UPDATE from TMZ:
1:28 PM PT -- Law enforcement sources tell us Demi was treated with Narcan -- an emergency treatment for narcotic overdoses -- at her home. We've confirmed the OD occurred at her house in the Hollywood Hills.
Update from TMZ
Demi Lovato was reportedly rushed to an L.A. hospital after suffering an alleged heroin overdose. TMZ says they have spoken to law enforcement and got the report.
Demi was transported from a home in the Hollywood Hills just before noon today, and is currently being treated. Her condition is not known.