A coroner’s report has revealed that Michael Jackson may have been taking the banned stimulant ephedrine at the time of his death. The Los Angeles County coroner’s report revealed that the singer also had the anesthetic propofol and the sedative lorazepam (Ativan) in his system, both of which contributed to his death.

Some experts who have learned about the report’s findings were surprised at the mention of ephedrine, which was banned by the Food and Drug Administration in 2004. Although ephedrine can be used for resuscitation, the doctors say that it is unlikely that emergency personnel called to Jackson’s home would have used the stimulant for that purpose.

Ephedrine is the active ingredient in the herb ephedra, which was once commonly marketed for weigh loss before the FDA ban went into effect. Ephedra, also known as ma huang, was also sometimes combined with other herbal products and marketed as “herbal Fen Phen” after the agency ordered a recall of the popular diet drug combination Fen Phen in 1997.

The FDA warned about the risk of side effects with herbal Fen Phen shortly after the Fen Phen recall was issued. In 2004, following the deaths of two high profile athletes and at least 100 other ephedra users, the FDA banned herbal Fen Phen and other products containing ephedra or ma huang.