Glued-in hair extensions, if applied properly, last approximately 10 to 14 days. While the glue might continue to adhere the extensions to the natural hair longer than this, most stylist recommend removing the extensions after a couple of weeks to keep extensions looking great.
Most stylists do not recommend shampooing and conditioning while the extensions are attached. This means that people who wear extensions can only shampoo their hair after taking the extensions out.
Although extensions should be removed after a couple of weeks, they can be reused. After removal and proper cleaning, hair extensions can be reapplied to the natural hair with glue.