Use an insulated travel case designed for insulin or medications—these are widely available and TSA-friendly. Reusable gel ice packs (not frozen solid—slightly thawed to avoid freezing the peptide) work well. For longer trips, a small insulated lunch bag with ice packs is adequate. Avoid placing vials in direct contact with ice packs; wrap them in a cloth or paper towel. Lyophilized (unreconstituted) vials are more temperature-stable and can tolerate room temperature for short periods.