supposedly the 1-test lasts a while like a shelf life of 2 years or something i read on another board and the 4 ad is less, about half, before it drops something like 10 percent over that period of time, so its nothing crazy. some say that by freezing you may be able to prolong life even more, however dont quote me. lets see what others say. also, if you do a search there is tons of info on this i remember too. i had mine for about 8 months no freezing and it seems to be working just as good as the cycle befor it