The drugs behind Demi Lovato's OD have been revealed


Fentanyl has quickly risen in the ranks of problem drugs in this country.  It killed PRINCE, and now we're finding out it may have almost killed DEMI LOVATO.

TMZ says Demi's overdose was caused by Oxycodone laced with Fentanyl.  She supposedly called her dealer at around 4:00 A.M., and they freebased the stuff on tin foil. 

Then he TOOK OFF when he saw her lying in bed, breathing heavily.  It's not clear exactly what time she took the stuff, but it wasn't until 11:30 when someone on her staff found her.  At that point, she had to be revived with Narcan. 

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