The substance Clostebol is a defined as a mild anabolic steroid. It was initially developed in East Germany.
In medicine Clostebol is often used to treat skin conditions. It has however proven to be performance enhancing. It is on the prohibited list by World Anti-Doping Agency. The steroid mimics testosterone, but it does not break down into estrogen.
Clostebol is a Non-Specified substance, which is prohibited under category S1 of the 2021 WADA Prohibited List (Anabolic Agents), and therefore also prohibited under the Programme. Positive tests for Non-Specified Substances carry a mandatory Provisional Suspension.
Anti-doping tests can now easily isolate and identify Clostebol.
Sources: Drugbank (https://go.drugbank.com/drugs/DB15984),