Well, my hair was cut in a Halle Berry style exactly one year this month. My hair is now the length in the photo. I take a bunch of vitamins so I can't attribute any of it to one vitamin. However, my hair did grow a good amount. I also heard somewhere that zinc is suppose to strenghten the hair so it won't be prone to breaking. Also, I jumped on the zinc bandwagon because my friend takes a mulitvitamin, biotin, and zinc. She has good hair growth. She also exercises 2-3 times a week. I also take a combination of magnesium and calcium among other things.