The short version: nine to fourteen days is normal, the pack is spent within two, and the solid does not mind.
Reported ranges from Chinese origins to western Europe cluster around nine to fourteen days with tracking, with inland origins adding a domestic leg and coastal ones sometimes beating the range.
Tracking quality is the more informative signal: continuous scanning at every hop indicates a real logistics chain, and a tracking number that goes dark for a week indicates something else.
Solid-state stability of lyophilised peptides at ambient is well documented in formulation studies, with residual moisture as the dominant variable.
Nothing here is medical advice, and research-use compounds are not approved for human use.
Buy a data logger if the temperature history genuinely matters to you.
edited 28 Apr 2025 by shear_at_the_front — tightened the wording; no substantive change