The 34-year-old lineman, who signed a two-year deal with the Texans in March, said in a statement he did not knowingly or intentionally take a banned substance.
"Over the course of my 10-year NFL career, I have never engaged in the use of performance-enhancing drugs," Autry said. "Over that period, I have been subject to countless tests, none of which have ever returned a positive result.
"I was, therefore, stunned this off-season when I learned that one of my tests returned a positive result."
Autry's last season with the Tennessee Titans was the best of his decade-long career, having made 30 solo tackles and assisted on 20 others with 11.5 sacks and two fumble recoveries.
He apologized Monday to teammates and fans as well as the Texans organization, but placed blame on his pharmacy.
"A pharmacy to which my doctors submitted a prescription for a different medication, had, whether intentionally, recklessly, or negligently, included a banned substance," Autry said.
"I want to be clear -- at no time did I know or even suspect that this medication contained a banned substance."
He said his lawyers had provided the NFL with documentation "establishing that I neither asked for nor was prescribed any banned substances."
"It was important to me that the NFL know that I did not intentionally or even knowingly ingest a banned substance," he added.
That didn't stop the NFL from banning Autry for the first six Texans games of the upcoming 2024 season.
Autry will miss games against Indianapolis, Chicago, Minnesota, Jacksonville, Buffalo and New England before being allowed to return ahead of an October 20 game at Green Bay.
"I understand that under the NFL's policies, ultimate responsibility for what enters my body rests with me. To that end, while I intend to explore legal options pertaining to the circumstances that resulted in my positive test, I have accepted the NFL's punishment of a six-game suspension," Autry said.
The Texans will play Chicago on Thursday in the first pre-season contest ahead of September's start of the 2024 campaign.
