Unmixed HCG - should ideally be kept in the fridge, or in cool conditions (but not frozen).
Mixed HCG - MUST be kept in the fridge (but not frozen).
Pre-mixed HCG - As in sealed pharmaceutical grade that very very few people would have access to, should ideally be kept in the fridge as per unmixed, but once it is opened, it MUST also be kept in the fridge.