Chlorodehydromethyltestosterone (also known as Turinabol) was created by the East German pharmaceutical company Jenapharm for Olympic and national-level athletes to use. It was patented in 1961. Oral Turinabol became a steroid of infamy during the 1990s, when it was revealed that chlorodehydromethyltestosterone had been one of the closely held secrets inside the "East German Doping Machine.” Because of its structural alteration compared to Dianabol, Turinabol does not aromatize and has low androgenic properties. Like any alkylated oral steroid, Turinabol adversely affects blood cholesterol levels (though not as much as stanozolol). It also reduces sex hormone-binding globulin (SHBG) and, as a result, increases the level of biologically active free testosterone in the blood. This explains the high synergistic effect when using Turinabol in a stack with other steroids, such as testosterone. Despite the fact that Turinabol is sometimes regarded as a relatively weak drug, it inhibits the hypothalamic-pituitary-testicular axis (HPTA) and suppresses the production of endogenous testosterone. Therefore, post-cycle therapy (PCT) based on antiestrogens is required for the quickest possible recovery of the endocrine system and to retain the results achieved during the cycle. Generally, Turinabol can be described as a milder analogue of methandienone without aromatization or water retention. 

WARNING: Due to its C17-alpha-alkylation, Turinabol may exert stress on the liver. Therefore, healthy lifestyle choices and the use of supplements to promote liver health are advisable. The overall recommended Turinabol cycle duration should be no longer than 6–8 weeks.