4-Chlorodehydromethyltestosterone, sold under the brand name Oral Turinabol, is an anabolic steroid. It is a chlor-substituted version of methandrostenolone (Dianabol). Turinabol was the first original product of Jenapharm, an East German pharmaceutical company. The patent registration took place in 1961. The idea of combining the structures of 4-chlorotestosterone and methandrostenolone originated from the chemist Albert Stachowiak.At the time this represented a unique dissociation of anabolic and androgenic effects after oral administration. The product had been introduced for clinical use in 1965.