The substance, known as "spice" or "K2," is a cannabinoid, a class of drug that includes THC, the active ingredient in marijuana.
First synthesized in an academic chemistry lab in South Carolina for pharmaceutical research, it moved on to be a plant-growing aid in Asia and then a substitute for marijuana in Europe before its recent emergence in the United States, where it skirts the laws placed on its herbal cousin.
"The stuff that's been put into the incense was originally made in our lab 15 years ago," said John W. Huffman, a professor of organic chemistry at Clemson University.
Huffman said his research, funded by the National Institute on Drug Abuse, was focused on making a drug to target endocannabinoid receptors in the body. While the better known receptor is the one in the central nervous system that gives a high, another in the immune system is tied up with inflammatory pain.
The active ingredient in spice is known to scientists as JWH-018, since it was the 18th such compound the lab made.
JWH-018 was likely chosen, Huffman said, because it is the easiest of its type to be synthesized outside a lab, requiring just two steps using commercial products.
But getting a pure version is another story.
"People are getting reactions to [spice] that are not typical of cannabinoids," Huffman said. "You're dealing with a very potent cannabinoid and also you don't know what is in this herbal product that you buy for 40 bucks a bag."
And a number of people have paid the price, being hospitalized after using the drug for ailments ranging from stomach problems to seizures.
"These products weren't designed for human consumption," said Dr. Alvin C. Bronstein, medical director of Rocky Mountain Poison Center and director of surveillance for the American Association of Poison Control Centers.
He said the drug recently came on his organization's radar and they have begun tracking spice's use, although it is too soon to know for certain the trend in spice's use.
"At this point, we don't know how much of a problem this is going to be," said Bronstein.
Judging by patients who contact the poison control centers, Bronstein said that people are probably using spice for the same reason they would smoke marijuana.
"It's like a designer drug where you've got a drug similar to marijuana, but it's not marijuana, although it acts similarly in the system," he said.
Bronstein said parents need to play their part in warning their kids.
"If they see the kids with these products, with this incense ... they need to have a talk with their children about this," he said.
One problem is that no one knows if people are getting sick because the drug is not purified enough or because of a problem inherent in spice.
Unlike marijuana, Huffman said, not much is known about spice's effects.
"You can't tell until somebody tries controlled trials with something," he said.
Huffman said he first read about his drug leaving the lab a couple of years ago, when he found, through Google, it was being sold in China and Korea to stimulate plant growth.