Nearly two dozen scientists and lab directors from around the world have signed a letter sent to the NFL and the players' association stating the current test for human growth hormone is safe, scientifically reliable and appropriate for use in professional sports leagues.
The letter, obtained by The Associated Press, was dated Oct. 3 and sent to NFL Commissioner Roger Goodell and union Executive Director DeMaurice Smith.
The NFL and the players agreed to begin blood testing for HGH as part of their new collective bargaining agreement, but only if the union agreed to the methods. The union has delayed implementing the test, asking for more scientific data to prove it is reliable.
The letter, signed by 23 scientists and lab directors, says, "Any suggestion in the press that its accuracy is a matter of debate is incorrect."
In another letter obtained by the AP, a separate group of anti-doping scientists and lab directors also endorsed the test.
"We want to take the opportunity to confirm that the test itself is scientifically accepted and has undergone extensive evaluation," says that letter, sent to Larry Bowers, the lead scientist at the U.S. Anti-Doping Agency, then forwarded by USADA CEO Travis Tygart to Goodell and Smith.
In all, about five dozen doctors, scientists and lab directors had their names on the two letters, which were sent to undercut the union's questions about the accuracy and validity of a test that produces an average of one false positive for every 10,000 tests conducted.
"This further demonstrates that there is simply no excuse for delaying the start of HGH testing in the NFL," league spokesman Greg Aiello said. "The scientific validity of the test is unquestioned. The abuse of growth hormone must be deterred to protect the health of our players and send the right message to young athletes in all sports."
NFLPA spokesman George Atallah said the union wanted to review the letters before commenting. The union has asked for more scientific information about the test so it can do its own analysis.
One of the key items the NFLPA is seeking is a population study of the test -- the data from the athletes who were used to originally set thresholds as to what constitutes a positive test. It wants to compare that data to a population study on football players; the union believes they could have naturally-high HGH levels, above those of other athletes.
The World Anti-Doping Agency, which sanctions the test, has declined to produce more information, per the union's request, saying plenty of data about the test is available and in the public domain.
The majority of those who signed the letters have some connection to WADA or its accredited labs. Those associated with labs linked to WADA are typically discouraged from making statements that question the agency's tests or procedures.
Tygart, in his cover letter to Goodell and Smith, said scientists at an international anti-doping symposium held in London earlier this month were "uniformly troubled" by the delays in implementing the test.
"The delay is troubling because the scientific validity, reliability and accuracy of the ... test is universally accepted and attendees at the Symposium recognize that the test is currently the best way to detect and deter the use of this dangerous, performance enhancing drug," Tygart's letter said.
Even the test's biggest supporters agree that the HGH test has a weakness in that it only detects synthetic growth hormone for around 24 hours after ingestion. But since the test was introduced in 2004, its accuracy has rarely been questioned this vehemently.
In an interview earlier this month, Atallah said there "are some certain, fundamental things we're asking for that are not insane."