The memo closes by saying: "This hearing will examine the science behind current HGH testing and highlight the fact that this testing is available to use in the NFL."
In a statement issued Tuesday previewing the hearing, committee chairman Darrell Issa, a California Republican, sent something of a warning to the NFL and players.
"There has been a frustrating lack of progress on testing. The possibility that federal legislation could eventually be adopted to address this problem may be unlikely at this point, but the league and its players would be unwise to ignore it," Issa said.
The committee did not ask anyone from the league or union to testify Wednesday. Scheduled witnesses include Pro Football Hall of Fame member Dick Butkus, U.S. Anti-Doping Agency Chief Science Officer Larry Bowers, and National Institutes of Health Deputy Director Lawrence Tabak.
In written testimony submitted to the committee, Bowers says "there is a broad consensus among scientific experts who regularly work in the growth hormone field" that the test is reliable and valid, and that "the chances of an athlete who has not used synthetic growth hormone testing positive are comparable to the chance of that same athlete being struck by lightning during his or her lifetime."
Bowers writes that World Anti-Doping Agency records show that as of late August, 12 positive results showed up from 12,764 HGH tests around the world.
"I would like to point out that the only people who are still questioning the methodology and validity of the ... test are lawyers, not scientists," his testimony reads.
Tabak's written testimony says many studies vouch for the reliability of HGH testing, even though the naturally occurring hormone and the artificial form are "virtually indistinguishable." He adds: "Questions can always be raised about whether a given test, even one whose reliability has been established under most circumstances, also has universal validity. ... In science, universal validity is almost never achievable. ..."