Everything I've been able to read on it says it is very fragile and must be refrigerated at all times. I also came across some info on it that stated that it must not be shaken to mix, only swirled gently. To re-constitute it is advised to run the water down the side of the vial and not spray it diectly onto the wafer for the same reason. This is all second hand from reading, I have not yet started using it, but thats what I've read so far.