More kinds of wearable therapeutic devices are currently being produced to cater to growing demand for at-home medical treatment, but both doctors and industry experts have warned that users should keep an eye out for false advertising claims, reports Global Times.

That went on until this January, when a friend recommended a wearable device designed to help relieve stress, anxiety and insomnia. The first time he tried it, Zhang says, he thought he’d found a cure.

“When I put the device around my head, I gradually felt more relaxed, like I was falling into a state of meditation, and then had a sound sleep, which was amazing,” said Zhang, who now uses the device almost every night, both at home and on business trips.

In recent years, more and more wearable devices that claim to cure illnesses, especially chronic conditions, such as persistent pain, sleeping problems and diabetes, have hit the market, touting themselves as a new, easier alternative to seeing the doctor.

It’s a market with big potential. According to a December article on mddionline.com, an American news portal focused on medical devices and the diagnostic industry, a recent market research report projects that the global health and wearable medical technology market will grow from about $3.5 billion in 2014 to about $17 billion by 2022.