If a peptide must stay refrigerated, checked luggage is a poor fit unless the product documentation specifically allows the expected travel temperature range
The $300 peptide problem The economics of peptide research create a paradox
Buie T, Campbell DB, Fuchs GJ 3rd, Furuta GT, Levy J, Vandewater J, Whitaker AH, Atkins D, Bauman ML, Beaudet AL, Carr EG, Gershon MD, Hyman SL, Jirapinyo P, Jyonouchi H, Kooros K, Kushak R, Levitt P, Levy SE, Lewis JD, Murray KF, Natowicz MR, Sabra A, Wershil BK, Weston SC, Zeltzer L, Winter H
AOD 9604 responds better to gentle hydration than to speed
For peptides, this molecular bumping and shaking can cause the amino acid chain to snap