From the above article:
"Even before BALCO broke, Arnold was suspected by anti-doping officials as the man who resurrected the steroid norbolethone, a drug that was manufactured in the 1960s but never marketed to the public. The substance was discovered in the urine sample of an athlete in 2002. Based on e-mails and documents seized in the BALCO case, authorities believe norbolethone was the first generation of "the clear" distributed by Conte to elite athletes.
By the time of the BALCO raids in 2003, "the clear" was a newly designed steroid called tetrahydrogestrinone, or THG."