Pharmaceutical sales representatives must now pay $750 annually for a license from the city but also undergo ethics training and disclose "their practice and products" to Chicago residents, officials said.
Complaints about pharmaceutical representatives can be made through the City’s 3-1-1 system.
"This improvement will help ensure both physicians and residents have accurate information about medications, including the potential for addiction," said Chicago Department of Public Health Commissioner Dr. Julie Morita. "As this new license shows, Chicago is leading the nation in holding drug companies accountable and creating innovative safeguards for residents."
People who violate the requirement could face fines of $1,000-$3,000 per violation, and could have their license revoked for at least two years, officials said.
In 2016, there were approximately 684 opioid-related deaths in Chicago, according to data from the Cook County Medical Examiner's Office.
That represents an increase of nearly 97 percent from 2015, according to the data.
"Evidence shows that addiction to prescription opioids is often a gateway to heroin addiction and law enforcement officials report the illegal heroin trade is a catalyst for other crime," according to a statement from the mayor's office.