4 to 12 weeks for the single strand hair extensions ( microrings , nanorings , keratin pre bonded and fusion bonding ).   Some hair grows faster than others but when the bonds have one inch regrowth (2.5 cm) it’s time to remove and re-apply them closer to the scalp using the same hair or replacing with new hair. It really depends on the natural hair density, lifestyle and aftercare.

Keeping your extensions over the recommended time can cause damage to your natural hair