Abstract: A composition and method for controlling host response to organ and/or tissue transplantation and grafting. Alpha-Melanocyte Stimulating Hormone protects organ and tissue transplantation by controlling factors within the donor, host and of the organ or tissue to be transplanted. Treatment with &agr;-MSH and/or its derivatives can affect warm and cold ischemia times and thus promotes organ viability. Treatment of the donor, host and of the organ or tissue to be transplanted with an appropriate dosage of &agr;-MSH and/or its derivatives limits biochemical pathways that would normally work to reject an organ and/or tissue transplantation. &agr;-MSH augments successful graft transplantation whether it be allograft or xenograft.