The sidewalks are wide and noisy along this stretch of Lexington Avenue in East Harlem, where people congregate in front of the Pathmark on the corner. The area is a gathering spot for the poor, homeless and drug addicted who stay in nearby shelters and visit the nearby methadone clinics. 

"Look at that guy over there," said one man, who would only give his first name — Edwin. "You see that guy over there sleeping? He’s on K2."

He pointed to a tall man sitting stooped over on a bench. Several people on this block have tried the drug. Edwin, a former heroin addict and current methadone user, said when he tried it with a friend he became paralyzed. "Locked up" was how he put it. 

"Everybody was smoking it and I took two drags with him and it didn’t do the same effect with him it done with me," the 54-year-old explained. "It sent me to the hospital. He went and got me the next day."

He and his friend swore they would never take the drug again. Both warned it was dangerous and should be taken off the market. City and state officials have been working to do just that, but it's proven to be a frustrating and futile process.  

K2, or synthetic marijuana, is basically herbs spiked with chemicals and drugs. People smoke it like they would a joint. The state banned the ingredients used to make it in 2012, but distributors found new ones. And just last month, the governor proposed banning those substances too. 

The drug comes in small packages labeled K2, Green Giant, Spice, Sand or Wicked. Vendors can face criminal fines or jail time, but first authorities have to prove that the chemical in the package is illegal.

"I bought it right from one of these stores here," said Scott DeHaven. "All the stores have them. Even though they say they’re not supposed to sell them, they got them under the counter right now."

DeHaven said he had a near-death experience when he smoked the drug. 

"My respiratory system shut down. I turned blue. They had to bring me to the hospital. I was throwing up on myself. They didn’t know what to do with me," he said.  

He described being intubated and said he was in the hospital for 16 hours.

Health officials have said the drug can cause a range of symptoms, from extreme anxiety, rapid heart rate and vomiting to sedation, paranoia and hallucinations. On Tuesday the NYPD released a video of police trying to apprehend a man on K2. He was naked and irrational, and at one point punched a hole through a wood fence with his bare fist.    

Between April and June, there were more than 1,900 emergency room visits across the state related to synthetic marijuana, and nearly 700 calls to the poison control call center. More than 120 people visited an emergency room in the city in just one week in April, New York City's health department said. The majority of those cases were in East Harlem, where person after person had a story to tell.

Kathryn Turner said she’s been smoking K2 for several years and now gets withdrawal symptoms without it.

"They can give you meth for heroin. They can’t give you something to withdraw from K2 because they don’t know. It’s a new drug," Turner explained. "If marijuana wasn’t so expensive I would smoke marijuana, I really would. But to be honest with you, I don’t smoke crack anymore because of K2. I know it’s bad to smoke K2, I’ll admit it, but in my mind, I’m not smoking crack so it’s okay." 

According to drug policy experts, one ounce of marijuana sells for around $400 these days. Turner said she pays $5 for a smaller packet of K2 and she can buy it across the street at the neighborhood bodega. The city has responded with raids by health inspectors, consumer affairs inspectors and the NYPD.

Eight thousand bags of synthetic marijuana were confiscated at five stores in East Harlem in early July. Three weeks later, another raid turned up 2,000 more at the LX Deli nearby. On a recent steamy Thursday afternoon, several police officers paced back and forth in front of the store. Eventually, they rushed inside and a deli worker came out to shut the store down. When a reporter asked whether he was caught selling K2, he seemed confused. 

"They asked me questions," he said. "I don't know. I just started working like months ago." 

A half-hour later, the deli worker was gone and the store opened again. 

When asked, the NYPD would not say whether the deli was, once again, selling K2.