The only "bath salts" I know go in the tub, not the versions I've been reading about in the headlines. I'm talking about the Miami man who ate another man's face, in a zombie-like state, after he allegedly took bath salts. Turns out he only had marijuana in his system, but many recent violent attacks are being blamed on bath salt highs.

The drug's innocuous name is meant to throw off law enforcement as it delivers a “legal high”. These designer drugs show the increasing sophistication of underground chemists to mimic the high of an illegal drug and skirt the law. Bath salts act on the central nervous system, much like speed and cocaine, except its effects are less predictable.

Since “street chemists” are mixing the drug, no one knows exactly what's in them. The main synthetic compounds in bath salts are MDPV, mephedrone, and methylone, but there are many others. They're synthetic derivatives of cathinones. Cathinones are stimulants naturally found in the Catha edulis plant, which has long been illegal in the US. But the synthetic derivatives are far more concentrated.

Bath salts affect behavior by altering levels of the neurotransmitters norepinephrine, dopamine, and serotonin. These neurotransmitters are responsible for our fight or flight response, movement, and emotional responses, sleep and appetite, along with numerous other behavioral and physiological functions. Bath salts raise the concentrations of these neurotransmitters, allowing them to react freely with brain receptors instead of being safely stored in brain cells. The effects are extreme paranoia, vivid hallucinations, and full-blown psychosis.

A year ago, when reports of violence caused by bath salt abuse surfaced, U.S. Drug Enforcement Agency banned the key ingredients in the drug for one year starting October 2011. But, unfortunately, they're still legally sold on the internet and in truck stops around the country.