Whether it’s called K2 incense, spice or “fake weed,” synthetic marijuana has been spotted in smoke shops across the country during the past year, and the drug’s popularity continues to grow.

According to a September report by the U.S. Poison Control Centers, use of the drug resulted in 1,800 calls from emergency rooms nationwide in the past year looking for information on how to treat the effects from use. It is made from a leafy, herbal plant with a chemical liquid sprayed onto it. When consumed, the product has a result similar to that produced by marijuana.

“It is enough [of a concern] it is on the Poison Center’s radar screen,” said Jessica Wherman, communications manager of the American Association of Poison Control Centers. “We are concerned about the symptoms being considered as side effects.”

Wherman said side effects reported include hallucinations, fast–racing heart beats, nausea and vomiting.

Michael Wahl, medical director of the Illinois Poison Center, said one of the side effects that is different from marijuana use is seizures, and it could be potentially more dangerous.

“It certainly appears to be [more dangerous],” Wahl said. “People don’t end up tied down in the emergency room or have seizures from smoking marijuana.”

Wahl said there are no reported deaths, but no proper testing for the drug exists at the moment.

“So if someone did die of it, we wouldn’t know,” Wahl said.

The product can be found in head shops, smoke shops and bait and tackle stores.

Barbara Carreno, spokeswoman for the Drug Enforcement Administration, said it is easily found online, with labels that read “not for human consumption.” But she doesn’t believe the warning is followed.

“There are other ways to tell whether something is intended for human consumption,” Carreno said. “For example, when you see something labeled incense, sold for $100 by the gram and the [website] says it will ship it discreetly, that just doesn’t apply to incense. When was the last time you bought incense and had to have it shipped discreetly?”

Carreno said K2’s use has been around for a few years in Europe, but she began hearing about it last December. Originally, the drug was used in research projects to study THC, the active ingredient in marijuana, and its effects.

“The intent wasn’t people would ingest and use it,” said Will Taylor, public information officer for the Chicago Division of the DEA. “It was to better understand THC effects on the body.”

Taylor explained the effects of the drug don’t come from the plant but from the chemical sprayed on the plant. When the drug is used, it is unknown what or how much of the synthetic drug is being consumed.

“It’s synthetically produced for these different effects that have [similar] effects to marijuana,” Taylor said. “[Users] know why they are using it; what they don’t know is what they are getting themselves into as far as side effects.”

Wahl said there are different types of THC receptors in the brain and because this is not the same THC found in marijuana, it will bind to receptors differently. There can be dozens of different variations of synthetic marijuana.

The long-term effects of synthetic marijuana are still unknown, Carreno said. The DEA is currently evaluating the different chemicals in the drug. Currently, HU-210 is a controlled synthetic marijuana.

The compound JWH-18 will be illigal starting Jan. 1, 2011, according to JWH-Info.

“We are evaluating some of the other chemicals to see whether they should be controlled,” Carreno said. “We have had this on our radar for [more than] a year.”

Wahl explained forms of the drug are still legal because of the molecular formations.

“The way things are done in this country are based on structure,” he said. “THC, the active ingredient in marijuana, is illegal, but if I were to alter it so there is a separate carbon molecule or nitrogen molecule, it is no longer the same molecule [as THC] and is now legal until someone says that structure is illegal.

Since its creation, word has spread on how to make the drug. Instructions and places to order from can be found online.

“Just because the product is legal, doesn’t mean it’s safe,” Taylor said. “There are a lot of household products out there people would never ingest or use.”

Carreno said a main reason a user would choose this drug over marijuana is because it is legal and does not show up in drug tests which look for specific things.

Wahl said if a chemical variation becomes illegal, all it would take is one molecule change to make it legal again.

“If there is somebody else [who] can invent a chemical compound structurally similar but slightly different and is not on the banned list, it can be potentially marketed and will be legal,” Wahl said.