Collins, in his third season with the team, tested positive for Growth Hormone Releasing Peptide-2 (GHRP-2), the league said.
Collins told ESPN’s Adrian Wojnarowsi that he will appeal the suspension.
“First I want to apologize to my teammates, the Hawks organization, our fans, partners and community as a whole for this situation,” Collins said in a statement to Wojnarowski. “I understand the impact this matter has on what we are trying to achieve together this season, and I am incredibly frustrated and disappointed in myself for putting all us in this position.
“I have always been incredibly careful about what I put in my body, but I took a supplement, which unbeknownst to me, had been contaminated with an illegal component. I plan to appeal my suspension in arbitration so I can get back on the court as soon as possible and continue to contribute to our 2019-20 campaign.”
Collins is averaging 17 points and 8.8 rebounds in 32.2 minutes per game this season.
His suspension will begin with Tuesday night’s game against the San Antonio Spurs.