Nandrolone, molecular model. Nandrolone is an anabolic steroid drug. It has been used illegally by athletes to increase strength and stamina. Overuse may cause liver damage, as well as virilisation (development of masculine characteristics) in women and infertility in men. It has also been used in the treatment of anaemia and osteoporosis, and as a hormonal contraceptive. The molecular formula is: C18.H26.O2. Atoms (spheres) are colour-coded: carbon (light grey), hydrogen (white), and oxygen (red).