Testing for human growth hormone began in the NFL on Monday.

The NFL will conduct 950 tests in the preseason and another 385 in the offseason. Compared to baseball, which conducts about 400 HGH tests per year, the NFL’s effort is much more thorough.

According the new drug testing policy, which was adopted in September, five players from eight teams will be tested each week. No testing will take place on game days.

“We negotiated to ensure that the methodology of testing be conducted in the most professional and safest manner for players. Importantly, after three years of negotiating, players won the right to challenge any aspect of the science behind the HGH isoforms test in an appeal of a positive test,” NFLPA president Eric Winston said in a letter to players.

The appeals process, which was a stumbling block in the negotiations for a new policy, will be heard by a neutral person, not by NFL Commissioner Roger Goodell or someone he designated.