If you look on the website in the My Teachers web pages, you should fine a news letter on TOPKNOT which is my version of the Dr/ Christopher theories on grey hair. It works for my hair, but have no clue how it will work for others...many have liked it. I think it got left off the newer price list about a year ago, so you may not find a price for it. It is $21.00 for a 8oz spray bottle that last a long time.