NEW YORK – Running along either side of your neck is a pair of marvellous fibres that scientists call the vagus nerve. Sometimes called a “pacemaker for the brain”, this nerve connects the brain to most major organ systems in your body.

For centuries, the nerve has chugged along in relative obscurity, but recently, it has reached an almost mythical status among podcast hosts, social media influencers and others in the wellness ecosystem.

Cannot sleep? Hit it with electricity. Stressed out? Keep zapping. Brain fog, inflammation, digestive issues? You guessed it.

“There are billions of web impressions and social media posts on the vagus nerve,” said Kevin Tracey, a neurosurgeon and president of the Feinstein Institutes for Medical Research at Northwell Health. “A lot of it is being driven by influencers who are saying, ‘Just do this to simulate your vagus nerve, and all the problems in your life will be solved.’”

Celebrities such as actress-host Kelly Ripa and health influencers including Andrew Huberman have extolled the benefits of vagal stimulation. Some of the advice is innocuous enough, such as humming or deep breathing techniques.

But many influencers have gone further, endorsing devices worn around the neck or ears that transmit electrical pulses. Some forecasters say vagal stimulation will be a billion-dollar industry by 2030.

Some vagus nerve stimulators are real medical devices that have been approved by the federal government for a handful of conditions. But many of the gadgets you might see online do not work, Tracey said, and simply trade on the credibility of medical-grade stimulators – available only through surgery or by prescription.

In other words, vagus nerve stimulation is grounded by enough science to sound serious and surrounded by enough mystery to sound limitless, he added.

The vagus nerve is one of the body’s major information highways, with 200,000 fibres running from the brain to the heart, lungs, stomach and more, before ending at the colon.