An intramuscular dose of 12 mg/kg of this steroid anaesthetic produced sedation in cynomolgus monkeys, and higher doses (up to 60 mg/kg) produced light anaesthesia lasting up to 3 hours. Surgical anaesthesia could be induced by a single injection of 120 mg/kg, or by an intramuscular injection of 18 mg/kg followed by 6-12 mg/kg intravenously. No clinical or pathological effects were observed after daily use of the anaesthetic for 4 weeks.