The present invention features methods for treating or ameliorating tissue damage using intravenous administration of compositions that include stromal cell derived factor-1 (SDF-1) peptides or mutant SDF-1 peptides that have been mutated to make them resistant to protease digestion, but which retain chemoattractant activity. Systemic delivery, and specifically intravenous (“IV”) delivery, of SDF-1 and protease resistant SDF-1 mutants is very effective for the treatment of tissue damage.