Government officials are warning of possible health risks associated with another product sold in some so-called head shops: bath salts.

Synthetic stimulants are being sold at such shops nationwide as crystallized or powdered bath salts, and health officials are taking a closer look at the risks.

The Drug Enforcement Administration, which in late November announced an intent to ban the synthetic marijuana found in some head shops, considers the bath salts' stimulants, mephedrone and methylenedioxypyrovalerone, to be drugs of concern.

The agency is looking into whether the drugs should be controlled substances, spokesman Rusty Payne said. Florida and Louisiana have banned them, and other states are considering doing so.

Kirk Hughes of the Minnesota Poison Control System emphasized they're not the same as aromatic bath salts sold at such stores as Target and Walmart.

The most common way to get the salts is online, he said. Ivory Wave and Vanilla Sky are the two most popular brands in Minnesota. The stimulants also are sold as plant food, "which is total B.S.," Payne said.

Users eat, smoke, inhale or inject the salts, Hughes said. Just as products such as K2 and Spice "incense" were marketed as legal alternatives to marijuana, certain bath salts now are perceived as legal alternatives to cocaine, LSD and methamphetamine, Payne said.

Since November, state poison control officials have received five calls from health care professionals treating users. They were from 20 to 43 years old and experienced effects ranging from an increased heart rate and blood pressure to nausea, vomiting, confusion, agitation and hallucinations, Hughes said. None was seriously injured.

Nationally, however, at least one woman overdosed, and one man shot himself, allegedly under the influence of bath salts, according to the Associated Press.

U.S. poison control centers received 220 calls regarding the bath salts so far this year, said American Association of Poison Control Centers spokeswoman Jessica Wehrman. That compares with 236 such calls in all of 2010.

The DEA says costs for synthetic stimulants vary, with a "dose" of Ivory Wave going for as little as $10 to $25. Employees at several tobacco and glassware shops in Minnesota said their stores haven't sold the salts.

"It's not really our thing," said Claire Paczkowski at the Hideaway in the Dinkytown area of Minneapolis.

At the Last Place on Earth shop in Duluth, owner Jim Carlson said bath salts under the brand name "Eclipse" are selling well. But Carlson said he and his staff are debating pulling the product because of negative attention similar products have gotten.

Hughes said the challenge lawmakers and regulators face is that chemists can simply "tweak" the formula to create an "analogue" that is technically legal.

"I really don't know what the answer is," he said. "People will just keep making an analogue that's not specifically identified in the legislation."

Katherine Lymn is a University of Minnesota student on assignment for the Star Tribune.