Does THCA flower go bad or lose potency?

It degrades rather than spoils — on two clocks. Chemically, THCA slowly converts and oxidizes toward CBN over months, drifting the experience weaker and drowsier; terpenes fade faster, which is why old flower tastes like hay. Physically, badly stored flower dries harsh or, worse, molds in damp conditions — the one genuine safety failure, and a reason to look before you grind. Well-stored flower (airtight, humidity-controlled, dark) stays respectable for six months to a year. This is also why COA test dates matter: a report from fourteen months ago describes a product that no longer quite exists.