ARLINGTON, Va., Dec. 29 (UPI) -- Manufacturers of synthetic marijuana have altered their recipes to get around U.S. laws that ban the illicit substance, prosecutors said.
The drug, known as spice, is sold openly in stores and on the Internet. A National Institute on Drug Abuse study says spice is the second most frequently used illicit substance among high school seniors, behind marijuana.
The Washington Post said the drug, which some say has gotten stronger, has been linked to seizures, hallucinations, vomiting, anxiety, an accelerated heart rate and death.
Spice manufacturers spray herbs with synthetic cannabinoids and package them as "herbal incense" that is smoked to get high, the newspaper said.
While the chemicals often used in the drug have been banned in about 41 states, recent spice busts have hit roadblocks in a number of states because the spice seized by police didn't contain any of those chemicals.
"I don't know whether we are going to be able stay one step ahead of these chemists," said Arlington County Commonwealth's attorney Richard Trodden.