New York City is a major destination for drug traffickers from around the country, according to the Drug Enforcement Administration, and now a new dangerous drug is making its way into the streets.

Carfentanyl is an elephant tranquilizer that dealers are now cutting into other drugs.

It's even deadlier than fentanyl, a synthetic opioid that can be up to 50 times more potent than heroin, according to Special Agent in Charge James Hunt, of the DEA's Northeast Regional Drug Lab. He has taken down major drug traffickers, including gang and cartel members.

"Carfentanyl is 100 more times powerful than fentanyl alone," he says. "And that is why we're seeing the number of overdose deaths in the U.S. right now."

He says in drug houses, distributors are often cutting heroin with other substances to save money. The results are deadly and have led to a spike in overdoses.

"The people here are mixing it on a kitchen table in the Bronx," he says. "They're not real chemists. They're not trained, putting too much in and killing the user."

Real chemists working for the DEA have analyzed seized drugs and often been called to court to testify on their chemical makeup and purity.

Fentanyl and carfentanyl can be so powerful in some cases that people can overdose just from touching it, Hunt says, so investigators have had to change their tactics to adapt.

"There's a real physical danger with the product itself," he says. "You can get sick by just touching it."

And technology has also changed, altering the way investigators track traffickers' finances as many switch to digital currency like Bitcoin.

As for drug users -- Hunt says now is a better time than ever to seek treatment as street drugs grow deadlier.