How long do cooling pillows last before they go flat?

Verified-purchase reviewers across Amazon, Walmart, and Target generally report 1-2+ years of solid performance from shredded memory foam pillows, with adjustability extending useful life. Solid memory foam pillows draw more complaints about losing firmness over time, and r/Mattress threads specifically warn that some Tempur-Pedic foam pillows can soften noticeably 6-24 months in.