Tetrahydrogestrinone identified in a spent syringe

Tetrahydrogestrinone, a previously unidentifiable designer steroid, has now been identified by researchers from the UCLA Olympic Analytical Laboratory in Los Angeles.
THG (Tetrahydrogestrinone) was identified after a spent syringe was anonymously provided to the United States Anti-Doping Agency (USADA).
From News-Medical.Net:

Urine samples were purposely spiked with the newly identified THG and various analyses carried out to determine [...]