Effect of Formulation on Stability

Below is a figure that shows how expiration dating varies by formulation. For standardized products, these dates were established through FDA-approved testing methods. For non-standardized products, these dates were established by the FDA. For more information on extract formulation, please see the section on Extract Formulations

Expiration dates for bulk concentrates are assigned based on the fomulation of the product
Glycerinated	Maximum of 3 years
Aqueous	Maximum of 18 months. Short ragweed extracts receive a maximum of 12 months due to the measured lower stability of the ragweed proteins.
Alum-precipitated	Same as Aqueous
Lyophilized(freeze-dried**)	Maximum of 5 years of unreconstituted andrefrigerated. Once the product is reconstituted, the maximum shelf life becomes 12 months at the highest concentration.

Currently only available for Hymenoptera Venom