TAMPA — In the last half-year, the chances a local batch of the club drug Molly actually contained MDMA, widely known as ecstasy, are "zero to one," the managing director of the Florida Poison Information Center said Friday.

The drug typically increases the activity of neurotransmitters in the brain for a euphoric feeling, but "none of the seizures in the last six months to a year have had any MDMA at all," said director Alfred Aleguas.

So what are buyers really getting? Bath salts, Aleguas said.

"These other compounds are easy, cheap to get and maybe in low doses have the same effect," Aleguas said. But the potency could range from high to low, and as younger party people take amounts they think are suitable for Molly, they're spinning into highs they aren't ready for. And some of them land in the hospital.

"We're seeing strokes in young people — teens, 20s, early 30s," Aleguas said, whose poison center operates out of Tampa General Hospital and covers 16 counties in west-central Florida. "That's a population you'd never expect to see an intracerebral bleed."

"Novel psychotic substances" like bath salts and spice are the culprit, authorities say.

"You're basically at the mercy of whatever chemist decided to make it," said Larry McKinnon, with the Hillsborough County Sheriff's Office. "That is usually done in someone's bathroom or someone's garage so there really is a danger."

Aleguas was quick to note these bad batches are sold on the Internet, too, and people who buy online are still at risk.

"They don't know what they're getting. A lot of people who are selling don't know what they're selling," he said. "And they don't really care."

As the prevalence of true MDMA dwindles, a new drug similar to bath salts is surging. Flakka — dubbed "$5 insanity" — is making its rounds in Florida, according to the National Institute on Drug Abuse.

It's the drug Brevard County authorities say a 41-year-old man was on last week when he tried to have sex with a tree, said he was God and attacked an officer.

The cheap drug unleashes a sort of manic delirium and can cause paranoia, hallucinations and violent fits, but McKinnon said the spike seems to be concentrated in South Florida for now.

"We're aware of it and we're looking out for it, but we haven't seen it yet," he said. "It doesn't mean it's not here, we just haven't seen a case of it."

Contact Rachel Crosby at rcrosby@tampabay.com or (813) 226-3400. Follow @rachelacrosby.