Al Jazeera released a bombshell documentary that takes a look inside the world of performance-enhancing drugs in sports.
The documentary, "The Dark Side: Secrets of the Sports Dopers," hit YouTube before its airing on Sunday night, and alleges several NFL and MLB stars, namely Peyton Manning, have taken performance-enhancing drugs like human growth hormone (HGH).
SEE MORE: The man at the center of the bombshell Peyton Manning doping story has recanted his statements
The documentary follows as British track athlete Liam Collins works with Al Jazeera as an athlete looking to take performance-enhancing drugs (PEDs) to get one last boost before retiring.
The documentary investigates several doctors who allegedly are involved in the world of doping. Some of the stars who are named by the various doctors include:
Dustin Keller, a former NFL tight end.
Mike Neal, a linebacker with the Green Bay Packers.
Clay Matthews, a linebacker with the Packers.
Julius Peppers, a linebacker with the Packers.
Taylor Teagarden, an MLB player.
Ryan Zimmerman, a first baseman for the Washington Nationals.
Ryan Howard, a first basemen for the Philadelphia Phillies.
James Harrison, a linebacker for the Pittsburgh Steelers.
See photos of the players named in Al Jazeera's report
However, the biggest player named in the documentary is Peyton Manning, who one of the doctors, Charlie Sly, claims used to order HGH. Sly claims he was working for the Guyer Institute, an anti-aging clinic in Indianapolis when Manning played for the Colts, when Manning took HGH to recover from several neck surgeries. Sly said:
"[Manning] and his wife would come in after hours and get IVs and s***. So one thing that Guyer does is he dispenses drugs out of his office, which physicians can do in the United States. It's just not very many of them do it. And all the time we would be sending Ashley Manning drugs. Like growth hormone, all the time, everywhere, Florida. And it would never be under Peyton's name. it would always be under her name. We were sending it everywhere... it'd go to Florida... Almost all drugs you can prescribe off-label. GH is one of the few drugs, it's really the only drug you cannot prescribe off-label. It has three indications."
When the report came out, Manning denied ever taking HGH, calling the report "fabricated" and "trash," and saying it made him angry and upset. The Indianapolis Colts backed him and said Manning never took any PEDs while playing there.
However, Sly recently put out a statement, backtracking his claims.
"The statements on any recordings or communications that Al Jazeera plans to air are absolutely false and incorrect," Sly said. "To be clear, I am recanting any such statements and there is no truth to any statement of mine that Al Jazeera plans to air. Under no circumstances should any of those recordings, statements or communications be aired."
Dr. Dale Gruyer of the Gruyer Institution also released a statement, saying Sly was never an employee, but an unpaid intern, and that he doesn't believe the allegations are based on fact.
We have reached out to the NFL and MLB Players Associations for comment.
Watch the entire documentary below: