It lastsone season. I used to be in thedeer lurebusiness. We would keep it refrigerated before selling it. In between your hunts (during one season) keep it refrigerated, (not frozen). Toss it out after the season. I know it seems like a waste, but, the chemical make up changes & it doesn't have the correct smell to the deer's sensitive nose after it changes. It gets ammonia smelling & they can tell it's not fresh.
Use it liberally during your hunts to use it all up in one season. That way it doesn't seem like such a waste. Also, you can make a scrape with your own urine to throw them off. They will think it's a new buck in the area & they're ready to fight. I've never done that, because I'm a female. But, I know a lot of guys that I have talked with that have tried it & it does work, if it is not over done.