New York (CNN) -- The "bath salts" arrive in quarter-size plastic containers showing a sun lingering over a blue horizon and the promise "to energize your mind, body & soul."
These are not actually bath salts -- they're dangerous synthetic stimulants that look like cocaine, with similar effects.
When inhaled or ingested, the white powder can cause paranoia, hallucinations, convulsions and psychotic episodes.
Poison control centers around the country are reporting an uptick in calls about "bath salts." And according to authorities, people have ended up at emergency rooms and in psychiatric wards after taking the stimulant.
"They might take it one day and be fine and take it another day and they might actually die," says Special Agent Gary Boggs of the Drug Enforcement Administration.
MDVP or methodrone was recently banned in Louisiana and Florida. Sen. Charles Schumer has called for the chemical to be put on the controlled substance list.
Sold at tobacco shops, gas stations, and head shops, the drug can also be bought on the internet.
"With drugs like these, there's no back street alleyway where you're meeting your drug dealer," says Boggs. "You googled your drug dealer and got it delivered to your own home with a credit card."
One online distributor said demand for the brand "Bliss" was so high, the suppliers had sold out. Instead, the seller promised to send two 500 mg vials of a similar product, "Serenity Now," with twice the potency.
The DEA is trying to alert young people and parents about the dangers of "bath salts," which are undetectable in drug tests.
MDPV blocks the neurotransmitter chemical dopamine from being reabsorbed into the brain. When it's used over the long term, the brain stops manufacturing dopamine, which affects a person's ability to feel pleasure.
"That consequently turns into paranoia, anxiety and can be very dangerous," says Boggs.
Police in Panama City, Florida, have attributed two violent incidents to the use of these drugs. They said a woman who snorted "bath salts" allegedly tried to behead her 71-year-old mother. They also said a man on "bath salts" used his teeth to tear up the back seat of a patrol car.
Authorities say the chemicals are made in places like China, Pakistan and India. There are no manufacturing regulations and often no listed ingredients.
"You just don't know what you're buying (or) what you're putting in your body," says Boggs.