I give this product 5 stars because everything else I have ever used including hair skin and nails have not worked. I used this product for over 3 months over a year ago and it gave my hair amazing results. My hair was greatly damaged and thin from bleaching it so much. I used this and my hair grew thicker and much longer. The trick to all the low rating buyers is don't use heat on your hair and have some patience with the product. Use as recommended.