The demand for legal synthetic marijuana known as K2 is on the rise in the U.S. prompting Missouri to ban the use of the drug.

Poison centers nationwide received 500 calls about the designer drug this year. There were only 12 calls about k2 last year.

The Georgia Poison Center reported receiving more than 50 calls about K2 since May.

Dr. Gaylor Lopez, director of the center, warned that K2 is incredibly dangerous because it K2 can be up to 15 times more powerful than marijuana. Symptoms are tremors and seizure.

K2 is available online and can be sourced through magazines.

They'll market it as incense, or bath salts, CBS News quoted Drug Enforcement Administration (DEA) Special Agent Gary Boggs as saying.

The DEA is testing the drug to determine if it should be declared a controlled substance, according to Boggs.
Drug tests cannot detect it.

K2 is legal in 44 states but is banned in Alabama, Georgia, Kansas, Kentucky, Louisiana and Missouri.
Illinois, Michigan, New Jersey and New York plan to ban the drug.