Ear vagus‑nerve stimulation for capsaicin-induced and pressure pain
Official title: Exploration of the Effect, and Their Duration, of Different Frequency Transcutaneous Auricular Vagal Nerve Stimulation on Sensory Perception.
Run by Aalborg University · NCT07325058 · Data updated 2026-11-12
This test will see if brief burst electrical stimulation of the ear's vagus nerve reduces capsaicin-induced skin pain and pressure pain in healthy adults.
Quick facts
| Study type | Interventional |
|---|---|
| Ages | 16 Years to 60 Years |
| Sex | All |
| Enrollment | 36 (estimated) |
| Sponsor | Aalborg University Academic / other |
| Locations | 1 site (Aalborg) |
| Status | Recruiting |
| Started | December 18, 2025 |
| Main results expected | March 2026 |
| Study ends | April 2026 |
| Registry record updated | January 8, 2026 |
| Trial ID | NCT07325058 on ClinicalTrials.gov |
Is this trial a fit for you?
✓Likely a good fit
Healthy adults aged 18–60 who speak English, are not pregnant or breastfeeding, do not regularly use analgesics or recreational drugs, and can tolerate capsaicin and ear electrical stimulation are ideal candidates.
✕Probably not a fit
People with chronic pain conditions, regular use of opioids or other analgesics, pregnancy, neurologic or cardiovascular disorders, or contraindications to electrical stimulation or capsaicin are unlikely to benefit from this protocol.
A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.
What this trial studies
In a randomized crossover design, healthy volunteers attend three ~2.5 hour visits to receive burst transauricular vagus nerve stimulation (taVNS) of the concha cymba, active earlobe electrical stimulation, and a sham (no-current) condition. Capsaicin is applied to induce tonic skin pain, and pressure pain sensitivity is measured as an acute pain outcome. Pain intensity is recorded before, during (twice) and after stimulation; secondary measures include sensory thresholds, resting ECG heart rate, pupillary responses, and conditioned pain modulation. Comparing taVNS against both an active control and sham allows separation of specific neuromodulatory effects from nonspecific or placebo effects.
Why it matters
Potential benefit: If successful, taVNS could provide a non-drug approach to reduce tonic and pressure pain and inform development of new neuromodulation treatments for pain.
How similar studies have gone: Prior experimental human studies report that taVNS can modify pain thresholds and autonomic markers, but clinical benefits for pain treatment are not yet established.
Who can join: the full rules
Show full inclusion / exclusion criteria
Inclusion Criteria: * Healthy * Speak and understand English * 18-60 years old. Exclusion Criteria: * Pregnant and/or breastfeeding * Regular use of cannabis, opioids or other drugs * Current or previous neurologic, musculoskeletal, mental, or other illnesses (e.g., brain or spinal cord injuries, degenerative neurological disorders, major depression, cardiovascular disease, chronic lung disease, etc.) * Current regular (once or more a week) use of analgesic medication or other medication which may affect the trial (including paracetamol and NSAIDs) * Recent history of acute pain particularly in the lower limbs * Abnormally disrupted sleep in 24 hours preceding experiment * Contraindications to electric stimulation application (history of epilepsy, metal implants in head or jaw, etc.) * Lack of ability to cooperate * Contraindications for capsaicin including an intolerance chili consumption and burns or wounds to the application site.
Where it's running
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Center For Neuroplasticity and Pain
Aalborg, Denmark Recruiting
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How to take part
- Review the eligibility criteria above with your treating physician.
- Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
- Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.