Adult pacifiers which claim to relieve anxiety and improve sleep have become a trending product in China, sparking concerns from doctors and internet users, El.kz cites scmp.com.

Some online shops claim they sell more than 2,000 such items a month.

They are described as being bigger than the baby version and sell for between 10 and 500 yuan (US$1.4 and US$70), the news outlet The Cover reported.