The federal government intends to make a deadly derivative of the powerful painkiller fentanyl a controlled substance, according to a notice posted Friday.

Acryl fentanyl has lead to dozens of deaths and has been perfectly legal to purchase. The opioid is considered to be more powerful than fentanyl and highly resistant to naloxone, an overdose antidote commonly known as Narcon.

The designer drug has lead to at least 83 confirmed overdose deaths in five states in 2016 and 2017, according to Chuck Rosenberg, acting administrator of the Drug Enforcement Agency. NBC recently reported that the drug killed 44 people in Chicago alone through April 8.

The notice posted Friday says that the DEA will add acryl fentanyl to list of Schedule 1 drugs for two years at some point after July 2.

The Schedule 1 classification is for drugs that “have a high potential for abuse, no currently accepted medical use in treatment in the United States, and a lack of accepted safety for use under medical supervision.”

Examples of other schedule 1 drugs are heroin, marijuana, and lysergic acid diethylamide (LSD).