk A, Finisguerra A, Gourine AV, Gharabaghi A, Hasan A, Burger AM, Jaramillo AM, Mertens A, Majid A, Verkuil B, Badran BW, Ventura-Bort C, Gaul C, Beste C, Warren CM, Quintana DS, Hammerer D, Freri E, Frangos E, Tobaldini E, Kaniusas E, Rosenow F, Capone F, Panetsos F, Ackland GL, Kaithwas G, O'Leary GH, Genheimer H, Jacobs HIL, Van Diest I, Schoenen J, Redgrave J, Fang J, Deuchars J, Szeles JC, Thayer JF, More K, Vonck K, Steenbergen L, Vianna LC, McTeague LM, Ludwig M, Veldhuizen MG, De Couck M, Casazza M, Keute M, Bikson M, Andreatta M, D'Agostini M, Weymar M, Betts M, Prigge M, Kaess M, Roden M, Thai M, Schuster NM, Montano N, Hansen N, Kroemer NB, Rong P, Fischer R, Howland RH, Sclocco R, Sellaro R, Garcia RG, Bauer S, Gancheva S, Stavrakis S, Kampusch S, Deuchars SA, Wehner S, Laborde S, Usichenko T, Polak T, Zaehle T, Borges U, Teckentrup V, Jandackova VK, Napadow V, Koenig J. International Consensus Based Review and Recommendations for Minimum Reporting Standards in Research on Transcutaneous Vagus Nerve Stimulation (Version 2020). Front Hum Neurosci. 2021 Mar 23;14:568051. doi: 10.3389/fnhum.2020.568051. eCollection 2020.

    PubMed 33854421
  • Clancy JA, Mary DA, Witte KK, Greenwood JP, Deuchars SA, Deuchars J. Non-invasive vagus nerve stimulation in healthy humans reduces sympathetic nerve activity. Brain Stimul. 2014 Nov-Dec;7(6):871-7. doi: 10.1016/j.brs.2014.07.031. Epub 2014 Jul 16.

    PubMed 25164906

Questions about this trial

What is this clinical trial studying?

A study testing Active taVNS in people with Healthy Volunteers, run by Sinop University at 1 site in Turkey (Türkiye).

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: opening soon, as of the sponsor's last update on 15 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

This study is still under way. Results are not available in the source record yet.

How can a doctor refer a patient or contact the research team?

Contact Sefa Haktan Hatık Assistant professor, PhD (+90 368 271 55 28, haktanhtk@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Change in RMSSD (time frame: [Time Frame: Baseline (pre-intervention) and immediately after intervention, at each study visit (5, 10, and 15 minutes)]). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT07532005, which also lists 3 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Apr 2026.

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