Demi Lovato has been hospitalised after overdosing on heroin. TMZ reports that the singer was transported from her Hollywood Hills home to an undisclosed medical facility shortly before noon on Tuesday.

A law enforcement source confirmed that the overdose occurred at Lovato's home and that she was found unconscious before being given Narcan and transported to the hospital where she is stable.

Lovato, 25, has been incredibly open about her struggles with alcohol and drugs, and earlier this year debuted her single 'Sober' in which she detailed her battles and path to recovery.

She performed that song on Sunday night at the California Mid-State Fair, her last appearance before being hospitalized on Tuesday.

During the performance, Lovato struggled to remember the words to her song.