Methenolone (also known as primobolan) was described in 1960. Squibb Company began producing injectable drug in 1962. Methenolone originally was prescribed in case of muscle loss after operations, infections, long-term illnesses, aggressive therapy with corticoids or malnutrition, and in some cases it was used to treat osteoporosis and breast cancer. Methenolone was commonly used to promote weight gain in infants, weighing less than normal, without any side effects. Methenolone is an anabolic steroid, modification of dihydrotestosterone (DHT) with weak androgenic activity and a moderate anabolic effect. A notable trait of methenolone is that it can firmly bind to androgen receptors, stronger than testosterone. Adult doses for the treatment of aplastic anemia are usually in a range of 1–3 mg/kg per day. Adverse side effects include fluid and electrolyte retention, hypercalcaemia, increased bone growth and skeletal weight. In men, additional side priapism, azoospermia, hirsutism, male pattern baldness, acne andoedema. In women, side effects include virilization, amenorrhoea, menstrual irregularities, suppressed lactation, and increased libido. In children, side effects may include virilization symptoms. Metenolone may enhance effects of antidiabetics, ciclosporin, levothyroxine, warfarin. Resistance to the effects of neuromuscular blockers may occur, and metenolone also has the potential to interfere with glucose tolerance and thyroidfunction tests. Metenolone enanthate (methenolone enanthate) is an ester derivative of methenolone sold commonly under the brand names Primobolan (tablet form) orPrimobolan Depot (injectable). When it interacts with the aromatase enzyme it does not form any estrogens. It is used by people who are very susceptible to estrogenic side effects, having lowerestrogenic properties than nandrolone. This trait makes primobolan to be a good fat burner. Primobolan does not convert into estradiol. As an anabolic steroid, the use of metenolone is banned from use in sports governed by the World Anti-Doping Agency. Belarusian shot putter Nadzeya Ostapchuk was stripped of her gold medal after testing positive for metenolone at the London 2012 Olympic Games. She has been excluded from future IOC events. The NBA and NBPA also banned the use of methenolone under the Anti-Drug Program. In February 2013, Hedo Türkoğlu of the Orlando Magic was suspended for 20 games without pay by the league after testing positive for methenolone. In December 2013, Natalia Volgina was stripped of her 2013 Old Mutual Two Oceans Marathon title and received a two-year competition ban, subsequent to a final guilty verdict for using the steroid Metenolone.