Why is 2nd day shipping required?

This product is sensitive to temperature and requires expedited shipping in a cold pack in order to protect its quality and potency. When this product is added to your cart, your shipping option will automatically adjust to expedited shipping. You may not change the shipping option -- unless the product receives expedited shipping, we cannot guarantee its condition upon arrival. To ensure product integrity, once you have received the product, please adhere to the instructions regarding refrigeration. Failure to follow those instructions could impact the product and is the responsibility of the purchaser. Products that must be shipped in a cold pack are not eligible for free shipping promotions.