News mentioned Propofol. It is widely used for short term anesthesia in medical procedures like colonoscopies and impacted tooth removal. It is given intravenously and you are out like a light and you wake up easily after the procedure when the administration is stopped. You feel nothing and remember nothing about what was just done . It was thought that Michael had used other drugs earlier in the day in the benzodiazepine class which would have depressed his respiratory and circulatory systems before succumbing to the Propofol dosing , according to news reports after his death.