Provided are salt-free antibody and other protein formulations that are substantially isosmotic and of low viscosity. In particular, provided is: A salt-free anti-TFPI antibody formulation, comprising: 10 mM to 30 mM histidine； 50 ppm to 200 ppm of a non-ionic surfactant； 88 mM to 292 mM of sucrose； 10 mM to 50 mM arginine； 0 mM to 50 mM lysine； 0 mM to 133 mM glycine or alanine； 0 mM to 10 mM methionine； and 1 mg/ml to 150 mg/ml of anti-TFPI human IgG2 antibody having a light chain comprising the amino acid sequence of SEQ ID NO: 1 and a heavy chain comprising the amino acid sequence of SEQ ID NO: 2, wherein said anti-TFPI antibody formulation has a pH of pH 4.0 to pH 6.0, and wherein said anti-TFPI antibody formulation contains substantially no inorganic salt. Also provided is the use of these formulations in the manufacture of medicaments for the treatment of disorders in patients.
