I'm a huge follower of Dr. Linkov. That said, I'm also an avid ingredient checker, and I have to say the ingredients, especially the active ingredients in this product, do not disappoint. I now use both the shampoo conditioner and thickening foam, but I've also tested the shampoo just by itself, and even with one rinse with the shampoo and no other product use, the hair strands are visibily thicker. (Female, long hair)