Un-mixed HCG vials can be stored in the fridge or a cool and dark drawer. However when mixed up the constituted liquid MUST be stored in the fridge at all times and only taken out shortly for the injection. Do not freeze your HCG. Unmixed bottles are good for max. 2 years (check label). The mixed substance is potent for 40-60 days. In case you have 2 bottles HCG for your program, mix one first and use it up, then mix the second one.