The present invention provides formulations of cysteine knot proteins, including TGF-β superfamily proteins and bone morphogenic proteins that are pH stabilized. In particular, the present invention relates to the observation that certain buffers enhance the stability of cysteine knot proteins, including TGF-β superfamily proteins and bone morphogenic proteins. In particular, disclosed herein are liquid and lyophilized formulations prepared with a glycylglycine and tartaric acid buffers to stabilize the pH of the formulation.
