Hello. Thanks for writing to us at healthcaremagic The product you are using causes skin to become sensitive and thus prone to irritation if you also use something like a bleaching product, or do waxing, threading etc. However, having said that epiduo should not be used on upper lip area, as this area usually is acne free and moreover it is not recommended to be used near the naso labial folds, near angles of mouth. You may go through the package insert, it would be clearly mentioned. Once she stops using this cream on upper lips , she would be able to wax or thread as before. A dermatologist would have definitely told you the proper way to use it. Another option is to go Laser hair reduction, which is close to permanent/long lasting. Regards