AzTrials
AzTrials

Healthy VolunteerstaVNS-FREQNCT07526402

Different Frequency Applications of Transcutaneous Auricular Vagus Nerve Stimulation in Healthy Individuals

A study testing taVNS 10 Hz, taVNS 25 Hz and taVNS 50 Hz 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
Search all trials

Trial summary

This randomized, participant-blinded, sham-controlled crossover study aims to investigate the acute effects of different frequency applications of transcutaneous auricular vagus nerve stimulation (taVNS) on autonomic physiological 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?
taVNS 10 Hz, taVNS 25 Hz and taVNS 50 Hz
Type of treatment
Medical device
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
36 participants
Where
1 siteTurkey (Türkiye)
Study dates
1 May 2026to 1 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 neurological, cardiovascular, respiratory, or metabolic disease
  • Able to understand study procedures and provide written informed consent
  • No active infection, open wound, or dermatological lesion in the ear region that would interfere with taVNS application
  • Willing and able to attend all study visits

Who cannot join

  • History of cardiac arrhythmia, pacemaker, or any implanted electronic medical device History of hypertension, diabetes, chronic pulmonary disease, epilepsy, or systemic disease affecting autonomic nervous system function
  • Regular use of medications that may affect autonomic function (e.g., beta-blockers, antidepressants, antiarrhythmics)
  • Intense physical exercise within the previous 24 hours
  • High caffeine or alcohol intake within 12 hours prior to assessment
  • Active smoking on the assessment day
  • Pregnancy or suspected pregnancy
  • Severe discomfort during stimulation (VAS >= 7), dizziness, nausea, or unwillingness to continue
  • Any condition judged by the investigators to make participation unsuitable'

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, MSc, 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, PT, MSc, +90 541523 36 91, omerdiclekizil@gmail.com

    Ömer Dicle Kızıl, PT, MSc

Other trials in Turkey (Türkiye)

About this study

Official title: Investigation of the Acute Effects of Different Frequency Applications of Transcutaneous Auricular Vagus Nerve Stimulation on Autonomic Physiological Responses in Healthy Individuals

This randomized, participant-blinded, sham-controlled crossover study aims to investigate the acute effects of different frequency applications of transcutaneous auricular vagus nerve stimulation (taVNS) on autonomic physiological responses in healthy adults. Participants will receive sham (0 Hz), 10 Hz, 25 Hz, 50 Hz, and 100 Hz taVNS in separate sessions with washout periods between visits. Heart rate variability, blood pressure, pulse rate, respiratory rate, and subjective discomfort will be assessed before and after each intervention session.

Read the detailed description

The vagus nerve is a major regulator of the parasympathetic branch of the autonomic nervous system. Transcutaneous auricular vagus nerve stimulation (taVNS) is a non-invasive neuromodulation technique applied to auricular regions innervated by the auricular branch of the vagus nerve. Although taVNS has been reported to modulate autonomic function, the acute physiological effects of different stimulation frequencies remain insufficiently characterized.

This study is designed as a randomized, participant-blinded, sham-controlled crossover trial in healthy adults aged 18 to 40 years. Each participant will undergo five intervention conditions in randomized order: sham (0 Hz), 10 Hz, 25 Hz, 50 Hz, and 100 Hz taVNS. Sessions will be separated by 48 to 72 hours to minimize carryover effects. Each stimulation session will last 10 minutes.

Primary autonomic outcomes will be derived from heart rate variability parameters obtained using a Polar H10 chest strap and analyzed with Kubios HRV software. Secondary physiological outcomes will include systolic and diastolic blood pressure, pulse rate, respiratory rate, and subjective discomfort measured using a visual analog scale. The study aims to identify frequency-specific autonomic response profiles and to evaluate whether respiratory rate influences heart rate variability changes associated with taVNS.

Being tested
Sham taVNS, taVNS 10 Hz, taVNS 25 Hz, taVNS 50 Hz, taVNS 100 Hz

What participants receive

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

  • Sham taVNSDevice

    Sham stimulation is delivered under conditions similar to active taVNS without meaningful vagal stimulation.

  • taVNS 10 HzDevice

    Active transcutaneous auricular vagus nerve stimulation applied for 10 minutes at 10 Hz.

  • taVNS 25 HzDevice

    Active transcutaneous auricular vagus nerve stimulation applied for 10 minutes at 25 Hz.

  • taVNS 50 HzDevice

    Active transcutaneous auricular vagus nerve stimulation applied for 10 minutes at 50 Hz.

  • taVNS 100 HzDevice

    Active transcutaneous auricular vagus nerve stimulation applied for 10 minutes at 100 Hz.

