Ear-Clip Nerve Stimulation Did Not Lower Blood Pressure Overall, Small Trial Finds

A handheld device that sends mild electrical pulses to the ear did not lower blood pressure more than a sham device across a whole group of people with hard-to-control hypertension, according to a new randomised trial.

The study, called SCRATCH-HTN, was published in Hypertension in 2026. It was a double-blind, sham-controlled, phase 2a trial. That means neither the participants nor the researchers knew who had the real device, and an early-stage trial like this mainly checks safety and gives a first look at whether a treatment works. It enrolled 63 adults with uncontrolled hypertension who were already taking one or more blood pressure medicines.

Roughly 40% of people with hypertension do not reach recommended blood pressure targets despite medication, the authors write. Device-based options exist, but they are often expensive or invasive. The team tested a noninvasive approach called transcutaneous autonomic neuromodulation, or tAN. It uses a device to stimulate sensory fibres of the vagus nerve through the skin. The vagus nerve is part of the autonomic nervous system, which helps regulate heart rate and blood pressure without conscious control.

Participants had an average age of 47.2 years, and 71.4% were male. Their average daytime blood pressure was 150/95 mm Hg. They were randomly assigned 2:1 to active tAN or sham treatment. They gave themselves 30 minutes of treatment daily for 14 days, then 10 weekly sessions.

The main safety and acceptability goals were met. The authors conclude that tAN was safe and well tolerated.

The main efficacy question was whether daytime systolic blood pressure, the top number, changed from the start of the study to three months. It did not differ significantly between groups. The gap between active and sham was 2.35 mm Hg, with a 95% confidence interval from −4.37 to 9.07 (P=0.49). At one month the difference was −1.01 mm Hg (−6.87 to 4.85; P=0.73). Those intervals are wide and include both no effect and a modest effect in either direction. No significant differences appeared for other secondary measures, including heart rate and quality of life.

There was one signal in a pre-specified analysis. The researchers found a significant interaction between treatment and starting systolic pressure (P interaction 0.003). People whose baseline systolic pressure was above 160 mm Hg showed a greater response to active tAN. The abstract does not give the size of that response or the number of people in that group. With only 63 participants, subgroup findings can be chance results and need confirmation. The authors' own conclusion is measured. No significant blood pressure-lowering effect was demonstrated. A benefit in subgroups, or a modest effect in a larger group, cannot be excluded and warrants evaluation.

The press coverage went further in tone. ScienceDaily, relaying a Queen Mary University of London release, described the device as showing "early promise". It quoted chief investigator Dr. Ajay Gupta as saying the technology "could ultimately provide a cheap, scalable solution for millions" and that those with more severe hypertension showed "a clear blood pressure reduction" on the active device compared with sham. Those are the investigators' views. The published abstract supports safety, and it supports a hypothesis about higher-pressure patients. It does not show that the device lowers blood pressure.

Larger trials designed to test whether people with very high starting blood pressure truly respond to tAN. Anyone considering starting, changing or stopping any blood pressure treatment, including a device, should talk to their own clinician first.

Sources: Hypertension (Dallas, Tex. : 1979) (2026), ScienceDaily (Queen Mary University of London;