QF has a two year shelf life. If you look on the enclosed directions sheet, theres an alphanumerical date code on it. This is when the shelf life begins. For example if the code reads "F10B06", that means the batch was made in the second week of Oct '06.

The people who claim to have problems with the QF were obviously not doing their homework. Either they werent making practice runs on maintaining the temperature, or they did not home test the bottle beforehand to see if the urine constituent levels are within acceptable limits. Adulteration test strips are used to check these levels and can be easily found online by doing a Google search.