Protein C, an anticoagulant protein, is increased in healthy volunteers and surgical patients after treatment with stanozolol.

On both oral and intramuscular administration, the anabolic steroid stanozolol was found to increase protein C antigen concentrations in circulating blood. In fourteen healthy young volunteers (who received stanozolol orally, dose 10 mg/day) the average increase was 1.5-1.6 times the normal concentrations after 3-6 weeks' treatment and was accompanied by more moderate increases in the other vitamin K-dependent factors II, IX and X to 1.4, 1.4 and 1.2 times their normal concentration respectively. However, there was no change in factor VII. In sixteen elderly surgical patients, intramuscular injection (50 mg) one day prior to surgery induced a moderate increase within 24 hours (to 1.11 times the pretreatment concentration) and seven days after operation (to 1.19 times), and reduced the postoperative fall in protein C. Stanozolol administration seems to be a promising pharmacological method for increasing anticoagulant protein C levels in congenital and acquired deficiencies.