City Council Speaker Melissa Mark-Viverito is joining forces with other elected officials to crackdown on synthetic marijuana. 

They are calling on the CEOs of three major websites to end the sale of substance.

Officials say eBay, Craigslist and Backpage are profiting by enabling people to purchase the drug known as K2. 

They say the websites are offering phone numbers and other links as a way for New Yorkers to purchase the substance. 

The drug is laced with unregulated chemicals and can cause serious health issues like seizures, rapid heartbeat and erratic behavior.  

City leaders are sending letters to the companies demanding that the ads come down.

"Synthetic marijuana is a blight in our city. It is a dangerous, unpredictable and illegal substance and for too long unscrupulous stores and online marketplaces have profited by peddling these deadly drugs to New Yorkers," Mark-Viverito said.

Last year, the state saw 300 hospital visits a week related to synthetic marijuana.

The City Council is looking to introduce a bill that would ban the sale of K2 in the city, raise civil penalties and shut down stores down stores that sell the drug.