Once an order has been placed with NationalAllergy.com, there may be limited options for cancellation or modification. Typically, the ability to make changes depends on the order status; if the order is still processing or has not yet been shipped, it is often possible to cancel or modify it. However, if the order has already been shipped, it is likely that changes cannot be made at that point. Customers are encouraged to review the order policies provided on the website for detailed information regarding cancellations and modifications. Additionally, looking at the current FAQ section might provide insights on procedures specific to your situation. If you require further assistance, please refer to the contact information available on the website for the most accurate guidance.