After the treatment, the longevity of your straightened hair can vary based on your hair’s natural texture, care routine, and environmental factors. On average, you can expect your hair to remain straight for around 2 to 3 months. To prolong the results, use sulfate-free, gentle shampoos and conditioners, avoid excessive heat styling, and protect your hair from humidity. Regular touch-ups and proper maintenance will help you enjoy your straightened hair for an extended period.