FOX UNDERCOVER – Banned by the DEA and dubbed a dangerous substitute for the real thing, synthetic marijuana was easily found on Boston store shelves by a FOX Undercover hidden camera investigation.

Inside an Allston head shop, the clerk retrieved a packet under the counter for a FOX Undercover photographer and intern. Twenty dollars later, a packet of Mr. Nice Guy was in our hands.

“I’d really rather have nothing to do with this,” the owner of the store told FOX Undercover reporter Mike Beaudet.

“The DEA says it’s illegal, dangerous?” Beaudet asked.

“I have no comment. Can’t help you,” the man replied.

It was the same story in two other stores where we found synthetic marijuana for sale. Marketed as incense and going by names like Spice and K2, the packets contain innocuous plant material typically sprayed with man-made chemicals that are supposed to mimic marijuana’s high.

“Clearly these aren’t really incense?” Beaudet asked.

“Oh no, definitely not,” replied Chip Cody, a chemist with JEOL USA in Peabody. JEOL USA is a company that sells sensitive lab equipment that can detect every molecule inside a substance.

Cody tested the samples we bought. He found the first one loaded with a substance known as AM-2201, which was developed at Northeastern University for research purposes. Its molecular structure resembles that of powerful hallucinogens like psilocybin and LSD, Cody said.

The three samples had small differences in their molecular structure, a common tactic of synthetic pot chemists trying to evade the law.

“This is really quite wild hanging a fluorine on the side,” Cody said, looking at the structure of one of our samples. “That’s some kind of thing they’re doing just to try and trick the chemists.”

They’re trying to trick the chemists because the drugs can be so dangerous.

Another chemist who has studied synthetic marijuana for years says they should all be illegal.

“People have shown up in hospitals, the year-to-year increases in poison control data is through the roof. People have died,” said Jason Shepard, a professor at the University at Albany-SUNY.

Shepard’s research has shown that different samples of the same brand of the man-made marijuana can have wide variations in the amount of drugs in any one packet, as much as 10 times the amount from one sample to another, so smokers have no idea how much they’re taking with each hit.

It’s not just scientists who are concerned.

Far from the mellow pot smoker, synthetic marijuana users have turned violent and suffered serious side effects, according to Kevin Lane, Assistant Special Agent in Charge of the U.S. Drug Enforcement Administration’s New England office.

“Do people selling this stuff know what they’re selling?” Beaudet asked him.

“They absolutely know and oftentimes when we have undercover activity into it or even speaking with some of the people that are distributing it, they’ll indicate that they know they need to keep it out of view,” Lane replied.

They need to keep it out of view because the DEA has banned most kinds of synthetic marijuana. Even if a manufacturer cooks up a batch with a different molecule, the DEA says they can prosecute if the structure and effect are essentially the same.

“The synthetic pot that we bought, is it against the law to be selling that?” Beaudet asked.

“Yes, absolutely,” Lane replied.

Another reason authorities don’t like the synthetic weed is that it is not detected by typical drug tests.

FOX Undercover tried to contact each of the manufacturers of the products we bought and either got no response or could not be reached for comment.

One store owner we bought from earlier this year stopped selling it, according to Mitch Rosenfield, owner of Hempest on Newbury Street.

“I didn’t really agree with the whole philosophy of it. It just didn’t seem like a nice product to be selling, and reading more and more stories about it just didn’t seem like a smart thing to do,” Rosenfield said.