Study groups in NCT07526402
Study groupRoleWhat they receive
Sham taVNSSham comparatorParticipants receive sham stimulation during one study session.
Receives: Device: Sham taVNS
taVNS 10 HzExperimentalParticipants receive active transcutaneous auricular vagus nerve stimulation at 10 Hz during one study session.
Receives: Device: taVNS 10 Hz
taVNS 25 HzExperimentalParticipants receive active transcutaneous auricular vagus nerve stimulation at 25 Hz during one study session.
Receives: Device: taVNS 25 Hz
taVNS 50 HzExperimentalParticipants receive active transcutaneous auricular vagus nerve stimulation at 50 Hz during one study session.
Receives: Device: taVNS 50 Hz
taVNS 100 HzExperimentalParticipants receive active transcutaneous auricular vagus nerve stimulation at 100 Hz during one study session.
Receives: Device: taVNS 100 Hz

What is being measured

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

  1. Change in Root Mean Square of Successive Differences (RMSSD)

    Change in the root mean square of successive differences (RMSSD) from pre-intervention to post-intervention under each stimulation condition.

    Measured: Immediately before and immediately after each 10-minute intervention session

  2. Change in High-Frequency Heart Rate Variability (HF-HRV)

    Change in high-frequency heart rate variability (HF-HRV) from pre-intervention to post-intervention under each stimulation condition.

    Measured: Immediately before and immediately after each 10-minute intervention session

Secondary outcomes (8)

  1. Change in Standard Deviation of Normal-to-Normal RR Intervals (SDNN)

    Change in the standard deviation of normal-to-normal RR intervals (SDNN) from pre-intervention to post-intervention under each stimulation condition.

    Measured: Immediately before and immediately after each 10-minute intervention session

  2. Change in Low-Frequency (LF) Power

    Change in low-frequency (LF) power of heart rate variability from pre-intervention to post-intervention under each stimulation condition.

    Measured: Immediately before and immediately after each 10-minute intervention session

  3. Change in LF/HF Ratio

    Change in the ratio of low-frequency to high-frequency heart rate variability (LF/HF ratio) from pre-intervention to post-intervention under each stimulation condition.

    Measured: Immediately before and immediately after each 10-minute intervention session

  4. Change in Systolic Blood Pressure

    Change in systolic blood pressure from pre-intervention to post-intervention under each stimulation condition.

    Measured: Immediately before and immediately after each 10-minute intervention session

  5. Change in Diastolic Blood Pressure

    Change in diastolic blood pressure from pre-intervention to post-intervention under each stimulation condition.

    Measured: Immediately before and immediately after each 10-minute intervention session

  6. Change in Pulse Rate

    Change in pulse rate from pre-intervention to post-intervention under each stimulation condition.

    Measured: Immediately before and immediately after each 10-minute intervention session

  7. Change in Respiratory Rate

    Change in respiratory rate from pre-intervention to post-intervention under each stimulation condition.

    Measured: Immediately before and immediately after each 10-minute intervention session

  8. Change in Subjective Discomfort Assessed by Visual Analog Scale (VAS)

    Subjective discomfort will be assessed using a Visual Analog Scale (VAS) ranging from 0 to 10, where 0 indicates no discomfort and 10 indicates the worst possible discomfort. Higher scores indicate greater discomfort. Change in VAS score from pre-intervention to post-intervention will be evaluated under each stimulation condition.

    Measured: Immediately before and immediately after each 10-minute intervention session

Timeline

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

  1. First posted13 Apr 2026
  2. Study start1 May 2026 (estimated)
  3. Primary completion1 May 2026 (estimated)
  4. Study completion1 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
Crossover
Model description
Each participant will receive all five intervention conditions (sham, 10 Hz, 25 Hz, 50 Hz, and 100 Hz taVNS) in randomized order across separate visits, with a 48- to 72-hour washout period between sessions.
Masking
Single blind
Who is masked
Participant
Enrolment
36 participants (estimated)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07526402
Sponsor's protocol ID
TAVNS4
Acronym
taVNS-FREQ
Status last verified
Apr 2026
First submitted
6 Apr 2026
Last updated
16 Apr 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Publications

  • Shaffer F, Ginsberg JP. An Overview of Heart Rate Variability Metrics and Norms. Front Public Health. 2017 Sep 28;5:258. doi: 10.3389/fpubh.2017.00258. eCollection 2017.

    PubMed 29034226

  • Yakunina N, Kim SS, Nam EC. Optimization of Transcutaneous Vagus Nerve Stimulation Using Functional MRI. Neuromodulation. 2017 Apr;20(3):290-300. doi: 10.1111/ner.12541. Epub 2016 Nov 29.

    PubMed 27898202

  • Peuker ET, Filler TJ. The nerve supply of the human auricle. Clin Anat. 2002 Jan;15(1):35-7. doi: 10.1002/ca.1089.

    PubMed 11835542

  • 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

Questions about this trial

What is this clinical trial studying?

A study testing taVNS 10 Hz, taVNS 25 Hz and taVNS 50 Hz 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 5 inclusion and 8 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 16 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, MSc, 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 Root Mean Square of Successive Differences (RMSSD) (time frame: Immediately before and immediately after each 10-minute intervention session). 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 NCT07526402, which also lists 4 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 16 Apr 2026.

AzTrials uses cookies for analytics and advertising. You can accept or reject them; the site works either way. Privacy Policy.

Free account

Log in to keep searching

You’ve used your 3 free searches. AzTrials is free: log in or create a free account to keep searching clinical trials and save the ones you want to follow.

Create a free accountLog in