"The lure and the attractiveness of it was that it was legal and couldn't be tested," said Gaylord Lopez, the director of the Georgia Poison Control Center.
Respiratory failure, hallucinations, anxiety attacks, rapid heartbeat, vomiting, seizures, unconsciousness and death can be among the side effects.
Teenagers and adults yearning for a legal high have sought out the drug known as Spice, K2 and Blaze.
"We had this one guy who worked for a major airline (in Atlanta)," Lopez said. "He and his wife were fooling around with it, and she started noticing that her husband was having seizure activity."
Synthetic marijuana is legal in 34 states. Georgia is not one of them.
After poison centers in the state began getting calls at the end of 2009, Georgia quickly moved to ban the product last summer.
HU-211, one of the five chemicals used to mimic the effects of marijuana, was classified as a schedule-1 drug, making it a felony to possess any amount of it. Drug tests were developed to recognize the chemicals.
The Drug Enforcement Administration in Georgia launched emergency action to outlaw four more chemicals.
The chemical compounds were created in a Clemson University lab for research purposes in the mid-1990s. The products became hot items overseas before the craze hit the United States.
"You don't know what you're getting when you buy these products," said Chuvalo Truesdell, a DEA spokesman in Atlanta, in an e-mail. "There is no list of ingredients. To know what you're getting you have to test it in a lab.
"Many retailers have reported they don't know what chemicals are in the products they sell so they don't know if they're breaking the law or not."
Lopez estimated the chemical compounds are four to 10 times more active than THC, which is found in pot. He said some argue that it's even higher.
"An investigator went out to all the shops that sell tobacco-related products," Richmond County sheriff's Lt. Robert Partain said. "At the time, they had all voluntarily pulled all of the Spice and returned it to the manufacturer."
So far, Richmond County hasn't made an arrest for possession of Spice. Columbia County has. The case is pending while the drug is being tested.
"We can't be certain that's what it is, but that's what we feel like it was," Columbia County sheriff's Lt. Shariff Chochol said of the substance discovered in November.
He said he believes that officers aren't seeing as much of the substance because of the legal consequences and because it doesn't give the high that people are expecting.
"If it is being used, we're not hearing about it," Columbia County sheriff's Staff Sgt. Trip Penn said. "We're not getting complaints from parents about it -- or anybody else, for that matter."