Synthetic marijuana, or "fake" pot, is nothing like the real thing. It's legal, and easily accessible to kids.

It's also a bigger threat to kids' health.

"Marijuana has been used for medicinal and recreational purposes for hundreds of years," said Dr. Jeff Lapoint, a senior toxicology fellow at New York University, Bellevue Hospital. "It's been abused, but no one really gets sick."

"Kids need to know that this substance is more dangerous," Lapoint said.

Popularly called K2, or Spice, synthetic marijuana is a chemical similar to cannabis that gives a marijuana-like high.

But there have been an increasing number of cases of people experiencing seizures, heart palpitations, fever, dehydration and some psychotic episodes after using the drug.

A more potent version of marijuana

Since 2004, K2 has been sold and packaged as incense or potpourri, in the guise of a mixture of herbs and spices. It sells for about $30 to $40 per 3-gram bag, comparable to the cost of marijuana.

Drugmakers can make hundreds of versions of the chemical compound, and it's easy to manufacture.

Although the Drug Enforcement Administration has taken steps to ban five chemicals sometimes found in K2, versions of the compound have multiplied, and increased in use over the past few years.

According to the National Institute on Drug Abuse, 11 percent of nearly 15,000 high school seniors surveyed reported using K2 in 2011.

That year, poison control centers reported handling nearly 7,000 calls about K2, nearly double the calls received in 2010.

One recent study suggests that K2 could increase the risk of psychosis, even among people with no history of a psychiatric disorder.

"K2 is a more potent substance than natural marijuana by its actions on the brain," said Dr. Ashwin Reddy, an author of that study and a psychiatrist at the Boston University School of Medicine. "It can cause an increased risk of paranoia, hearing voices, disorganized behavior and panic symptoms."

"Depending on the person, psychotic symptoms can last a few days to a few months," Reddy said.

Not intended for human use

K2 is sometimes reported as having originated in Europe, but was actually developed by John W. Huffman, a chemist at Clemson University in South Carolina.

Initially created as a medical treatment, the substance works on the brain the sameway as marijuana's active ingredient, tetrahydrocannabinol, or THC.

THC is the substance in marijuana that produces the "high" feeling of intoxication that pot smokers crave.

"This drug was never intended for people to use, just for use in a lab," Lapoint said.

But also disturbing is the unregulated amount of chemicals added in each package.

"You don't know how much of which chemical they put in each package so you don't know what you're getting and how your body will handle it," he said.

Pass it on: Synthetic pot is a more potent — and dangerous — form of marijuana.

This story was provided by MyHealthNewsDaily, a sister site to LiveScience. Follow MyHealthNewsDaily on Twitter @MyHealth_MHND. Find us on Facebook.