You guys think all those bottles at Walmart or your LGS were shipped in a refer truck? I be they've seen plenty of heat both there and in storage. I wonder if that's why they don't work that well.
I've never looked and examined a package, but look for an expiration date somewhere on the package.....I'm thinking you won't find one.
I've used tinks and had deer come in and not be spooked, and the one I like to use now is made by "Trails End" brand.
I've had bucks come in raise their heads and flare their nostrils. They would then just walk away.....More like out of curiosity.