Hey Britt and CrowningGlori, I am not sure, now my granny swears it makes the new growth grow in thicker and my cousin did this for a month prior to her touch-up and said that for the first time in her life she had thick bouncy hair the day of the touch-up. I apply mine then jump in the shower before bed and next day I have nice thick hair. Maybe it does both, make new growth come in thicker and plumps up the strands coz the results are practically over night.