Whitening products available for purchase in shoppes are designed to be "one size fits all" which often translates to "one size fits none".
The strength of the whitening product is much lower than what you can get in a professional kit, meaning that you must use the product for a longer period of time and are still unlikely to get the results you can find in a professional product. Additionally, your results are not being monitored by the dentist you know and trust.
