How the vagus nerve affects your health

People “hum into their phones, gargle with theatrical enthusiasm, dunk their faces into bowls of ice water, and poke at their ears”, said Katie Edwards and Dan Baumgardt on The Conversation. They are all trying to “activate” their vagus nerve, the new “favourite body part” of the internet.

Social media is abuzz with the transformational potential of vagus-nerve “training”. Stimulate it and reset it, wellness influencers claim, and you can improve your mental and physical wellbeing.

What is the vagus nerve? 

It’s the longest cranial nerve in your body. Its name derives from the Latin for “wandering” because its two branches rove through your entire body – travelling from the brainstem down into your neck, chest and abdomen, connecting to the heart, lungs, gut and the liver. It constantly relays information from your brain to your organs and back again, and is often described as an internal communication superhighway or our body’s intranet.

How important is it? 

As “signal updater” between brain and body, the vagus nerve is a part of the autonomic nervous system that regulates processes you don’t consciously control, such as heart rate, breathing and digestion. Within that system, it has a key role in the parasympathetic response – sometimes known as “rest and digest” – slowing heart rate and decreasing blood pressure. Put simply, when you feel calm, safe and relaxed, your vagus nerve is helping to make that happen.

The theory is that your body can sometimes get “stuck” or spend too long in the opposite sympathetic response – known as “fight or flight” – and stimulating the vagus nerve can prompt a return to calm.

Can stimulating it make you healthier?

Implanted devices that directly stimulate the vagus nerve have long been used to treat neurological conditions like epilepsy and treatment-resistant depression. More recently, trials of transcutaneous devices, often placed around the neck or in the outer ear, have shown promising results in treating conditions including diabetes, Crohn’s disease, fibromyalgia and irritable bowel syndrome.

This kind of non-invasive vagus-nerve stimulation (VNS) first entered the “mainstream consciousness” as a “biohacking tool” in the 2025 Netflix documentary “Don’t Die”, said Vogue. The film followed US tech entrepreneur Bryan Johnson’s “longevity journey” and the “anti-ageing” crusader is shown wearing a VNS gadget that, he said, helps him manage stress and get to sleep.

From then on, the vagus nerve got “the trendy treatment”, said The Independent. Wearable devices swiftly appeared on the market that were said to enable VNS by sending a “specific level” of electrical current through the nerve that will “wake up” or “reset the system”, much like “rebooting a computer”.

I am cautious about claims that the vagus nerve can be “switched on like a light”, Arshad Majid, a professor of cerebrovascular neurology at the University of Sheffield, told Edwards and Baumgardt on The Conversation. There’s “not an on-off button” that these devices, or other DIY methods, like humming or gargling, can trigger. And, in some cases, trying to stimulate the nerve can “trigger headaches and even depression”.

That said, we are running various clinical trials on non-invasive VNS devices, and the “next few years of research” could “reshape” how we treat a range of conditions. But you should “maybe hold off on aggressively poking your ear” for now.