The sleep deprivation TV programme Shattered is being investigated by a media watchdog after sparking 11 complaints from viewers.
Psychologists warn against using sleep deprivation for entertainment
Government regulator Ofcom will probe the Channel 4 show, which challenged competitors to stay awake for a week.
The show, won on Saturday by trainee police officer Clare Southern, has been accused of exploiting participants and endangering health.
But Channel 4 insisted contestants' welfare was "of the utmost importance".
"We have gone to great lengths to ensure their health and safety," a spokesman said.
Over the course of the week, Shattered contestants were put through a series of endurance tests - including watching paint dry for one hour - as they competed for £97,000 prize money.
Each day the worst performing contestant was eliminated, with 19-year-old Ms Southern, from Poole, winning a "sleep-off" to beat the other two remaining contestants in Saturday evening's final.
Shattered competitors were allowed occasional catnaps agreed by the producers, but over the course of the week complained of hallucinations, exhaustion and paranoia.
Psychologists have criticised the show and accused programme makers of putting
contestants' health at risk.
Dr Gary Wood, social psychologist at the University of Birmingham, said earlier: "It is humiliation TV and very concerning that what we are doing is putting people's health at risk and causing them psychological harm."