Disclosed are pharmaceutical compositions comprising a thrombin peptide derivatives and a chelating agent and/or a pharmaceutically acceptable thiol-containing compound. The pharmaceutical compositions optionally further comprise an antioxidant. Also, disclosed are methods for activating the non-proteolytically activated thrombin receptor in a subject in need of such treatment. The methods comprise the step of administering an effective amount of a thrombin peptide derivative in the pharmaceutical composition described above.