That smile may not be illegal - yet.

Whether you call it "spice" or designer dope or by one of its many brand names - Bombay Blue, Dragon or Black Mamba among them - the effect is billed to be about the same. When you smoke it, you'll catch a buzz similar to that produced by marijuana.

And drug testing won't necessarily show the user has been high.

But unlike buds and leaves from the cannabis plant, spice can be scored in Utah's smoke shops, head shops and other places for as little as $10 a gram, although prices vary greatly.

"We sell a lot of it," said one smoke shop clerk who identified herself only as Tawny. "It's totally legal. You just have to be 19 to buy it."

But at some stores, where spice is sold as incense, there is no regulation at all, said Salt Lake City police Lt. Mike Ross.

The concern of law enforcement, he said, is that the product is likely to fall into the hands of teenagers who are looking to experiment with getting high.

And according to one teenager, the stuff works, if not quite as well as the real thing. The easy availability makes it a choice for teens who like marijuana but can't always get it, she said.

The 18-year-old, who asked to be identified as Sam, said she smoked spice after her boyfriend bought some at a tobacco shop.

"I tried it and I enjoyed it," Sam recalled. "But I prefer weed [marijuana], because it's more relaxing... The high on spice is more of a stimulant."

Another teen named Caleb said he hasn't smoked it and probably won't, based on the reaction of friends who did toke some up.

"They said that they hated it," he said. "The exact words from one were, 'It felt like flaming spiders were crawling up and down my throat. It was horrible.' "

Spice might be described as a so-called designer drug -- one that is produced in a laboratory to mimic effects of a controlled substance. More technically, it's an analog of tetrahydrocannabinol -- or THC -- the main psychoactive molecule in marijuana.

The drug is packaged in different ways. Sometimes it is mixed with leaves from the shrub damiana, which is said to have medicinal properties. More broadly, spice is any kind of herb that's been spiked with a THC analog, according to Glen Hanson, University of Utah professor of pharmacology and toxicology.

Spice remains legal in most states, although the military now forbids its use, he said.

The drug is relatively new to Utah. But law enforcement officials this year urged legislators to classify it as a controlled substance in order to stop over-the-counter sales.

But lawmakers didn't pass any such legislation during the regular session that ended March 11. They did, however, place it on a study list to be discussed at interim legislative meetings later in the year.

So, for now, spice remains legal.

"We're having a lot of parents calling us, asking if it's legal and saying their teenagers are experimenting with it," said Salt Lake City's Ross. "It's targeted at youth; that's why we're so concerned about it."

Educators, too, have noticed the designer dope beginning to creep into schools. Granite district, for example, recently reprimanded two students for smoking spice, said spokesman Clay Pearce.

"It's very much a concern," he said. "We're in a watch and wait mode. But as word gets out, there will probably be an increase" in use among students.

The biggest worry for school officials continues to be alcohol and marijuana use by students, Pearce said. But those substances are both illegal for teenagers. With spice, it's unclear.

THC, and analogs like those found in spice, don't result in the same sort of physical addiction as drugs like heroin and cocaine, said the U.'s Hanson, who also is director of the Utah Addiction Center. Still, some users can develop a dependency on marijuana.

Marijuana and THC analogs stimulate the reward pathways in the brain, creating a sense of well-being and satisfaction, Hanson said. And that sets the stage for addiction.

csmart@sltrib.com