In our experience, fusion hair extensions should last up to 3 months, mostly depending on how much hair you had to begin with. Bonded hair extensions left in the hair longer than 3 months can result in unnecessary damage to your healthy natural hair and it is more difficult to keep them hidden and appearing seamless. Attaching extensions to shorter hair requires more frequent maintenance. You can also get more life out of your extensions by taking good care of them! We recommend brushing regularly, staying out of salt water and chlorine, using paraben and sulfate-free shampoo and conditioner, and making sure your hair is dry when you sleep to have the best experience with hair extensions. 52 E 11TH Street, New York, NY 10003212 221 - 3881Book Appointment Washing is vital to the upkeep of the fusion hair extensions. In a slow motion, wash the extensions from the top down while gently working the shampoo in, then rinse. Apply the conditioner to the mid shaft of the hair, all the way to then ends, working through the hair to help avoid tangles. Not to scrub too hard which could cause matting and/or breakage to their own hair.