Plasma Heparin Levels in Normal Man

Endogenous plasma heparin levels were determined in duplicate in 153 males and 103 females. Heparin is normally present in human plasma in values ranging from 10 to 24 units per cent (1 to 2.4 mg. per liter). The range of average values was from 1.53 to 1.77 mg. per liter. No age or sex difference was found.