Turinabol

Chlorodehydromethyltestosterone, more fully 4-chlorodehydromethyltestosterone and commonly called by its former brand name Oral Turinabol, is a synthetic anabolic-androgenic steroid of the androstane family. Chemically it is the 4-chloro-substituted form of metandienone, the steroid marketed as Dianabol, and it carries a 17-alpha-methyl group that makes it active when taken by mouth. The chlorine substitution was intended to give a favourable separation of anabolic from androgenic activity, and it binds only weakly to sex hormone-binding globulin.

The compound was created at Jenapharm, the East German pharmaceutical company, where it was the firm's first original steroid; it was patented in 1961, credited to the chemist Albert Stachowiak, who combined structural features of 4-chlorotestosterone and metandienone, and it entered clinical use in 1965 ^[1]. It was prescribed for a range of conditions in which an anabolic agent was thought useful, and manufacture continued until the mid-1990s.

Turinabol is best known for its part in organised doping. Under a secret programme known as State Plan Topic 14.25, the government of the German Democratic Republic administered the drug to thousands of its athletes over roughly two decades, frequently without the athletes' informed knowledge and including minors, in a systematic effort to improve international sporting results; the programme, later exposed through recovered documents, caused lasting harm to many of those involved ^[2].

As an androgen receptor agonist, turinabol produces the muscle-building and masculinising effects characteristic of its class, and its oral activity and weak binding to sex hormone-binding globulin distinguish it pharmacologically. It is metabolised in the liver and excreted in the urine.

Because traces of its breakdown products persist long after use, turinabol has become important in anti-doping science. Investigators characterised novel long-term urinary metabolites that greatly extended the detection window, and improved methods were later used to reanalyse stored Olympic samples and to synthesise reference standards of these metabolites ^[3][4]. The drug is a controlled anabolic steroid in many countries, classed as a Schedule III substance in the United States and as a controlled drug elsewhere, and its side effects are those of anabolic steroids generally, including liver strain from the 17-alpha-methyl structure, suppression of natural hormone production, cardiovascular effects and virilisation.

Turinabol (4-chlorodehydromethyltestosterone) is a C17-alpha alkylated oral steroid, so it is hepatotoxic; it strains the liver and can drive sharp elevations in liver enzymes, with the alkylation being the reason it survives first-pass metabolism at all. Being non-aromatizing and resistant to hepatic breakdown, it hits the lipid panel hard, suppressing HDL and raising LDL, which compounds cardiovascular and atherosclerotic risk over a cycle.

Like all exogenous androgens it suppresses the hypothalamic-pituitary-testicular axis, lowering LH and FSH and shutting down natural testosterone production, so post-cycle recovery is slow and PCT is generally needed to restore function. Additional documented concerns include raised hematocrit and blood pressure, mood changes, and virilization in women (voice deepening, hair growth, menstrual disruption) that can be irreversible. It also carries a long detection window and was central to state-sponsored doping, so athletes face a real testing liability on top of the physiological risks.