This featherweight serum mends split ends caused by chemical or styling damage & heat. Creates an ultra-durable bond to seal & protect hair. Joico K-Pak Split End Mender polishes & strengthens your hair to seal split ends while helping to prevent new ones from forming. p H 5. 8-6. 3. Directions: Joico K-Pak Split End Mender works best when: Applied to clean, damp hair, focusing on the ends Combed through & left in the hair.