The only definitive sign is the beyond-use date stamped by the pharmacy or a known temperature excursion (vial left out for more than 4 hours or frozen)
Schernthaner G, Shehadeh N, Ametov AS, Bazarova AV, Ebrahimi F, Fasching P, Janez A, Kempler P, Konrade I, Lalic NM, Mankovsky B, Martinka E, Rahelic D, Serafinceanu C, Skrha J, Tankova T, Visockiene Z
Differential regulation of glutathione S-transferases in cultured hepatocytes [PMID: 2912828] Laboratory literature summary: Differential regulation of glutathione S-transferases in cultured hepatocytes
is 3.9 years, the Bureau of Labor Statistics reports