NCT02821741

Effects of External Ear Stimulation on Pain Perception and Mood

Recruiting now NA Last updated 14 April 2026

What this trial tests

NA trial testing The Twin Stim Plus, 3rd Edition in Pain in Healthy Participants in 76 participants. Currently enrolling.

Timeline

18 October 2016

Primary endpoint
30 March 2027

30 March 2027

Quick facts

Lead sponsor	National Center for Complementary and Integrative Health (NCCIH)
Phase	NA
Status	Recruiting now
Study type	INTERVENTIONAL
Allocation	randomized
Design	crossover
Masking	triple
Primary purpose	basic science
Enrollment	76
Start date	18 October 2016
Primary completion	30 March 2027
Estimated completion	30 March 2027
Sites	1 location across United States

Drugs / interventions tested

• The Twin Stim Plus, 3rd Edition
• Medoc Pathway System

Conditions studied

• Pain in Healthy Participants — all drugs for Pain in Healthy Participants →

Sponsor

National Center for Complementary and Integrative Health (NCCIH) — full company profile →

Who can join

Adults 18 to 50, any sex, with Pain in Healthy Participants. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

Background:

The vagus nerve runs from the brain to many organs. Stimulating it can affect the experience of pain. The nerve can be stimulated on the surface of the left ear. Researchers want to study how this stimulation affects the perception of pain. They also want to study how mood affects the experience of pain.

Objective:

To study the effects of mood and vagus nerve stimulation on the experience of pain.

Eligibility:

Healthy people ages 18 and older who are fluent in English

Design:

Participants will be pre-screened with a 15-minute phone call.

Participants will have three 2-hour visits.

At the screening visit, participants will be screened with:

Medical and psychiatric history

Physical and psychological exams

Questionnaires about physical and psychiatric health and mood

Urine tests

A heat probe on the forearm. The temperature will be increased until it is painful

but tolerable.

Participants will have 2 testing sessions within 7 days. Before the testing, they cannot do the following:

Eat, use nicotine, or exercise for at least 2 hours

Drink alcohol for 24 hours

Take certain medicines for 3 days

Testing includes:

Urine drug screening

Left ear stimulation: In one session, the vagus nerve will be stimulated. In the other, an area

of the ear away from the vagus nerve will be stimulated. This will be done with mild electric

shocks that cause a tingling, pricking, or itchy feeling.

Heat applied to the forearm until it is painful but tolerable

Completing several forms on a computer or on paper about how they are feeling

Monitors on the chest and a finger clip to monitor heart, breathing, and blood pressure

Publications & conference data

No peer-reviewed publications indexed yet for this trial.