It's a new drug. And it's a killer.
Known on the street as "flakka," the synthetic concoction is hitting hard in Florida, Tennessee, Kentucky, Ohio and other parts of the country. It's causing a rash of emergency room visits and overdose deaths.
In one highly publicized Florida case, a man reportedly high on flakka gnawed on and disfigured another man's face before he was shot to death by police. Another user tried to break down the door of a police station in Fort Lauderdale, and a few weeks later, a man impaled himself while trying to climb a fence around the same station.
"This is the worst drug I have ever seen in my 18 years of law enforcement, across the board," said Johnny Bivens, sheriff of Lewis County, Ky. "Nothing compares to this."
Also known as alpha-PVP, it has a similar chemical makeup to other drugs commonly known as "bath salts," according to the National Institute on Drug Abuse.
It typically comes in a white or pink crystalline form and is foul-smelling. It can be eaten, snorted, injected, or vaporized in an electronic cigarette device, according to the national institute, which has included flakka on a list of emerging trends.
It is particularly potent when vaporized, sending the drug into the bloodstream quickly, and making the user particularly susceptible to overdose.
"Alpha-PVP can cause a condition called excited delirium that involves hyperstimulation, paranoia and hallucinations that can lead to violent aggression and self-injury," the institute warns. "The drug has been linked to deaths by suicide as well as heart attack. It can also dangerously raise body temperature and lead to kidney damage or kidney failure."
Authorities say flakka is easily accessible. It can be purchased online from China and in some parts of the United States has replaced crack cocaine.
Officials in Broward County say the drug has contributed to at least 29 deaths over the last year.
"The dangerous thing about synthetic drugs is that the chemicals used to make them are always changing," said Sgt. Chris Cesena of the Kansas City police drug enforcement unit. "The user doesn't realize what they're taking. These are harsh chemicals."
Capt. Dan Cummings of the Jackson County Drug Task Force said synthetic drugs can vary widely in their potency from batch to batch.
In a recent investigation involving the sale of K2, commonly known as synthetic marijuana, Cummings said, confiscated samples tested in a laboratory ranged from 3 to 4 percent pure to as high as 80 to 90 percent.
Someone used to the weaker form is at a higher risk of overdose if they unknowingly ingest a purer form, he said.
Bivens said his office in Kentucky became aware of the drug around Thanksgiving when reports of people acting strangely, sweating profusely and displaying intense paranoia started coming in.
"They always constantly think that someone is after them," he said. "One of the main things we have seen was people experiencing rapid weight loss, about 40 pounds a month. People don't eat. They are up for 10 to 12 days at a time. Their body becomes covered in abscesses."
Users report that the drug is highly addictive, he said.
And it is highly profitable for the people selling it. Dealers were able to obtain the drug online and were selling it for $250 a gram, he said.
The problem peaked in the spring when Bivens said they were responding to two or three flakka-related calls a day.
And more often than not, when his deputies encountered users, they were involved in intense physical encounters to control them.
"Foot chases were going up," he said. "The use of force was going up because when you encounter these individuals they think you are trying to kill them and they would react and we would have to upgrade the use of force."
Flakka started appearing in the United States in a handful of cases in late 2012, said Rusty Payne, a spokesman for the Drug Enforcement Administration.
By last year, a "tremendous" number of cases were being reported, he said.
In the last seven or eight years, officials have identified 400 varieties of synthetic drugs.
"Alpha-PVP or flakka is just another one that has emerged unfortunately and it is causing a lot of problems in a lot of places," Payne said.
The area hit hardest by the drug is Broward County. It first surfaced there last year, said Lt. Ozzy Tianga of the Broward County Sheriff's Office.
At first, because users displayed many of the same symptoms and behaviors seen with cocaine or other synthetic drugs, officials did not realize they were seeing something new, he said.
The level of "excited delirium" experienced by flakka users tended to be much worse, and laboratory testing confirmed the presence of something new, according to Tianga.
"They were acting psychotic, very similar to acting as if they were mentally ill," he said.
Based on calls from other parts of the country, Tianga said he expects the drug to continue spreading.
"I have received calls from Kentucky, all of the northeast quadrant of the United States, from Texas all the way up to California," he said.
Payne of the DEA said that despite the claims of those who sell it online, it is illegal in the United States.
"A lot of people like to think legal means safe; therefore I can do this and be safe," Payne said. "There have been a lot of funerals unfortunately that have operated under that assumption."