CBS News Correspondent Bobbi Harley says that's because there's a dangerous new knockoff that looks like Ecstasy, but is far more dangerous. Not knowing the difference can be costly.
Those who have been exposed to Paramethoxyamphetamine, called PMA, say it's not hard to understand why the drug is known in the clubs as "Death."
The U.S. Drug Enforcement Administration is now using undercover surveillance videotape to try to track PMA.
So far, the killer club drug has been more often identified in the morgue than on the dance floor.
"I wouldn't say it's an easy drug to detect," says Toxicology Supervisor George Hime of the Miami-Dade Medical Examiner's office in Florida.
In fact, it's so hard to detect that investigators thought it was overdoses of Ecstasy that killed three Chicago area teenagers last May and then six more young people in central Florida since Julythat is, until toxicology tests found something much more lethal: PMA.
Unlike the stimulant Ecstasy, which is a euphoria-producing drug, PMA is more potent and has a deadly side effectraising the body temperature so high, the central nervous system literally burns itself out.
"When the user thinks they're using Ecstasy when in reality they're using PMA or Ecstasy mixed with PMA, they consume more of the drug and eventually experience its toxic effects," says Hime.
On the streets of south Florida, police are only beginning to realize what they're dealing with. A recent seizure of what they thought was Ecstasy turned out to be pills they couldn't identify. It took the DEA's national drug laboratory to determine the pills were PMA.
Vincent Mazzilli is the DEA's special agent in charge in south Florida. "An experienced drug agent or undercover police officer will not know one tablet from the other."
Neither do the dealers or the buyers, who keep using Ecstasy, or what they think is Ecstasy, at near epidemic levels.
Nidia Atehortua, a former Ecstasy user, is not expecting a quick crackdown on PMA. "It's going to have to take a lot of people, a lot young people to die for them to actually realize that this drug is really killing."
And that, the DEA admits, may be the only way to track this new drug, because even though they know it's out there they don't know exactly where.