Demi Lovato: US singer rushed to hospital after suspected heroin overdose

American pop star and actress Demi Lovato has been rushed to hospital in Los Angeles after a reported heroin overdose.

The 25-year-old former judge on American X Factor was said to have been found unconscious at her Hollywood Hills home.

Lovato, who has been candid about her struggles with cocaine abuse and self harm, was treated with the emergency drug Narcan, TMZ reported.

A spokesman for Lovato said: "Demi is awake and with her family who want to express thanks to everyone for the love, prayers and support.  

"Some of the information being reported is incorrect and they respectfully ask for privacy and not speculation as her health and recovery is the most important thing right now."

News crews gathered outside Lovato's home in the Hollywood Hills, where vehicles were seen entering and leaving on Tuesday afternoon.

#PrayForDemi: Celebrities 'send love' to star

The hashtag #PrayForDemi trended on Twitter and several celebrities posted supportive words, including Lady Gaga, Ellen DeGeneres, Missy Elliott, Ariana Grande, Brad Paisley, Kesha, Bebe Rexha, Meghan Trainor, Maren Morris, Kehlani and British electronic group Clean Bandit, whose current single "Solo" features Lovato.

Relapse after 'six years of sobriety'

The singer, a child star who released her first album in 2008, has been open about her mental health problems.

From 2010, she discussed her struggle with bipolar disorder, addiction, an eating disorder, and self-harm.

In 2013 she released the book Staying Strong: 365 Days a Year, and in 2017 she produced a YouTube documentary about her life and career, titled Demi Lovato: Simply Complicated.

Lovato - Credit: Getty
Demi Lovato sings the national anthem before a boxing match between Floyd Mayweather Jr and Conor McGregor in Las Vegas, in August 2017 Credit: Getty

Lovato was believed to have been sober and free from drugs for six years, until her new single Sober revealed she had relapsed.

Yet on Monday night, according to TMZ, she was seen celebrating a friend's birthday in West Hollywood, and posted photos on her private Instagram of herself and others in the group, seemingly happy.