When using a promotional or discount code, please enter the code at checkout into the 'Gift Card or Discount Code' section and click Apply. The discount code section is conveniently located on the right-hand side of the checkout panel, under the items currently in your cart. Only 1 discount or promotional code can be used per order. If you are experiencing any difficult in applying your code, please feel free to reach out to Client Care at clientcare@drdennisgross.com.