"Obviously, it's becoming a trend that we need to get ahead of," says Fairfax County Police Chief Ed Roessler.
Fairfax County has had 168 cases involving "Molly" between January 2012 and last month. Police have confiscated 16.7 pounds of the drug in its powder form, and more than 3,000 pills in that time.
Roessler says best line of defense against the drug remains parents and schools and awareness of the signs of drug use.
"It's gonna involve a lot of education and prevention in the school districts, which we are doing to hopefully stop people from using it", he says.
The drug has been linked to at least one death in this region - a University of Virginia student who died after using the drug after a visit to a D.C. nightclub.
The drug can have dramatic impact. Short-term effects include confusion, strange cravings, sleep problems, memory loss, blurred vision, fever, rapid eye movement and profuse sweating.
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