I'm certainly not one to take time and write a review, but I will.... I've used the other vitamins posted here and therefore feel my comparisons have been thorough. Hair Formula works the BEST. Yes, it is a bit tedious to take so many vitamins throughout the day - but once you're in the habit, you don't even think about it.It not only makes your hair grow, but makes your nails fabulous! It reminds me of the intense results of taking pre-natal vitamins and how my hair and nails grew agressively when I was pregnant with my daughter.Human hair grows only 1/4 an inch each month. Mine has grown a full 1/2 inch each month. This is a wonderful product! For anyone who claims it is not, I'm convinced they did not take it regularly. The shampoo and conditioner are great too.For as long as I've been taking the product, my naturally blonde - very curly hair - which means it is naturally dry and weak - has become stunning and looooong.Thanks for reading and enjoy the product!